Hydroponics & Aquaponics

  • function of Potassium (K) in plants

    Potassium is a paramount macro-element for overall survival of living things. It is an abundant mineral macronutrient present in both plant and animals tissues. It is necessary for the proper functioning of all living cells. Potassium is relatively abundant in the earth's crust making up to 2.1% by weight. Potassium is mined in the form of potash (KOH), sylvite (KCl), Carnallite and Langbeinite. It is not found in free nature.

    Importance of potassium to plants

    Potassium is an indispensable constituent for the correct development of plants. It is important in photosynthesis, in the regulation of plants responses to light through opening and closing of stomata. Potassium is also important in the biochemical reactions in plants. Basically, potassium (K) is responsible for many other vital processes such as water and nutrient transportation, protein, and starch synthesis.

    Potassium Uptake

    Bio-availability and uptake of K by plants from the soil vary with a number of different factors. The rate of respiration by plants is largely the determining factor for proper uptake and transport of potassium by plants. Its uptake is dependent on sufficient energy (ATP). Potassium plays a vital role in the translocation of essential nutrients, water, and other substances from the roots through the stem to the leaves. It is also made available through fertilizers in the form of K2O. Plant tissues analyze the form of these fertilizers and convert it into a more bio-available form. It is absorbed in the form of ions- K+.

    Functions of Potassium in plants

    Potassium (K) essentially plays a major role in plant physiological processes. Therefore, it is required in large amounts for proper growth and reproduction in plants. It is considered vital after nitrogen as far as nutrients needed by plants are concerned. It is also termed "the quality nutrient" for its contributing factor in a number of biological and chemical processes in plants. Here is why Potassium is important in plants:

    • Potassium regulates the opening and closing of stomata thus regulating the uptake of CO2 thus enhancing photosynthesis.
    • It triggers activation of important biochemical enzymes for the generation of Adenosine Triphosphate (ATP). ATP provides energy for other chemical and physiological processes such as excretion of waste materials in plants.
    • It plays a role in osmoregulation of water and other salts in plant tissues and cells.
    • Potassium also facilitates protein and starch synthesis in plants.
    • It activates enzymes responsible for specific functions.

    Potassium deficiency in plants

    Regardless of its availability from soils, potassium deficiency may occur and might start from the lower leaves and progress towards other vital parts of the plants. Deficiency might cause abnormalities in plants affecting reproduction and growth. Severity depends on with the type of plant and soil. Some of the potassium deficiency symptoms may include:

    • Chlorosis: May cause yellowing of leaves, the margin of the leaves may fall off, and also lead to shedding and defoliation of the leaves.
    • Stunted growth: Potassium being an important growth catalyst, its deficiency or insufficient might lead to slow growth or poor developed roots and stems.
    • Poor resistance to ecological changes: Reduced availability of potassium will directly result in less fluid circulation and translocation of nutrients in plants. This will directly make plants susceptible to temperature changes.

    Importance of potassium in agriculture

    Potassium is important in agriculture and soil gardening. It is used as a constituent in artificial fertilizers. Potassium fertilizers have been seen to increase crop yields, enhance production of grains rich in starch and protein content of plants. Additionally, potassium fertilizers may help improve plants immunity to weather changes, diseases, and nematodes.

    Potassium is majorly used in hydroponics to improve root growth and enhance drought tolerance. It also enhances the building of cellulose and thus reduces lodging.

  • Growing Cherry Tomatoes in Aquaponics

    Cherry Tomato: -Â

    Tomatoes are an excellent summer fruiting vegetable to grow using all available methods although physical support is necessary.

    A higher nitrogen concentration is preferable during the early stage to flower stage. However, potassium should be present from the flowering stage to fruit setting to growth.

    Tomatoes are rich in vitamins A and C, low in calories and a source of lycopene (the "Red" in tomatoes), which has been tapped as a cancer-fighting agent.

    If you have experience in growing tomato you know that to get the high-quality products and good yields with a limited space can be quite a challenge.

    We'll try to consolidate all important things that you need to know if you want to grow tomatoes, have high-quality products and great yields in your greenhouse. We'll also share our experience and you'll see great benefits of aquaponic systems for profitable commercial tomato production.

    Tomato is one of the most demanded vegetables. In the season but also out of the season. It is used as a fresh produce but also an input for the production of many different products like sauces. One of the greatest advantages is that it grows in the air and we can use a lot of greenhouse height for our production.

    The main advantages of growing tomatoes in protected spaces (greenhouses) compared to other crops are:

    • It is highly attractive and demanded product
    • We can have very high yields per sqm
    • There are many hybrids that are resistant to diseases.

    Growing Conditions: -

    • When you have set up your aquaponic system and decided to grow tomato you need to pay attention to some details. If you make mistakes, in the beginning, you will not see problems usually until it's too late to fix them.
    1. Type of aquaponic system?
    2. How to band tomatoes for the best vertical growth?
    3. How to make tomato grow faster?
    • Each and every part of the aquaponic system that is not synched to specific natural laws can create problems in the future. These problems can be insignificant but sometimes these problems can lead to total disaster. For that reason, it is important to have all the information and to understand each part of the system.
    • The first and most important factor is to choose the right aquaponic system for tomato production.
    • Out of all aquaponic systems, BED system is probably the most convenient for many types of crops. But it is not a profitable system. Because it is quite robust, it takes a lot of space and is quite expensive to construct.
    • For profitable tomato cultivation, one of the best aquaponic systems is DUTCH BUCKET

    • In Dutch bucket aquaponic system we are using a number of buckets for growing our crops in them. In buckets, we put any growing media that is suitable for aquaponics. When we are irrigating crops the water is moving through growing medium and feeding the root of our plants.
    • We need to make sure that there is always some water in the bottom of the bucket.
    • We can achieve this by drilling drainage holes on a certain height of the bucket. For this system to work we do not need any additional siphons.
    • When constructing Dutch bucket aquaponic system pay special attention to the following
    1. Greenhouse space usage
    2. Pipes and nozzle clogging
    3. Space for roots development
    4. Bucket drainage
    • Tomatoes prefer warm temperatures with full sun exposure. Below 8-10°C, the plants stop growing, and night temperature 13-14 encourage fruit set. Temperature above 40°C cause floral abortion and poor fruit setting.
    • Tomatoes have a moderate tolerance to salinity, which makes them suitable for areas where pure freshwater is available. However, higher salinity at fruiting stage improves quality of the products.

    Planting Instructions: -

    • Set stakes or plant support structures before transplanting to prevent root damage.
    • Transplant the seedlings into units 3-6 weeks after germination when the seedling is 10-15 cm and when the night time temperatures are constantly above 10°C.
    • In transplanting the seedlings, avoid waterlogged conditions around the plant collar to reduce any risk of diseases.
    • Once the tomato plants are about 60 cm tall, start pruning the unnecessary upper branches. Remove the leaves from the bottom to 30cm of the main stem for better air circulation and reduce fungal incidence.
    • Remove the leaves covering each of the fruiting branches soon before ripening to favour nutrition flow to the fruits and to accelerate maturation.

    Harvesting: -

    • Most cherry tomato plants will start flowering in about a month. Flowers will be followed by tiny green fruits. After a few weeks, those turn into full-blown cherry tomatoes you can harvest.
    • A truly ripe cherry tomato will come off its stem very easily and is well worth waiting an extra day for, so hold off on picking them until they're ripe. Then, pluck individual fruits every day for best results. With luck, your plant will continue to produce right up until winter. If the weather turns unseasonably cool or an early frost threatens, you can tuck an old sheet over and around the plant to extend your harvest season.
    • Fruits can be easily maintained for 2-4 weeks at 5-7°C under 85-90 percentage relative humidity.

    Tips: -

    • PH: 5.5-6.5
    • Plant spacing: 40-60cm (3-5 plants/sqm)
    • Germination time and temperature: 4-6 days and 20-30 °C
    • Growth time: 50-70 days till the first harvest; fruiting 90-129 days up to 8-10 months.
    • Optimal temperature: 13-16°C night, 22-26 °C day
    • Light exposure: full sun
    • Recommended methods: Media Beds and DWC
  • Hydroponics Lettuce for profit!

    • Growing hydroponics lettuce is one of the easiest and the best ways to start hydroponic gardening.
    • Lettuce is a simple to grow all round plant that can ensure you get great results when grown in soil, as long as you keep pests off it.
    • This is where growing lettuce hydroponically will make perfect sense and will be a terrific first task for any hydroponic setup.
    • Lettuce hydroponics will typically look after themselves and do not need a lot of nutrients as other heavy feeding plants like tomatoes.
    • It's obviously still a great practice to check out your growing hydroponic lettuce plants every day for pests or other problems, though these problems are considerably decreased with hydroponics, particularly indoor hydroponics.
    • Actually, the only issue you could come across when growing hydroponic lettuce at home is size.
    • Lettuce is in high demand and has a high value in urban and peri-urban zones, which makes it a very suitable crop for large-scale commercial production.

    Note: -

    • Check lettuce for signs of downy mildew, powdery mildew or gray mold and get rid of any infected plants.
    • Water that's heavily chlorinated can lead to issues with lettuce. You should use lightly chlorinated city water or well water.

    Lettuce varieties: -

    Lettuce can be characterized based on their leaf and head formation.

    Crisp head or iceberg: -

    • Crisp head lettuce, more commonly known as iceberg, has a tight head of crisp leaves. Often found in the local salad bar, it is actually one of the most difficult lettuce varieties to grow. This lettuce variety is not fond of hot summer temperature or water stress and may rot from the inside.
    • Start iceberg lettuce via seed directly sown 18-24 inches apart or started indoors and then thinned 12-14 inches between heads. Some iceberg lettuce varieties include Ballade, Crispino, Ithaca, Legacy, Mission, Salinas, Summertime and Sun Devil, all of which mature in 70-80 days.

    Romaine or Cos: -

    • Romaine varieties are typically 8-10 inches tall and upright growing with spoon-shaped, tightly folded leaves and thick ribs. Colouration is medium green on the exterior to a greenish white inside with the outer leaves.
    • Sometimes being tough whilst the interior foliage is tender with wonderful crunch and sweetness. Different types of this lettuce are Brown Golding, Chaos Mix black, chaos Mix white, Dark green Romaine, De Morges Braun, Hyper Red Rumple, Little Leprechaun. All of which mature within around 70 days.

    Butterhead, Boston or Bibb: -

    • One of the more delicate varieties of lettuce, Butterhead is creamy to light green on the inside and loose, soft and ruffled green on the exterior. These different types of lettuce may be harvested by removing the entire head or just the outside leaves and easier to grow than crispheads, being more tolerant of conditions.
    • Less likely to bolt and rarely bitter, the butterhead lettuce varieties mature in about 55-75 days and spaced similarly to the crispheads. These varieties of lettuce include Blushed Butter Oak, Buttercrunch, Carmona, Divina, and Yugoslavian red.

    Growing Conditions: -

    • Lettuce is a winter crop. For head growth, the night air temperature should be 3-12°C, with a day temperature of 17-28°C.
    • The generative growth is affected by photoperiod and temperature extended daylight warm conditions(>18°C) at night cause bolting. Water temperature >26°C may also result in bolting and leaf bitterness.
    • The plant has low nutrient demand; however higher calcium concentrations in water help to prevent tip burn in leaf in summer crops.
    • The ideal PH is 5.8-6.2. but lettuce still grows well with a PH as high as 7, although some iron deficiencies might appear owing to reduced bio-availability of this nutrient above neutrality.

    Growing instructions:

    • Seedlings can be transplanted in units at three weeks when plants have at least 2-3 true leaves. Supplemental fertilization with phosphorous to the seedlings in the second and third weeks favours root growth and avoids plant stress at transplant.
    • Take care not to damage the roots of plants during transplanting because such damage will make the plant susceptible to disease infection.
    • It is advisable to transplant the plant in the late afternoon to prevent them becoming stressed in the heat of the day under high UV conditions.
    • The transplant will begin to adapt to the new location at night and roots will start to grow into the solution below.
    • Make sure the plants base is touching the flow of nutrient solution below when transplanting.
    • To achieve crisp sweet lettuce, grow plants at a fast pace by maintaining high nitrate levels in the unit. When air and water temperatures increase during the season, use bolt -resistant(summer) varieties. If growing in media beds, plant new lettuces where they will be partially shaded by taller nearby plants.

    Lighting: -    

    • Lettuce grows up vigorously with fluorescent lighting. It would obviously grow far better with the more expensive lighting specially created for hydroponics, like HID and some of the latest LED grow lights for indoor plants.
    • However, regarding cost-effectiveness, from the viewpoint of the small-scale grower, fluorescent lighting is the best.
    • These are cool weather crops, so too much heat can, in fact, delay germination.

    Harvesting Hydroponics lettuce: -

    Hydroponics harvesting depends on the following factors

    • First, this will depend on what type you are growing. Romaine takes up to 85 days. Bibb and Loose-leaf lettuce can take 45 to 55 days.
    • It has to do preference, growing lettuce indoors then you have to manage the environment and prolong your harvest.
    • The majority of hydroponic lettuce production systems created around two ideas, either the floating raft system or the nutrient flow technique (NFT) system.
    • The floating raft method is of particular interest since it is very affordable and can produce a lot of hydroponic lettuce.
    • One of the major issues with raft systems is that the hydroponic lettuce nutrients solution is continually stagnant and will require that you use pumps to circulate water and produce important aeration.
    • If the roots are not getting the precious oxygen, floating raft systems experience substantial loses of crops in the form of nutrients.

    Below are some types that work well in hydroponics and with indoor artificial lighting:

    • Royal Oakleaf is a darker green variety of lettuce that does extremely well in hydroponic growing systems and is also resistant to heat.
    • Tango grows perfectly in cooler environmental only.
    • Red Fire is a deep red, loose leaf variety that's ideal for both warm and cool climates.
    • Green Ice is a variety of green loose that offers a long picking season.

    Hydroponic romaine lettuce also does well though it usually takes a little bit longer to attain maturity.

    Tips: -

    • When you harvest lettuce with the roots attached, it will prolong storage life by two to four weeks.
    • To prevent getting water mold such as Pythium or Phytophthora in your hydroponic lettuce system, use bleach to sanitize the tray between plants. If the lettuce gets infected, the plant is a loss.
  • Catch the right fish!

    Aquaponics is an amazing way to garden. And workhorses of an aquaponic system are the aquaponic fish. Aquaponics is a natural process whereby fish are raised in an aquarium or large size fish tanks and their waste is pumped into grow beds. Waste is then naturally converted into nutrients for the plant's roots to absorb within a grow medium. Plants, in turn, clean the water in this recirculating and symbiotic system.

    Before we can grow our plants, we must first choose the correct aquaponics fish. Not all aquaponic fish are equal or have the same requirements for survival. Therefore, let's review some key considerations before choosing the best aquaponics fish for our needs.

    Considerations for choosing aquaponics fish: -

    Ornamental vs Edible: - While there are many aquaponics fish which do well in aquaponics systems, not all are edible. For example, goldfish and koi are great ornamental aquaponics fish just don't eat them!

    Temperature: -

    Some aquaponics fish thrive in cold water, while others do well only in warm water. Be sure we choose a species of fish that is hardy and adaptable for our particular indoor or outdoor conditions. Adding water heaters to


    the system is an option.

    Purchasing your Aquaponics fish: - Choose a species which is readily available to buy as a fingerling or juvenile fish. Selecting a suitable adult fish is also a possibility.

    Breeding: -If you want to produce your own stock, select a species that is capable of breeding within an enclosed aquaponics tank. However, understand the government regulations for the same.

    Popular Aquaponics Fish: -

    Here are the best aquaponics fishes, we have included an ideal temperature range for each species. Please note that while most fish are able to tolerate varying degrees of the temperature outside of the ideal range, we recommended you keep your aquaponics fish within these parameters as much as possible

    Tilapia: -

    • Tilapias are one of the most popular freshwater species to grow in aquaponic systems.
    • Why? For starters, tilapia is a great eating fish. It has a mild flavour, making it adaptable to many culinary styles. Tilapia is also a great fish for aquaponics beginners. They adapt to their environment and are able to withstand less than ideal water conditions. Other benefits of choosing tilapia include their fast growth rate (about 9 months from fingerling to harvest), ability to reproduce easily, and have an omnivorous diet.
    • One drawback to raising tilapia is the need to keep your aquaponics tank warm. Water below 55 degrees will cause tilapia to struggle. A constant water temperature of around 80 degrees is ideal. Adding a water heater is a viable option if water temperatures are fall low during winters, or you may consider choosing a different aquaponics fish altogether. Another possible drawback is their ability to breed quickly (every 4-6 weeks). If you have a small aquaponics system, be advised that it may quickly fill with young fish.

    Key Considerations: -

    1. Ideal Temperature Range: 72 - 86° F
    2. Popular, edible, warm-water aquaponics fish
    3. Easy to breeding and fast growing.

    Trout: -

    Looking for an aquaponics fish that thrives in cooler water? Trout may fit the bill. They thrive in temperatures ranging in the 50s and 60s. making them ideal for cool environments. This species of fish has a high food conversion ratio and grow quickly, although it may take up to 16 months to fully mature. In addition, trout are a desirable food source, loaded with protein and omega fatty acids.

    • Because trout thrive in cold water, some aquaponics enthusiasts alternate between raising tilapia during warmer months and trout during cooler months. Trout is also a popular aquaponics fish to raise in indoor garages and basements.
    • It should be noted that trout are not as adaptable as some other fish, as they require pristine water and high dissolved oxygen levels to thrive. Close monitoring of "PH" levels is also important. Another possible downside is fewer plants choices. Because recirculating cold water may harm certain plants, be sure to pick hardier plants varieties. With that said raising trout may be too much effort for some, but the payoff at the dinner table makes this species a popular aquaponics fish.

    Key Considerations: -

    • Ideal Temperature Range: 56 -  68° F
    • Edible cold-water fish
    • Requires pristine water, high dissolved oxygen levels, and close pH monitoring

    Catfish: -   

    • Catfish are a popular bottom-feeding aquaponics fish. They vary in size and are often commercially farmed for their flavour and high vitamin D content. Another advantage to choosing catfish is their high food conversion ratio, meaning they convert their food to body mass quickly.
    • Raising catfish requires close monitoring of the aquaponics system. Water must remain pristine, temperatures must remain close to 80 degrees, and PH should be kept in check. Catfish feed on a variety of plants, bugs small fish, and pellets. They do not have scales, so skinning is required before putting catfish on the frypan.

    Key considerations: -

    • Ideal Temperature Range:  78 - 86° F
    • Edible, popular aquaponics fish
    • High food conversion ratio makes them a fast-growing fish
    • Sensitive to water temperature,water quality, and pH

    Perch: -

    Silver, Yellow, and Jade varieties of perch are popular aquaponics fish. Because they are adaptable to various conditions, perch make a good starter fish for beginners. Perch typically thrive in water temperatures ranging in the 70's. However, they are able to withstand colder water down to the 50's.

    • The diet of perch is primarily carnivorous, consisting of small fish, bugs, and shrimp. This may turn some off to raising perch because carnivorous diets involve more expense and effort (compared to fish who simply consume pellets and plant matter). Another factor to consider is the longer time frame to mature. Silver perch, for example, may take up to 16 months to fully mature from the fingerling stage.  Overall, perch are a good choice for those looking for a tasty aquaponics fish and have the patience to wait for them to develop and the budget to feed them their preferred diet.

    Key considerations: -

    • Ideal Temperature Range: 70 - 82° F
    • Edible, hardy, adaptable aquaponics fish
    • Slower to mature and carnivorous diet

    Barramundi: - 

    • Barramundi is one of the most popular fish raised in aquaculture. They also make a great aquaponics fish and can be kept in both fresh and saltwater systems. As an edible aquaponics fish, barramundi has flaky white flesh and are regarded as a good species for eating.
    • Larger barramundi is known to attack smaller ones, so it is advised to keep these fish separated by size or risk young being injured or eaten. Many aquaponics hobbyists purchase larger juvenile fish instead of fingerlings. This cuts down the likelihood of losing fish to aggression. Barramundi also requires pristine water conditions and high dissolved oxygen levels.

    Key considerations: -

    • Ideal Temperature Range:  78 -  83° F
    • Edible aquaponics fish, popular in commercial aquaculture
    • High food conversion ratio
    • Aggressive tendencies towards smaller fish

    Bass: -

    • Large mouth, small mouth, and striped bass are another top aquaponics fish. However, this species is less adaptable to unfavorable conditions compared to others. Conditions must be monitored to ensure pristine water, and proper oxygen and PH levels. In addition, bass will not tolerate bright light or a poor feeding regime. Another downside is the long wait period to mature. Large mouth bass can take up to 18 months to reach its full size. Striped bass typically mature faster.
    • The upside to using bass as young aquaponics fish is that they are edible and fairly easy to acquire locally. Young fingerings can be trained to feed on pellet food but are generally carnivorous.
    • If you don't mind the daily monitoring of your aquaponics system, bass is a viable and rewarding aquaponics fish.

    Key considerations: -

    • Ideal Temperature Range: 75 - 85° F
    • Edible and accessible aquaponics fish
    • Requires constant monitoring to ensure proper conditions

    Koi Fish: -

    • One of the most popular ornamental fish is Koi. They are often found in decorative ponds. Like goldfish, koi produce a lot of waste matter and are easy to find at pet stores. This makes koi a popular aquaponics fish.
    • Koi are prized for their beauty and bright coloration. Surprisingly, koi are considered an edible aquaponics fish. However, we don't recommend eating them. Most hobbyist raise koi strictly for ornamental purpose.
    • Other advantage of koi includes their resistance to parasites, long life-span, and their simple omnivorous diet. A key disadvantage is the cost to purchase koi. While they are fairly easy to find at pet stores, koi tend to be more expensive than most aquaponics fish. Koi can live up to an astounding 40-60 year.

    Key considerations: -

    • Ideal Temperature Range:  65 - 75° F
    • Ornamental, not typically eaten
    • Ornamental, hardy, and attractive aquaponics fish
    • Omnivorous, parasite-resistant, and lives a long time

     Gold Fish: -

    • Goldfish are one of the earliest species of the fish to be domesticated and among the most popular fish used in aquaponics today. They are attractive in appearance and are readily available at local pet shops. Generally speaking, these miniaturized carp species are hardy and adaptable to various water conditions.
    • They prefer a temperature in the 60s - 70s degree range. Goldfish are especially well-suited for smaller aquaponics systems but can thrive in an aquaponics system of any size.
    • Goldfish are known as a shy fish, Because of this quirkiness, they require plant cover to breed. For such a small species, goldfish produce lots of beneficial waste nutrients for aquaponics grow beds to absorb. Due to this small size and susceptibility to parasitic issues, goldfish are not considered edible fish.

    Key considerations: -

    • Ideal Temperature Range:  68 - 75° F
    • Ornamental, not typically eaten
    • Small, hardy aquaponics fish
    • Produces lots of waste despite its size
  • Grow the best Hydroponic Broccoli

    Broccoli is a nutritious winter vegetable and very well suited to grow in hydroponics. It can be started from seeds or plants.

    Media bed method is recommended because Broccoli grows into a large and heavy plant by harvest. Growing broccoli is moderately difficult because it is high nutrient demanding plant and also susceptible to warm temperature.








    Growing Conditions: -

    Broccoli grows best when the daytime temperature is at 14-17 °C. For head formation, winter varieties require a temperature of 10-15 °C. Hot temperatures cause premature bolting.

    Growing Instructions: -

    Transplant the seedlings into media beds once it has 4-5 true leaves. And seedlings should be positioned 450 cm apart as closer spacing will produce smaller central heads. Broccoli, like cabbage, is susceptible to cabbage worms and other persistent pests.

    Pests/Diseases: -

    • Aphids: Curling leaves may mean that the plant's sap is being sucked by insects. Apply soapy water to all sides of leaves whenever you see aphids.
    • Downy mildew: Yellow patches on leaves are usually caused by moist weather. Keep leaves as dry as possible with good air circulation. Buy resistant varieties.
    • Cabbage loopers: Small holes on the leaves between the veins might be because of green caterpillars. Look at the undersides of the leaves. Hand pick if the problem is small or control with Bacillus thuringiensis, a natural, bacterial pesticide.
    • Cabbageworms and other worm pests: Treat same as loopers.
    • Cabbage Root Maggots
    • Whiteflies
    • Nitrogen deficiency: If the bottom leaves turn yellow and the problem continues toward the top of the plant, the plants need a high nitrogen (but low phosphorus) fertilizer or blood meal. Blood meal is a quick nitrogen fix for yellowing leaves.
    • Clubroot: Quickly wilting plants may be due to this fungus. The entire plant, including all roots and root tendrils, must be gently dug up and removed. If the roots are gnarled and misshapen, then clubroot is the problem. Act quickly to remove the plants so that the fungus doesn't continue to live.

    Harvesting: -

    • In terms of timing: Harvest broccoli when the buds of the head are firm and tight before the heads flower. If you do see yellow petals, harvest immediately.
    • For best taste, harvest in the morning.
    • Cut heads from the plant, taking at least 6 inches of stem.
    • Cut the stalk of the main head at a slant, about 5 to 8 inches below the head.
    • Most varieties have side-shoots that will continue to develop after the main head is harvested. You can harvest from one plant for many weeks, in some cases, from winter to beginning of summer, if your summer isn’t too hot.
    • Store broccoli in the refrigerator for up to 5 days. If you wash before storing, make sure to dry it thoroughly.
    • Broccoli can be blanched and frozen for up to one year.

    Parameters for good yields: -

    PH: 6-7

    PPM: 1960-2450

    EC: 2.8-3.5

    Plant Spacing: 40-70 cm (3-5 plants/sqm)

    Germination time and temperature: 4-6 days with a temperature of 25°C

    Growth time: 60-100 days from transplant

    Average daily temperature: 13-18°C

    Light exposure: full sun; can tolerate partial shade but will mature slowly.

    Recommended method: Media bed

  • Understanding PH Control

    What is pH?

    pH is a measure of the relative concentration of hydrogen ions (H+) to hydroxide ions (OH-). The greater the number of H+ ions in relation to OH- the more acidic the solution becomes. The greater the ratio of OH- ions to H+, the more basic the solution becomes. PH is measured on a scale of 1-14. A reading below 7 means that there are more H+ ions and a reading above 7 indicates more OH- ions. At pH 7 there are the same number of H+ ions as OH- ions so the pH is neutral, neither acid nor base.










    Acids and Bases

    Any substance that increases the concentration of hydrogen ions (lowers the pH) when added to water is called an acid. A substance that reduces the concentration of hydrogen ions (raises the pH) when added to water is called a base or an alkali. Some substances enable solutions to resist pH changes when an acid or base is added. These substances are called buffers. Buffers are very important in helping to maintain a relatively constant pH in a feeding solution and in the root zone after the water has been applied to the crop. Most greenhouse water supplies have sufficient alkalinity that they require routine acid addition to correct the pH to the normal 5.8-6.2 feeding range. At this level, the irrigation water tends to have a neutral effect on media pH, although this depends on the buffering capacity of the media. Some growers use very pure water from rain and surface sources. In these situations, they may need to apply a combination of acid and base materials to stabilize and buffer the pH.

    Why does pH Matter?

    Improper management of media pH can result in poor growth and reduced plant quality in greenhouses and nurseries. The pH or soil reaction has a primary influence on the solubility and availability of plant nutrients. Many crops have a narrow range of pH tolerance. If the pH of the soil medium falls above or below this tolerance zone, they may not grow properly due to nutrient deficiency or toxicity.

    The availability of most fertilizer elements is affected to some extent by the media pH. Calcium and magnesium become more available as the pH increases, while iron, manganese, and phosphorus become less available. A one-unit pH drop can increase the solubility of manganese by as much as 100 times, and the solubility of iron by as much as 1000 times.

    Why Adjust Irrigation pH?

    By carefully modifying the pH and alkalinity of your irrigation and feed solutions, you can help maintain the desired plant growth and quality. There are other reasons to monitor and control pH in your irrigation water and nutrient solutions: 1) Solution pH affects the availability of nutrients. 2) Correct pH helps ensure dissolved fertilizer concentrates remain in solution when mixed in the water supply. 3) Acid injection can be used to neutralize excess alkalinity in water supplies.

    Understanding The pH Scale

    The pH scale measures the relative concentration of Hydrogen Ions (H+) and Hydroxyl ions (OH-) in a solution. Technically, the pH of a solution is defined as a negative logarithm of the hydrogen ion concentration. The "P" is the mathematical symbol for a negative logarithm and the "H" is the symbol for hydrogen. The pH scale measures this, and places a value on it ranging from 0 to 14. Since it is a log scale, each number on the scale is 10 times greater (or smaller) than the next. A lower pH number corresponds to a higher concentration of hydrogen ions (H+) relative to hydroxyl ions (OH-). A higher pH number corresponds to a relatively lower concentration of hydrogen ions

    Measuring pH

    There are several methods available for measuring pH, but the most useful and practical is an accurate pH meter. Follow the instructions included to preserve the accuracy and life of your instrument. These meters typically use a liquid filled glass probe, although some are now using flat sensor technology.

    Water and nutrient solution samples can be measured directly or preferably after a few hours of settling time. Dissolved CO2 in water supplies can cause slightly lower readings until the sample has come to equilibrium with the air. When testing media, freshly mixed samples of media should be watered and allowed to stand for 24 hours before a reading is taken to release some of the lime and fertilizers. The preferred method for testing media pH is to obtain several representative samples of a crop and to measure each separately. Multiple measurements give greater accuracy in reading, and shows the degree of variability of pH across several locations. A saturated media extract or a 1:1 soil to distilled water ratio is fine for measuring media pH.

    Factors Affecting pH

    These variables can affect the final pH, the rate of pH change, and the amount of modifying action required. They include the effects of:

    • Soil temperature
    • Fertilizer materials (may raise, lower or buffer pH)
    • Soil amendments such as gypsum, sulfur and lime
    • Root volume & metabolic activity
    • Soil microorganisms
    • pH and alkalinity of the irrigation water
    • Leaching fraction
    • Buffering capacity of both the soil medium and the irrigation source
    • Media cation exchange capacity
  • Know your water

    Know your water to know your best water soluble fertilizer options.

    Water quality is the single most important factor in determining solubility and nutrient availability for plants. It's especially important that you test for the key parameters like pH, TDS and EC if you have one of the following factors:

    •  Borewell water
    • Change in irrigation water source
    •  Multiple sources of irrigation water
    •  Recent flooding or droughts

    The primary considerations when formulating and evaluating your plant nutrition program are:

    1. Nutritional content of the water
    2. Its effect on growing media pH
    3. Its content of potentially toxic components

    With today's soilless growing media, water's alkalinity is the main area of focus. Alkalinity is a measure of how much buffering the water will provide to the given growing media.
    If alkalinity is too low, the growing media pH can plunge due to acidic influences like fertilizer, growing media components and plant root exudates. If this happens micronutrient toxicities can occur. Conversely, if alkalinity is too high, growing media pH can soar, leading to deficiencies in micronutrients, such as iron. In this case, you may be applying plenty of iron, but it becomes unavailable to the plant at higher growing media pH.
    A thorough water analysis will measure the alkalinity of your irrigation water as well as many other elements. Having your water tested can make the difference between growing a good crop and growing a great crop!

    The four main water types:

    While it's important to get complete water analysis of your irrigation supply, you can base your fertilizer choices on your water type category and the plants you're growing.

  • Calcium - An essential plant nutrient

    With all of the emphasis on N-P-K in agriculture, calcium and magnesium are sometimes overlooked. Calcium and magnesium are essential macro-elements, used in relatively large quantities. In fact, plants take up more calcium than phosphorus!


    • Calcium is much needed in plant growth for below reasons:
    • Participates in metabolic processes of other nutrients uptake.
    • Promotes proper plant cell elongation.
    • Calcium is required for the stability and function of cell membranes and acts as a type of `cementing agent ' in the cell walls in the form of `calcium pectate'.
    • Participates in enzymatic and hormonal processes.
    • Helps in protecting the plant against heat stress - calcium improves stomata function and participates in the induction of heat shock proteins.
    • Helps in protecting the plant against diseases - numerous fungi and bacteria secret enzymes which impair plant cell wall. Stronger Cell walls, induced by calcium, can avoid the invasion.
    • Affects fruit quality.
    • Has a role in the regulation of the stomata.


    In hydroponic systems, adequate levels of calcium are usually maintained with calcium nitrate or other calcium salts. Therefore the lowering of calcium levels in the plant tissue and the occurrence of deficiency symptoms usually result from the influence of other factors which impede either calcium uptake or its distribution within the plant. Calcium uptake may be reduced by the competitive effects of a high concentration of other cations such a potassium, sodium, magnesium or ammonium in the solution. And since calcium moves in the xylem tissue, its uptake is also affected by low root temperature and by restricted water movement through the plant caused by high salinity in the media or excessive humidity in the atmosphere.

    Higher EC levels in the nutrient solution reduce the uptake of calcium, unlike nitrogen and potassium which increase in concentration in leaf tissue with higher EC levels. Reducing the EC of the nutrient enhances water uptake and with this, more calcium can be taken up and transported within the plant to developing tissue.


    • Calcium deficiency results in marginal yellowing, tiny and deformed leaflets, curled up margins in Tomatoes.
    • White spots form on edges and veins of upper leaves in Cucumbers.
    • Growing point region of youngest leaves remains small, later the leaves shrivel and growing point dies.
    • Blossom end rot is observed in tomatoes while Cucumber buds might abort and finally, plant dies back from the apex.


    The simplest means of preventing calcium deficiency disorders such as tipburn and blossom end rot is to maintain adequate calcium levels in a balanced nutritional solution with the correct EC level. Use 0.75% - 1.0% calcium nitrate solution as foliar spray in acute cases. As always, moderation is always recommended when using additives. Start with very low dosages, see how the plants respond and add more if necessary. Keeping the plants stress free, providing gentle air movement across the leaf source to encourage transpiration and preventing excessive temperatures all help drive calcium into leaf tips and developing fruits.

  • Food Security & Sustainable Farming methods

    The increase in population and urbanization has resulted in increased need for food and water in India. Our lands have become water and nutrient scarce and continuous use of synthetic fertilisers has depleted soil diversity which is needed for crop production. Challenges such as soil-borne diseases, weeds, and soil infertility, associated with soil plant production have made the soil culture risky and at times undesirable. As a result of the need to produce more and good quality food, without further damage to the natural environment, there has been an exploration of soilless agricultural systems, most popular, these include aquaculture, hydroponic and recently aquaponics system.

    Overview of Soilless Systems

    In soilless production, plants are raised without using soil as a growth medium. The method of not using soil as a crop stand saves significant water because in soil systems water can leach into groundwater. There are various common and available soilless productions systems; these systems include hydroponic, aeroponics, aquaponics, vertical gardens and tunnel or greenhouse aquaculture culture. Soilless production plays a critical and unique role in providing out of season food (meat and crop plants), herbs and flowers. While soilless systems have been a viable option to food and nutrition security in many countries there is little known or documented about these systems.


    Hydroponics or hydroponic culture is a system where plants are grown in a soilless growth medium where all mineral nutrients delivered to plants are first dissolved in water before nutrients are available to plants. There are two types of hydroponic systems that are usually in use, these are liquid and aggregate production systems. The liquid hydroponic culture usually adopts nutrient film technique, and Deep-Water Culture (DWC)/floating rafts system. The growth medium hydroponic systems adopt various inert materials such as gravel, perlite, peat moss, peat, sawdust, rock wool, coconut fibre, grow stones, oasis cubes, vermiculite, coarse sand and expanded clay pellets.


    Aquaponics is a bio-integrated system that links recirculating aquaculture with hydroponic vegetable, flower, herb production, in the process saving a significant quantity of water. In an aquaponics system, effluent that is generated from the fish tanks is pumped and used in fertigation of growth medium beds (GMB) in hydroponic culture. In return, this process is worthy to the fish, because crop plants roots system together with rhizobacteria helps to extract available nutrients from water solution. The nutrients materials produced from fish algae, manure, and decomposing uneaten fish feed are pollutants that could build up to lethal levels in fish tanks, however, this instead waste serve as liquid mineral fertilizer in hydroponic culture. The hydroponic culture function as a biofilter removing off ammonia, nitrates, nitrites, and phosphorus and other trace elements, so the freshly cleansed water can then be recirculated back into the fish tanks. The nitrifying bacteria living in the gravel and in association with the plant roots play a crucial role in nutrient cycling. In the absence of these microorganisms, the whole system would be dysfunctional.

    Role of Hydroponics & Aquaponics in Food Security

    Food security exists when all people, at all times, have physical and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life. There are four food security pillars which define, defend and measure food security status locally, nationally and internationally. These are food availability, food accessibility, food utilization and food stability.

    On top of food and nutrition security agenda/resolution is to achieve a method or programme that can directly support people with the opportunity to realize food security, particularly nutrition security. Developing simplified Hydroponics systems to make nutritious food production achievable for one and all is the core mission of Hydrilla Urban farms.

  • Welcome

    Welcome to Hydrilla.....

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