Richard bray

Aphids are small, light green bugs that feed on sap. Aphids will crowd around a leaf or flower base and leave a sticky residue.
Caterpillars are easy to identify on plants, and they can do massive damage in a short amount of time. Large holes in leaves are the classic indicator of caterpillars.
Mealy bugs are white, fuzzy, sticky insects that feed on the sap left behind by aphids. If an aphid infestation goes unchecked, a mealy bug infestation is sure to follow. Avoid mealy bugs by avoiding aphids, and destroy any infested plants before it can spread to your entire crop.
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Disease
Aquaponic plants are highly susceptible to rot, fungus, and mildew. These systems keep plants wet constantly, and also create a microclimate of high humidity, which encourages these diseases.
It is impossible to find a spray for these diseases that is harmless for fish. The most common cause of rot, fungus, and mildew is lack of ventilation and poor water circulation and quality. If you see signs of disease, do a water test and check your solids filter. If your water is sludgy, disease will follow.
Destroy any plants that show signs of disease, clean out your solids filter, and increase aeration. If you have media-filled beds, add red wiggler worms to your grow beds. Warm water temperatures can increase the risk of disease, so try to keep your water on the cooler end of what the fish will tolerate.
You may also have to drain off 1/3 of your system water and replace it with fresh water. Clean, balanced systems should not have a major issue with disease.
Failure to Fruit
This is a frustrating dilemma. Often, fruiting vegetables are beautiful, lush, and green. They simply refuse to flower or fruit.
This is generally caused by too much nitrogen. Nitrogen encourages leafy green growth, but too much will cause plants to focus on leaves instead of fruit. Try to reduce the amount of fish feed to lower nitrogen levels.
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If your plants are indoors, they may not be getting the right light for fruiting. Grow lights with more blue wavelengths will encourage leaf growth, while grow lights with more red wavelengths will encourage flowers and fruit. If you are switching from leafy crops to fruiting crops, consider switching your grow lights for proper fruit set.
Dirty Water
If the water in your system is dirty, this can lead to disease for your plants and fish. Clean water is essential for a healthy system.
A properly-functioning solids filter is vital for clean water. Clean out your solids filter on a weekly basis until the water clears up. If you are using media-filled beds, consider adding red wiggler worms to help break down the solids in the sludge layer of your grow beds.
Warm temperatures combined with high nitrogen can result in an algae bloom. If your system has an algae bloom, it can clog pipes, restrict water movement, and absorb the nutrients intended for your crops.
If you notice algae in your system, try to limit the amount of light that reaches the water. Cover your fish tank and make sure your rafts reach the edges of your grow beds. Lower the temperature of your water (if possible) as far as you can while remaining within the healthy range for your fish.
If your water is still murky, try draining off 1/3 of the system water and replacing it with fresh water.
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