This system kit includes:
- 1 litre of Potassium Hydroxide (adjusts pH up)
- 1 kg of Calcium Hydroxide (adjusts pH up)
- 1 litre of Phosphoric Acid (adjusts pH down, very strong use small amounts)
- 350 g of Chelated Iron (DTPA) 7% for addressing iron deficiencies
- 200 g of Rock Phosphate (for addressing phosphorus deficiencies, stimulating root growth in seedlings, promoting fruiting)
- 200 g of magnesium sulphate for addressing magnesium deficiencies
- API Freshwater Master Test Kit for testing your water quality
Maintaining an Aquaponic System
Fish feed and consequently fish waste supplies most of the nutrients required by plants in adequate quantities. There are some deficiencies however that often must be addressed by adding supplements. Here is a table of the nutrients required by plants:
MOST SYSTEMS REQUIRE CALCIUM, POTASSIUM AND IRON SUPPLEMENT
The 3 nutrients that must usually be added are Potassium, Calcium and Iron. Sometimes a little Magnesium and Phosphorus are also required. Since the pH in a well functioning system should always drop over time (due to the nitrification of ammonia), the best way to adjust the pH and add nutrients at the same time is to alternate between Potassium Hydroxide
and Calcium Hydroxide
. This will give you a balanced amount of Calcium and Potassium.
If you need to lower your pH, use phosphoric acid
since your plants can also make use of the phosphorus. You will likely need to supplement phosphorous only for fruiting and flowering nutrient hogs such as tomatoes or cucumbers. If you need to add phosphorous without adjusting pH use rock phosphate
HOW TO SPOT DEFICIENCIES
- Nitrogen: Starts with older leaves becoming more yellow than the younger ones. Entire plant starts to turn yellowish.
- Calcium: Newer leaves show distorted growth. Mild deficiency can result in cupped or curled leaves and moderate deficiency can result in twisted leaves that look like they're squished.
- Potassium: Older leaves start to have small dead areas that start like little pinpoints and grow. Yellow areas can appear which then wither at the edges and tips
- Iron: Newer leaves show reduced chlorophyll. Leaves turn yellow with greenish nerves enclosing yellow leaf tissue. It's first seen in fast growing plants.
- Phosphorus: Plants stop growing and become darker green (some species become purple). Premature leave drop-off. Fruiting plants such as tomatoes are not producing.
- Magnesium: Older leaves start to yellow from the edges inward. The midrib may remain green while edges are yellowed or whitish. (If you need to add magnesium you can use epsom salt)
|Graphic From GrowREALFood.com
PH AFFECTS NUTRIENT CONCENTRATIONS
Be aware that the pH levels in your system will affect the nutrient availability in your system. Try to keep your system between 6.5 and 6.8 pH.