A Plant Fertilizer Recipe for the Control of Algae in Planted Aquaria

This method of fertilizing the water column in planted aquaria uses phosphate as the limiting plant growth factor. In this method, larger order plants are able to out-compete algae for this limited resource and thus control the appearance of algae. Use of this method entails regular (possibly daily) dosing of small amounts of fertilizer to ensure an abundance of nutrients and a limited supply of phosphate. Simply put, if you see algae, you are using too much fertilizer. If your plants are going yellow, you are using too little fertilizer. Use common fertilizer tests for nitrogen to gain an accurate level of nutrients within the water column. There is a possibility that micronutrients can become toxic if a 25% water change is not done every second week.

There are main micronutrients. They include Boron, Calcium, Chloride, Copper, Iron, Magnesium, Manganese, Molybdenum, Sulfur, Zinc. These nutrients are often found in small amounts in tap water, and in low growth conditions, it isn’t necessary to supplement them. But with improved plant growth, these nutrients will be quickly depleted from the water, and plants will suffer. For the Micronutrients, there are many commercially available fertilizers. The micronutrient mix provided by Homegrown Hydroponics Inc. contains iron, manganese, magnesium, sulfur, boron, zinc, and molybdenum. Alternatively, many people make their own.

Mix with water to make a 1500 ml solution,

(Six Pack # 2)      2 Teaspoons (14g) K2SO4 (potassium sulfate)
(Six Pack #3)       1 Teaspoon (6g) KNO3 (potassium nitrate)
(Six Pack #5)       2.5 Tablespoons (33g) MgSO4
(Six Pack #6)       1 Tablespoon (9g) Chelated Trace Element Mix (7% Fe, 1.3% B, 2% Mn, 0.06% Mo, 0.4% Zn, 0.1% Cu, EDTA, DTPA)
300 ml (1.5 cups) distilled H2O


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