DIY: Aquarium Plant Fertilizer

By Juniper Russo

Aquarium plant fertilizer can help to encourage fast cycling and plant growth, while minimizing plant die-off, nitrate buildup and algae blooms. Homemade fertilizers for aquarium plants are simple and inexpensive to create; they can help to maintain the vitality of a complete aquatic ecosystem.

Biological Fertilizers

Aquarists can create natural fertilizers using the aquarium's natural ecology. A biologically active filter is the heart of a planted aquarium. Well-designed filters containing activated charcoal can eventually create colonies of "good" bacteria, which work in symbiosis with plants and fish to purify water. In an aquarium with biologically active filtration, fertilizers develop naturally. Additionally, live fish and invertebrates naturally fertilize plants with through respiration and defecation.

Homemade Fertilizing Powders

A powder-based homemade aquarium plant fertilizer can be made using a 3:3:2:1 ratio of Epsom salt, potassium sulfate and salt peter. The plant fertilizer should be added to the aquarium in small amounts. One teaspoon per 10 gallons of water is an ideal initial dose. During water changes, equally small amounts of the fertilizer can be added to replenish nutrient and mineral levels in the water.

Trace Minerals

Trace minerals, including iron and zinc, can help aquarium plants thrive. Specialized aquarium gravel is available to provide these essential plant nutrients, but some advanced aquarists choose to use iron-rich (red) clay instead. Clay should be boiled prior to use to help eliminate unwanted organisms. It can then be placed under the aquarium gravel to enhance the water chemistry.