Aquatic Plant Fertilizer

For high-light tanks, add 1 tsp per 10 gallons 1-2 times a week; for low-light tanks, 2-4 times a month. Add it near a high-flow area like the filter outflow so it mixes through the water. Bright light drives faster growth and faster nutrient use, so well-lit setups need more frequent dosing, while low-light tanks need much less. Always dose to the actual water volume, accounting for substrate and hardscape that displace water.

At 1 tsp per quart, the 8 oz bottle makes about 48 watering cans of feed. For a typical shelf of 10–15 plants fed every 1–2 weeks in season, that's several months of feeding — and the 32 oz bottle four times that.

It's a plant fertilizer formulated for the low nutrient levels aquatic plants need, so at the labeled rate it's intended to be used alongside livestock. Stick to the dose and avoid spikes, which stress any closed system. One note for shrimp and snail keepers: it contains copper at trace levels, and some invertebrates are copper-sensitive, so introduce it gradually and watch your animals. Dose to water volume and never pour it directly onto livestock.

Overdosing can, since algae use the same nutrients as plants — but algae in a planted setup is usually driven by a light-and-CO2 imbalance more than by fertilizer alone. Too much light without enough nutrients or CO2 for plants to use it is the classic trigger. This low-concentration blend feeds plants without loading the water, but real algae control comes from balancing light, CO2, and nutrients together, plus regular water changes and not overdosing.

No — this works in both low-tech tanks without added CO2 and high-tech tanks with it. In a low-light, no-CO2 setup, plants grow slowly and need only occasional dosing, covered by the 2-4 times a month schedule. In a high-light tank with CO2, growth is fast and nutrients deplete quickly, so you dose more often. CO2 accelerates growth but isn't required; match your dosing frequency to the tank's light level and how fast the plants are actually growing.

In a well-lit tank, aquatic plants respond over a few weeks with stronger new growth and better color as they take up iron and potassium. Fast-growing stem plants show it first; slower rosette plants and carpets take longer. Existing damaged leaves won't recover, so you're feeding new growth. Because results depend as much on light and CO2 as on nutrients, a balanced tank shows the clearest improvement.