Everything I read about fertilizers says something along the lines of "this only applies to high tech plants with high light and CO2" and that it would be a waste to dose in low tech tanks. My tank is a 90 gallon community tank with 4 32w T8 lights with a dirt substrate. All of my plants have been growing great up until recently. I think the problem was a mix of my light bulbs going bad and the dirt is running out of nutrients. My nitrates have been 0 for a few months but I am not exactly sure when that happened. I believe the lack of nitrates is what caused a BGA outbreak in the tank.
Is it true that without CO2, fertilizers are pointless? I consider the tank to be in the middle between high and low light. It seems to be just enough light not to cause too much algae and still grow plants well. Downoi was even doing great until the lights went bad. Then they started growing tall and thin.
For a tank like this what kind of dosing regiment should I follow? Should I just dose enough KNO3 to keep nitrates above 0?