It's just pool filter sand. Tank has been running for about 8 months now, so the substrate should have some amount of nutrients. I dose Flourish weekly and daily liq. CO2. I do have some algae which I don't mind too much since it's food for my 5 otos. I have considered increasing my photoperiod though by an hour.
Flourish is only macro nutrients I believe right? you need micros as well. While the algae isn't bad for the ottos, its going to be horrible for the plants, and increasing the light period now I think wouldn't help that.
Look into more balanced dosing and getting root tabs...they will help your swords and hairgrass
