It's the water lettuce lol it grows so fast its hogging nutrients from the other plants lolThey're so active, I thought there were more of both Your tank doesn't look like you had to tear it down much to catch the tetras, good show!
I'm must be the worst fertilizer ever. I never see more than 5ppm nitrate in my "heavily fed" tank. Too many plants, light fish feeding. I do better with root tabs...& not much testing, lol
But I also pay attention to signs of deficiencies and check if it's a nitrate thing and boost my dosing as needed. Some tanks I have I don't need as much dosing, some I avoid dosing often if they have 10-20 nitrates already. But I got a couple tanks with 0-5 nitrates that need frequent dosing to keep some of the slower growing plants happier to compete with some of my other plants. It's been working for me, just watch certain plants like my pennywort in this tank. Good indicator plant if things need a boost. If nitrate deficient, it gets yellowed leaves.
The stock is surprisingly light, despite the numbers. The cories are large, but low bioload. And the boraras and tetras all super tiny.
Even with 2x daily feedings on this tank, nitrates stay super low, if any at all.
I run a DIY sump filter and an internal filter, both of which are cycled, but the plants just take care of everything anyways. So excessive filtration just to keep the water clear of debris and add flow to the tank haha
Just crazy how impressive some plants can be with nutrients.
Highest nitrates I've gotten on this tank, even with ferts