Hey guys! I'm wondering if someone can help me identify a problem in my tank. I have a 20g long that I planted back in April/May, and the stem plants in it have been struggling since the beginning. Their leaves are thin, have small black holes, and tend to melt again and again. I trim them, replant, and they do a little better for a while. Then repeat. (I haven't added any new plants. So they're still alive...just not flourishing.) I set it up with everything I could find that online said to have to have a thriving planeted tank, barring Co2 (I am using Easy Carbon instead). Specs are as follows:
Light: Beamswork DA 6500K 0.50W Series LED, set at max with a timer so it's always on for 11 hours a day
Fertilizer: Easy Green from Aquarium Co-op (twice a week)
Carbon: Easy Carbon, dosed at the proper amount, once every day (in the morning).
Substrate: UNS Controsoil (black)
Plants: I'm honestly unsure. I stuck a whole time of kinds in when I started the tank and just watched to see which would stay alive. Only a few kinds survived the initial melt back. One is a Rotala of some kind (it has bright pink on the undersides of its leaves?)
Any advice or thoughts would be welcome. I've been trying everything I can think of for months to help them thrive better. Adjusting the light, the amount it's on for a day, doing more water changes, less water changes, etc. Nothing seems to be working. My next thought is maybe they need more nutrients from the substrate than it is giving them? So maybe adding root tabs would make a difference? It really seems like they're missing something vital but I don't know what, and I don't have the resources to test trace elements. Any and all help is appreciated!