Plant leaves turning black/not bba
Hey all, anyone experience their plants turning black? Im almost positive its not algae as i cant kill it with peroxide. It happened in the past when i dont think i was adding enough fertilizer (ei based liquid) i trimmed and started to add more often amd my s repens seemed to grow alot better without the blackness. Fast forward to the current and ive switched to ei powders, adding the recommended amount and low amd behold leaves are turning black again.
Just wondering if anyome has experienced this before. Its not bba, im quite certain as its not fuzzy, and stsrts on the edges of the leaves.
Tank is a 4 foot 125, 4 t5ho and co2 injected. In the past ive tried lowering lighting durstion, and cranking co2, tried extra filter cleanings, vaccuming, and the only thing that seemed to fix it is adding more ferts.
Currently im following
1 1/2 tsp kno3
1/2 tsp kh2po4
1/2 tsp csm+b
3 times a week. And co2 is cranked pretty high