I just did a 50% water change just to see if it seems to slow things down and potentially bring the pH back to normal. The clerk said most people have had bad luck with RRFs except one customer. Now I’m starting to wonder if I’m gonna join the ranks of those who have killed them. Small tank, 4.2 gal/ ~16L
Late to the game, but I have some with same wood, and are doing fine. My PH is like 7.3 even with the tannins though. Mine were slow going, but once I removed the bulk of water lettuce, RRF prospered. Is the plant competing with anything? Is it an actual grow light? How is it dying? Is it staying on the surface or getting tossed around by current?
I needed fertilizers! I got some co2 + other stuff that frees up iron (flourish excel) and the RRFs exploded happily. They went from dying to sending out new leaves like crazy in about a week. Quite the turnaround. I think the water was just nutrient-poor for floating/non soil plants.