Well established cold water native tank with plants dying all of a sudden
I have a 55 gallon cold water native tank with some perch and bluegill (tank with lots of pygmy). I started out with warm fresh water, bought CO2 tank and fertilizer and substrate and tried to grow plants and just couldn't do it. So i gave up and switched the tank over to cold water native and left it alone. No CO2, low light and small filter. The plants started to grow like crazy. Mostly just pygmy chain sword and some crypts and or anubias? For almost a year it's been a great tank with no maintenance. Just weekly to monthly water changes. I've been able to pinch off the trailers and plant them in my 125 native tank (pic below with driftwood and minnows). And they've also been doing well. The grass was growing like crazy but the two broad leafed plants weren't doing well, then I started adding a fertalizer tab once a month and they did better.
But all of a sudden Pygmy chain started dying off fast. Not sure why? Do you suppose the nutrients in gravel just go too low? The tank was doing well for almost a year and a half. I also put some of the grass in my 75 warm freshwater, with low light, and no CO2 but they aren't doing well there either. Weekly water changes, cories and rainbows, some algae problems in this tank. Can't seem to beat that either.