yup it's HC. I let it grow emersed for a few months before I filled the tank and had a pretty awesome carpet going, but I treated the tank with H2O2 and most of it died
It's done pretty well in low tech, though I wasn't too excited to pull it all up and replant it.
So far I wonder if a filter with higher flow would help with the cyano issue. Maybe a classic 2217. Maybe a spraybar... or some big lily pipes? I'm clumsy so I need to find someone who makes acrylic ones. I am struggling with light, too... LEDs are so deceiving, I don't know if I have too much light or not enough... that and I wish my regulator wasn't broken.
Cyano's a tough one, though. P deficiency seemed to be causing mine. When I started dosing it frequently it literally disappeared. My biggest tip would be don't get lazy... I had finally found a good balance in my tank but have lost it now due to lack of routine maintenance, trimming and replanting, filter cleaning, etc. The cyano's come back with a vengeance