I have a 5in red sev in a planted 75. Its working ok, but I don't see it lasting long term. I have tough plants in there - big swords & large anubias. All I've seen is tearing of the swords and digging up the anubias - nothing major. I feed 3x daily and shoot for a lot of vege. If for some reason I miss that middle feeding, I always have dug up anubias floating when I get home haha.