Hey nice looking freshwater tank, I have to ask a few questions
1. I thought most "freshwater" rays were acctually brackishwater, is that the case with yours or is that a ray that i didnt know about?
2. I also heard that knife fish are really an aggressive fish, they sleep all day then come out at night to eat the other fish while they sleep.
You should really get some more plants, My tank is so full of them I have to trim them out once a week. But algae growth is almost nill. My secret is injecting CO2, I took a big soda bottle and put a rubber cork/stopper on it then put an air hose through the rubber cork, then added sugar, yeast, and water into the bottle, instant CO2, plus you get a REALLY good alcoholic beverage (im seriouse
). After I did that my plants started taking off like crazy, oh and I add iron weekly. Everything loves it and is growing great, well almost everything. My stupid fish will eat any new plants I put in so I am now stuck with the plants I have in the tank. I think if I added more lighting it would probably help, but I really dont care that much. One of the funny things is I have this sword and if you know swords they grow these really big leaves, but my fish always eat the leaf down to nothing so only branches grow no leaves, really funny. I enjoy my freshwater almost as much as I enjoy my saltwater. I also have substrate tips if you want them. Had to learn the hard way, but I have now learned. If you want some of my hardier plants, I could try to get you some for some sort of trade.