I don't even know where to begin! I am having several problems!
Obviously new to this...
Testing PH 7.5, Ammonia - 0, Nitrite - 3.0 ppm, Nitrate 40 ppm, KH 180 ppm, GH 180 ppm with API test, dip stick. Tank has been running about 4 weeks and is 29 gallons, about 30" long, 12" wide, 24" deep. I changed 10% of water after 2 weeks. Tank is mostly city water, treated with API stress coat and stress zyme. But I did the water change using distilled water because I am trying to lower the GH and KH. Also adding API Leaf Zone for fertilizing the plants once a week. Fluval 305 canister with carbon, bio max, and foam. Feed hikari micro pellets (large pinch) twice a day and a cube of brine ship in the middle of the day. CO2 Natural Plant system injecting CO2. I added an airstone in one corner, because I had a surface film and the angelfish were gasping at the surface... the airstone has solved the surface film problem and the gasping issue, but I think I am depleting the CO2? Also: T5HO lights, two 24", one 5400K, one roseatte.
I have two angelfish and four red minor tetras, all about an inch- inch and a half long. The tetras are sometimes swimming eradically (in the morning) and chasing each other, and the tops of two of them have turned black. One of the tetras is pale. Angelfish seem fine. Angelfish were just added a week ago and it seems that the behavior of the tetras has been influenced by this addition, although the angelfish aren't even slightly aggressive.
So I suppose my questions include (but are not limited to):
1.) I did the 1st water change with DI water and will do the 2nd, 20%, with RO water. I think I need to add elements to this, but I'm not sure what type. I have Equilibrium but don't want to use it because it raises GH and i am trying to lower it.
2.) Should I only be running the airstone at night? Or not at all?
3.) I am having an algae problem, and understand that if I can fix the water chemistry, my algae problem with diminish, but not sure how to go about fixing the water.
4.) Is the black on the tetras a bad thing? Is that normal?
I think that just about covers it. Much appreciation to anyone who can help. All the research I've been doing just leaves me asking more questions...