I guess I am going to have to call myself a beginner with the kind of tanks I'm trying to set up, so I posed this here :) I recently (reluctantly) sold my 75 gallon african cichlid tank because we moved to a mobile home and it just took up too much space. I'm glad that a friend bought it though, so I know my fish that I had for 8 years are ok :) With the cichlids, I'd consider myself experienced. I never lost one to sickness in 9 years and had a few 9 year old fish in there.
To sell the tank, I had to promise to set up a small one for my daughter, then I decided to do one for me too. Both are 15 gallons, one tall and one long. The tall one (in the bathroom) was already established for several years...it had just one big female angel, until a heater malfunction baked her overnight :( So I kept it going with no one in it for a while, transferring water from the 75gal once a week to keep it going with no fish. My daughter wanted another type of fish that has babies, so I got her some guppies for it.
The other new tank in the livingroom (15 long) is brand new. I cycled it for over a week, using water from the other tank, so it didn't take long (it really never did spike with anything, even when I added fish and its been going for about 3 weeks). I put platies in there, and then a betta.
Both tanks have sand substrate because I've always had terrible luck with gravel and my cichlids did great with sand. The bathroom one has a bio-wheel and the livingroom one has just a normal Aqueon filter and an air stone. Both have heaters and are about 75 degrees.
I am having problems with them though, and I'm at a loss as to what to do about it. The tap water here is VERY VERY hard. I have a test kit where you drop the chemical into a test tube of water until it turns color...when it turns color, that is the hardness. Well, I got up to 30 drops and it won't change color and I gave up. The chart only goes up to 12 :/ I mixed this water half and half with RO water, and the pH is still 8.2. Still cannot get a reading on the hardness because I don't want to use up the whole bottle of chemical LOL.
I was reading that livebearers should be better suited to hard water, but I have now murdered about 10 guppies in the bathroom tank and one platy in the livingroom one is now sick. They get body rot (some had mouth rot). Every single fish in the bathroom tank died. The only thing left alive in there is two snails.
I am not sure if I should just be switching the tanks to less hardness by making the RO water ratio higher, or is the problem something else? I keep reading that fish can acclimate, and especially livebearers to harder water, so is the hardness and pH maybe just not the problem? Should I put some medicine in there to get rid of the fungus? I used to have a friend who bred discus and he taught me to care for the water, not the fish, then you won't have to use medicine...so I've always looked to the water for the issue instead of just going to get medicine for them. Also could be that I just shouldn't have guppies? I don't know.