I have a 29g, 80 degrees, pH 7.6-7.8 (can't quite tell), nitrates - 0, nitrites - 0, ammonia - 0. Tank is only about 1 month old but I used filter media from an established 6-month-old tank that had been stable for months (also cycled with old tank material). Neither tank ever had any ammonia or nitrite spikes. grav
aquaclear 50 HOB
5 plants (mostly from my 10 gallon)
3 mollies (1 from my old 10 gallon, 2 in the tank for a month)
6 neon tetras (in the tank for about 3 weeks)
4 cardinal tetras (in the tank for about 2 weeks)
3 guppies (in the tank for about 1 week)
Everyone has been doing great in the roomier tank until this past week. I brought home 3 male guppies and after 3 days, one was looking unhappy. He would hang near the top, but not gulping, just seeming like he was trying to stay afloat. His spine also seemed less rigid (vertically) than usual - in other words, it seemed like his spine was a little curved head-to-tale. Then he would hang out behind the filter. I moved him to a 5-gallon quarantine tank with a tetra whisper 10 filter that I leave running in my 29 gallon for such emergencies. He died within the day.
Now it has been another couple of days and my black lyretail molly (who I've had for about a month) is starting to act odd. She seemed like she couldn't quite stay afloat, hanging out near the bottom, resting on the gravel (but upright), etc. As soon as I noticed, I set up the 5-gallon qt again, added a tablespoon of aquarium salt and moved her over.
Now I'm worried about her, but also for all of the fish in my tank! I shouldn't have bought the guppies because I noticed that one of the other tanks at the LFS
had a new batch of mollies with many looking unwell, but I was impatient to continue stocking my 29-gallon. Terrible mistake.
Is there anything I can do for my molly? I haven't noticed any spots, growths, fungus, worms, or anything like that - just the strange behavior.
Should I do anything preventative in my 29-gallon? I don't usually use aquarium salt because of my plants, but is it warranted in this case? I know it can benefit sick mollies but I don't know about the guppies or tetras.