The 29 gallon tank saga - getting it back on its feet
So. I've just started keeping fish. I did when I was in high school at my parents house and I've had small betta tanks for years but this year I finally got a larger tank - a 29 gallon tall by seaclear.
I set up the tank in December and being a rookie who didn't do all his research I added fish almost immediately - I also attempted a female betta sorority. I'm sure some of you know exactly where this is going.
The sorority actually did really well for just about 2 months - december and janurary. Then at the start of february I moved apartments and had to take down the majority of the tank - I was able to transport it with some water in the tank and about 5 gallons of the original tank water in a bucket. I set up the tank at the new place and at this time I also added new plant promoting substrate and some live plants. I added the girls back to the tank and everything was ok for a few days and then I started losing girls left and right. I found out at this point that my cycle was either never established or was lost as my ammonia was sitting around 0.25-0.5ppm. Nitrite also was high for a bit around 0.5, nitrate never went over 40. So I think I lost a lot of girls just due to imperfect water conditions which caused stress and disease in the already stressful environment of a sorority. I also made the mistake of continually adding new girls to replace the ones I'd lost - I was worried that with just a few girls the aggression could be directed at the weakest girl in the tank, resulting in her death. I realize now I was really just throwing fish at a problem and it wasn't going to solve anything.
After about a month of attempting to restock over and over and getting all kinds of disease and death - some extremely hard to diagnose - many girls seemed to have internal parasites, others had dropsy like symptoms, some had fin rot and still others died with no external symptoms whatsoever. Bottom line I lost all bettas and was left with my 8 white cloud minnows which I got over a month ago - these fish are amazing hardy and have never shown any symptoms of disease - I did have 3 of the original 11 die on me within the first week but they didn't have symptoms and with little fish like this I always assume some will be lost.
Anyway, about 2 weeks ago I lost/rehomed the remaining girls and decided to call it quits with the sorority idea. This is also when my water parameters finally reached the ideal 0, 0, 10 for ammonia, nitrite and nitrate (the tank is planted so a bit of nitrate is probably good?). I waited a week after the last betta was lost, did some serial water changes and monitored the tank parameters and decided that I could add new fish as the numbers were holding constant and the minnows were healthy. This time I decided to start setting up a community tank and I got two angelfish - I really wanted them to be the centerpiece of the new tank. I only added two fish and acclimatized them as well as possible following guidelines on this and other sites. They weren't perfectly healthy when I got them (typical of anything at petco) but they seems generally fine, one just had some ragged fins - especially the dorsal fin. I figured this would improve in the tank at home as the water was high quality and they would have no other aggressive fish in the tank with them.
This is not what happened. One of the angels spent a lot of time swimming up and down in the tank corning then bobbing along head up at the surface, while the other with the more ragged fins stayed generally hidden in plants, breathing very rapidly compared to the other fish. We kept monitoring them and three days after getting them the first angel (the more active and healthy looking one) starting swimming very strangely - on its side and even upside down - it did this for a couple hours before we found it dead on the filter. the other angelfish followed the next day - without the odd swimming behavior but it was still looking like it was breathing rapidly up until its death. other than behavioral things neither fish had external signs of illness.
So what could have killed them? Did I not wait long enough after the sorority fell apart? Could there be residual disease in the tank even after the serial water changes? Is there some toxin I'm not measuring with my API master test kit? I also add aquarium salt when doing water changes - but I only add as much to replace that which I'm removing, so I don't think the tank is excessively salty - but perhaps angelfish are very sensitive to even a little bit of salt? whatever killed them has had zero effect on the minnows who are still perfectly healthy.
I don't want to go out and get new fish just to have them die again - I'm tired of losing all the fish I put into the tank which is why I left the sorority idea behind but now I can't even get other fish to survive even in perfect water conditions (at least in terms of the cycle... the only other parameter i've measured is ph which actually tends to be a tad high 7.6-7.8)
So what do I do? how do I proceed? the tank is cycled and I'd like to restock it, but I don't want to add any fish to the tank I now lovingly call the death trap. Is there something I should be testing for that could be killing fish? does petco just have unhealthy fish? I'm open to any suggestions at all and I want to get this tank running right.
29 gallon tall
aqua clear 70 and tetra whisper EX30 filters
aqueon adjustable 150W heater set to 78 degrees
madagascar lace, red sword, anubis and java moss are all live in the tank