Hey everyone, I've been out of the country for 6 months and left my tank in the care of my mother. The water parameters are fine, but the fish and tank aren't looking too great. I have 3 blue tetras and a green corey cat. Yesterday night, the tetras were having trouble staying afloat and hovering towards the bottom, although they are usually very fast and swim in the middle. I fed them peas today and they're swimming around much better, but still not 100%. One of their bellies is pretty swollen, but the other two look fine. Also, the snail population is out of control. Any ideas/suggestions? I want to save these fish!! Thank you for all of your help.