Sudden betta death
I had a beautiful pink betta die tonite. He was in a five gallon tank with a heater. No filter but kept water hyacinth from my pond in there. I just did a 100 percent water change two days ago,used water conditioner and floated his container to match water temp before putting him back in. I've been changing the water once a week. Have had him for several months. The only thing I did different was add small potted plants from my pond. They really love a lot of plants it seems. He wouldn't eat today so it happened pretty fast. Other betta is fine in other tank. Dead one had dark red inside gills and his pretty eyes were bulged out (sorry to be gross). I tested for ammonia and it was ok. Does anyone have any idea what could've happened? If my other one dies I won't replace them it's too stressful when you just want to give them a good home and they die on you.
Thank you, Sue