Why are my fish dying?

[Reese and Chase]

I had 3 molly fish, tonight it went down to 2. I noticed my molly fish seemed unhappy and the water was cold. So I bought a heater. The heater keeps the tank at 78°F, and tonight I went upstairs to see my molly fish looking as if he was gasping for air with his gills. The filter is on one of the highest settings the fish can live in, so I did some research and thought it could be overheating because the symptoms described what he was doing. Later tonight he passed, so I thought maybe the heat was off and too hot or cold. I put a thermometer in the tank and it said 78°F which is what it is supposed to be at. My other mollies seem to be doing good and showing no signs of overheating or sickness. Anybody know what happened? I am trying to figure it out so I can make sure my other mollies and continue being healthy.

[Reese and Chase]

I’m sad to say 2 of my molly fish have passed tonight and my 3rd and last molly is heading in that direction. I have 2 African dwarf frogs and one Mystery snail and they seem happy and healthy. We switched them into a different tank and my molly that is still alive seems perfectly fine but now he is showing the same symptoms as the other fish. He is laying on his side and his gills move rapidly before he gets up, swims for a second before repeating the process. I don’t think I can save him because I’m not sure what is wrong. We had a heater and it broke a few days ago, the glass cracked and we just found some metal pieces in the bottom of the back filter area (where the fish can’t get) and maybe that could have something to do with it. Anybody know if the heater could have caused it or a infection?

[Reese and Chase]

2 of my molly fish have died tonight and one seems as if he is about to. I think its swim bladder but I want to know for sure. The fish is swimming to the top of the tank and then sinking to the bottom. He also suddenly starts swimming again for a second before laying at the bottom again. He has been doing this for around 15-20 minutes and he is still fighting. Is this swim bladder?

[Aiken Drum]

There is a lot going on here across 3 different threads, but they are all related so ive merged them all into one thread to try and bring all together.

First off, can you give some more detail. As much as you are able from the "unhealthy fish" sticky.

https://www.aquariumadvice.com/forum...his-32451.html

If there is something you dont know, say i dont know rather than just missing it.

Just a quick one on the heater breaking. Do you have any idea how that happened? Might you have left it on while you did a water change?

[Reese and Chase]

The heater broke because it was glass. I took it out from the tank and the temperature change made the glass crack if thats helpful.

[Aiken Drum]

Originally Posted by Reese and Chase

The heater broke because it was glass. I took it out from the tank and the temperature change made the glass crack if thats helpful.

Good to know how you broke your heater. Please answer the questions in the sticky, because without that there is basically nothing to guide us as to what caused your fish deaths.