Why did both of my molly fish suddenly just die?
I had a silver molly, a dalmatian molly, and a male betta fish in a 5 gallon tank together (please, dont say the betta fish harassed them and thats how they died, our betta fish has never once shown any aggression towards them, in fact, if anything sometmes it was the other way around). My boyfriend and I just cleaned their tank, and while we were changing the water we stuck them in a smaller fish bowl. They were in there for about 15 minutes, fine, and then all of the sudden the silver molly just started sinking to the bottom. She would try to swim to the top, then give up, and start floating on her side downwards. We quickly put her back into the regular tank, but she just slowly died. What was weird with her though was that while it seemed like she was dead, she randomly just DARTED across the tank out of nowhere, then floated to the bottom again, laid there for like 2 minutes then darted across the tank again. She did this a couple times before she finally died. We thought maybe there was just something wrong with her, seeing as we did nothing different in cleaning our tank, and we’ve had both fish for about 6 months now, no problems. Then suddenly the other one starting acting the same way, slowly falling on its back, floating downwards on its side. It seems like he’s struggling to stay at the top, so he doesn’t have to float to the bottom. He’s obviously going to die like my other one did.
We did nothing out of the ordinary. The water temperature was fine, we didn’t change all of the water. I don’t get it. It had to be SOMETHING seeing as both molly fish died. And the fact that our betta fish shows no sign of any problems. Something happened that just effected the mollies and not my betta.
Any ideas? I’m heartbroken.
check the temp, chlorine, ammonia, nitrite, nitrate, ph, and hardness. i am sure you will then have your answer
if you dont change their tank very often or changed more water than usuall it could be because they got used to the way the water was and when you changed it n made it cleaner they didnt have time to ajust to the change.
and i found this source that someone ealses molly did that when they were changing the water i didnt read it all just saw the same things u said n posted it here
1. 5gallons is MUCH too small for mollies (the minimum is 10gallons and some will argue a 20gallon is needed). 5 gallons is large enough for a single male betta and some shrimp.
2. you should NEVER change enough water to have to remove the fish, in a properly stocked aquarium you should only be changing 25% of the water once a week using a gravel siphon.
bettas are super hardy fish… they can live a few years in a cup (sad… they should NOT be kept like this but some people just don’t care) so the fact that the betta is fine means nothing. the mollies were probably suffering from poor water quality and the stress of being moved like that just killed them off while they were in a weakened state.
I’d suggest either getting a larger tank or not adding anymore fish with the betta as the tank is too small for more.
I agree with Kylie Anne in that you should NEVER change so much water that the fish need to be removed. The maximum that should be changed is 50% if water levels are particularly bad or you have just completed a cycle of medication. You are dramatically changing the water chemistry every time you change over this amount.
The ideal would be about 25% once weekly, using a gravel syphon and making sure to use a de-chlorinator on the untreated tap water.
Did you use water from the original tank in the smaller fish bowl? If not, it’s likely the mollies died from shock. If it was untreated tap water, even more so. Unfortunately, if this was the case, by the time you put them back into the main tank, the damage would have already been done.
Betta are hardy fish, which is why some shops still insist on selling them in small plastic cups (I’m very sad to say), which may be why they were able to survive.