Mollies Acting Funny?

my female creamsicle molly and my male dalmation molly are very active, I don't think ive really ever seen them stop moving for the 5 or so days ive had them. ever since I got home from work theyve been huddled together behind the heater. I felt this was very weird behavior so I did a 30% water change (I had done one yesterday as well but my tank is not fully cycled yet). they came out and swam for a little and now theyre right back to being huddled together behind the heater. I don't have many plants in my tank yet so I guess it would be the only real “hiding spot”.. its just very strange because they never stop moving. any idea?


  • DD1E0BEF-6C98-44DF-B200-F948A1BD7FC3.jpeg
    60.3 KB · Views: 53
now all the fish in the tank are in the corner of the tank just hovering?! what's going on?? I'm so confused!


  • BEF59647-B606-4B43-99C9-23401FBE0057.jpeg
    69.3 KB · Views: 78
  • AAF66B29-C8A6-4D94-9411-CBAF3BC1BE2E.jpeg
    61.8 KB · Views: 65
its 10 at night and I don't have a test kit. are these symptoms of something?

put some food in the water and now shes back to darting around chasing the others being the big bully she is. I think theyre fine. maybe they were resting? weird.
Last edited by a moderator:
its 10 at night and I don't have a test kit. are these symptoms of something?
Did you use any dechlorinator or or prime when you did the water change? Do you have Prime or something similar? Do you have good water movement? Could be an oxygen thing, could be chlorine or ammonia or nitrite. Prime will help that. Check the temp also. Might be the reason they're huddling by the heater
yes I have API water conditioner, it says 3ml per 15 gallons. I don't have anything to measure less then a ml so I just put a couple drops in the 3 gallons I did during water change, hopefully that works? the temp is 77, I have it set to 82 so the heater is on. would they be able to feel the heat coming off of it? and I have a filter that produces a decent amount of small bubbles on the surface, would they stay towards the bubbles if it was an oxygen thing?

I put some food in the water and everyone came out to eat, my creamsicle turned into her normal self chasing around the boys being the big bully she is. but maybe 15 minutes later theyre back huddled behind the heater..
Last edited by a moderator:
The bubbles don't add O2. That comes from the surface movement. Yes they can feel the heat. Does API say it deoxifies ammonia and nitrate?
it says it removes chlorine, heavy metals, and chloramines. I thought the purpose of the water changes was to help the amount of ammonia? I have an air pump but I'm using it in my african dwarf frog tank as a sponge filter. if I need to I can move the frogs and pump to the 10 gallon, frogs won't be happy tho.
what would cause a nitrite spike?

I moved the heater to see how theyd react, and they followed it. my male betta keeps flaring and kicking the male dalmation out. maybe its just a nice spot because its warm?
Last edited by a moderator:
I don't have anything to measure less then a ml so I just put a couple drops in the 3 gallons I did during water change,

Go to your nearest pharmacy (Walmart, shoppers, rexall, whatever) and ask them for some medicine syringes. They should be free and they should offer you a couple of them.

I have several on hand at all times. They're great for dosing water conditioners, fertilizers, anything that you need in small amounts.

Just be careful not to put the tube into the bottle as it can take the ink off. I pour the liquid into the cap of its bottle and take it up from the cap. Then you can just dump whatever is leftover in the cap back into the bottle.
82 degrees is rather warm for the mollies. I'd keep them about 74. That's interesting about them following the heater. I'm assuming it's because they want to hide. I've never kept a Betta with other fish--too many stories here about them going rogue even after months of living with tank mates. I prefer to avoid blood baths :0
the first male crowntail betta I had was very shy and backed away if any fish came near him. the male veiltail betta I have now flares his gills now and again at my male molly but my female molly runs the tank and hes scared of her. thatd be horrible if something happened.. ill turn the heater down some. they all seem fine now, moving around more.
Your tank being unfinished with the cycling process may very well be the problem. I would suggest getting a test kit as soon as possible and seeing what might be the problem. It's likely ammonia or nitrites though. If you see the fish sort of gasping or breathing really fast or getting discolored, I would say it's one of the two toxins I mentioned above. I hope they get better!

Latest threads

Top Bottom