6 mollies in a 14 litre tank

[sudbates]

Can you post pictures of all the fish showing them from the side?


The OP is from Australia, not sure if they have TopFin here.
But a 30inch tank isn't that expensive and would be a much better choice.

 

[sudbates]

I

That's 28 times tank volume per hour which is way too much. That turnover would be OK for a 100 litre tank.

I thought of going with extra filtration, so that the water is clean for these 6 mollies to survive. Is extra capacity filter a bad thing? Will it harm the fishes?

 

[sudbates]

Yes, the tank is much too small for even one molly over time. This fish requires at least a 30-inch (75 cm) length tank, but preferably a 36 inch (90 cm) long tank. Males attain 3 inches/7.6 cm, females close to five inches/12 cm, some reaching six inches.

I was told by the petshop guys these mollies grow a max length of 4.5 cm.

 

[Essjay]

Never believe anything a shop worker tells you. Most of them haven't a clue. But even 4.5 cm fish need more swimming room than a 14 litre tank permits. Maybe a single fish which spends all its time hiding in the substrate waiting for prey to pass by might be OK, but not a fish that actively swims around.
What the fish need is room to swim. Mollies need at least 90 cm swimming length.

High filtration may suck up more debris but it won't remove more ammonia or nitrite than a lower powered filter. The bacteria which do this live everywhere in the tank and adding more media won't grow any more of them.

 

[Colin_T]

Balloon mollies don't need as much room to swim but there is a platy and swordtail in the tank and they need a bit more space.

Because balloon mollies are squished up (their bodies have been shortened), they have more trouble swimming and won't tolerate too much water movement, so a bigger filter is probably not good for them.

You need a picture on the back of the tank to help the fish feel more secure. You can buy aquarium backings or use coloured card, a plastic bin liner, or even newspaper. Just tape it to the outside on the back of the tank.

 

[Byron]

I concur with what @Essjay and @Colin_T posted, and would add that mollies also have a higher impact on the water quality because they are primarily (but not exclusively) herbivorous. Fish like all animals that eat more veggie foods need more to get the nutrition, and that means more waste. Filters can handle some aspects of the waste, but not all. Massive frequent water changes will help, but having larger tanks means the water quality will not deteriorate as rapidly and this is better for the fish in the long run.

Colin mentioned balloon mollies...please, do not buy "balloon" fish of any species. The process used to "create" these fish is cruel and inhumane, and it does permanently harm the poor fish. Only by not buying them can we hope to have the practice stopped.