Urgent!

[doomedhazey]

I have a marble molly who i cant tell the sex. they wee fine earlier today and then i came home and they were laying at the bottom of the tank. I isolated them in a cup and theyre trying to eat but sink everytime they try to swim. What can I do? Im really concerned and dont want to lose them.

 

[Ch4rlie]

Can you provide some more information? 
 
Start with size of tank including dimensions.
 
How long has tank been running?
 
Has tank got filter and heating?
 
The more information you can give, the better. 

 

[doomedhazey]

5.5 gallon tank. its been running for almost two months. the tank has a filter and stays at a constant 80 degrees. My molly passed this morning but i would like to prevent my other fish from dying as well (I have 4 left). My molly was breathing very hard and would sink to the bottom of the tank constantly. They would try to eat and had no loss of appetite. I isolated them because one of the other mollies began to bully them.  

 

[DrRob]

Commonest cause of things like this is ammonia poisoning (or nitrite poisoning, by the same process). I'm not sure if you mean that the 5.5 gallon is the main tank or the tank you moved the sick fish into, but it's quite a small tank, particularly for mollies, which get quite big and have an appetite to match, producing a large amount of waste in the process, which then feeds the ammonia cycle.
 
We see these problems in tanks that are too small, so toxins build up between water changes, or in tanks that have immature or underperforming filters. It takes a while for the filter bacteria to colonise the filter properly, a process known as cycling. There are a few articles on the forum explaining the ways to best do it.
 
If the main tank is the 5.5 gallon then your problem is that it's essentially too small a space to keep mollies in, you're looking at 4 times that size as a minimum for them. Toxin build up will be essentially uncontrollable in that volume of water, and it'll happen again I'm afraid.

 

[doomedhazey]

Commonest cause of things like this is ammonia poisoning (or nitrite poisoning, by the same process). I'm not sure if you mean that the 5.5 gallon is the main tank or the tank you moved the sick fish into, but it's quite a small tank, particularly for mollies, which get quite big and have an appetite to match, producing a large amount of waste in the process, which then feeds the ammonia cycle.
 
We see these problems in tanks that are too small, so toxins build up between water changes, or in tanks that have immature or underperforming filters. It takes a while for the filter bacteria to colonise the filter properly, a process known as cycling. There are a few articles on the forum explaining the ways to best do it.
 
If the main tank is the 5.5 gallon then your problem is that it's essentially too small a space to keep mollies in, you're looking at 4 times that size as a minimum for them. Toxin build up will be essentially uncontrollable in that volume of water, and it'll happen again I'm afraid.

Thank you so much. I'll starting working to make a healthier environment for them. 

 

[Bubble.Guppy]

In my opinion, invest in a water testing kit for sure. They are somewhat expensive initially, but they last a long while. This way you can test the water and see where your water quality is. I would stay away from the cheap testing strips, as they can be inaccurate at times.
 
On a side note, Seachem Prime is a water conditioner to make tap water safe, and it also has binders in it that makes ammonia, nitrite, and nitrate non-toxic. You can use this for water changes and for emergency situations to lower your toxic levels that are deadly.