My Fish Keep Dying..please Help

[krissy22]

Hello All
We recently got a  2 foot aquarium, we have the heater in it set to 24-26C. We have a filter called Crystal Clear Aquarium Filter 380. We were given some cichlid african convicts, which have been doing quite well.
My husband went and bought some mollies, black tetras, bristlenose catfish and a couple of others, plus 2 snails and there is a baby yabby in the tank as well.. We had a couple of fish die a day or so after putting them in the tank, and have been averaging one a day ever since. We did a complete water change about 3 days ago as my son put milk in the water, but even with the water change they have been dying off steadily.
We decided to completely clean the tank as we figured something may have been wrong and put them into a smaller tank as we only had a handfull of fish left, overnight we lost 1 x mollie, 1 x bristlenose, 1 x tetra and 3 x convicts.
Can anyone help me as its getting quite expensive replacing these fish.
 

 

[crash274]

Are you sure milk is the only thing thats been spilled in the tank?
 
Sounds like not enough circulation from what you've said, but thats a rough guess. Quick fix would be adding an air pump and airstones to get water moving out of dead spots. You'll want to look at your intake/outtake locations and flow and possibly move or modify them. Do you have a test kit? Thats the only way to tell whats going on level wise.

 

[Ninjouzata]

Did you cycle the tank? If you don't know what cycling is, look at the article that is at the top of the page 'Cycling a Tank.'
As has been said, if you havn't already got a test kit, you really need to get one so you can check your water parameters. Try to get a liquid test kit as strips are very inaccurate.
If you do have a test kit, what are the readings?

 

[DoubleDutch]

Don't know convicts very well, but a 2 foot communitytank seems not the right environment for these guys. Or am I wrong?

 

[Zante]

Don't know convicts very well, but a 2 foot communitytank seems not the right environment for these guys. Or am I wrong?

 
You're not wrong there. As well as one pair of convicts overstocking the tank by themselves, once they spawn they will kill everything that moves.