jen21

I would appreciate any advice as I'm having problems with my tropical tank, it's a 20uk litre with 3 adult mollys, 3 baby mollys and 1 platy. I perform a water change every 7-10 days.

The tank has been established for nearly 9 months and I've had no problems until now. The filter is being blocked up by sludge alomst daily, I have been cleaning it out in water removed from the tank which does not seem to help. Yesterday I took out all plants and gravel and thoroughly cleaned, did a water change and it seemed to clear up for a few hours.

Today the filter has clogged up again and the water is going cloudy. I've tested the water and all readings are normal. One of the baby mollys has been very inactive today and is swimming with his tail down so I'm quite concerned.

If anyone can offer advice I would be really grateful.

midnightwolf

i am sorry to say this but your tank is way over stockend and that is probially the reason for all this. 20 ltrs is only about 5 gallons and the only fish u could keep in a 5 gallon is a betta fish. as i see it you have 2 options:

1- get a larger tank, about 20 gallons would be nice but 15 might work.
2-sell or give away your fish and get a betta instead.

good luck, and i hope this helped.

gremlin

It sounds like you have more fish than your filter can handle. I have that problem with my 40 gallon - having to change the filter every day or two, but then I know I'm overstocked. You have 7 fish in a very small tank - a larger tank would definitely help. The problem will only get worse as the baby fish grow and produce more waste. Your filter was probably just barely keeping up with the four adult fish - then when the three babies grew larger, it just pushed your poor filter over the edge.

jen21

Thanks for the help, it's a shame as the shop where i bought the 3 adults said you could have up to 10 Mollys in that tank. I chose to only get 3 as i wasn't sure and then the babies arrived. I have a friend with a very large tank who has agreed to take the 3 adults as I don't have room for another tank. I really don't want to give them away but their welfare is my priority.

Since yesterday they seem to have lost their appetite, would this be the same reason?
Also, is there anything I can do for the little one that is looking unwell?

gremlin

Loss of appetite could very well be because of poor water quality caused by the overcrowding. Getting them in a larger tank with better water would be the best thing to do. Daily water changes and treatment with a water conditioner that can also de-toxify ammonia will help. Also, if you could get a second filter, that should help also. I would say keep no more than 3 of your fish - even that is really more than that tank can handle, but if you have the extra filtration, and keep a good eye on the water quality, they should be ok for a while. Really you need to consider getting those fish into a bigger tank. Your size tank might be ok for a betta or for a couple of african dwarf frogs.

jen21

I have cleaned out the filter again today, and done a small water change. The 3 adults will be going to their new home tomorrow, I'm sure my friend will take the others as well but not until they have grown as all the fish in his tank are fully grown adults.

They have now eaten as I put some mosquito larvae in which they love, however the small one that's not well was not interested. He's just staying near the bottom with his tail on the gravel, I'm very concerned but not sure there's much more I can do before tomorrow when I take the others out.

How much water would you recommend changing every day until the tank clears?

gremlin

40 - 50 % water change with a water conditioner (such as Prime) and test the water to make sure that the readings are all good. There is a section on the nitrogen cycle that can help with your readings. Ammonia should be 0. That is the single most important one with NitrItes a close second (which should also read 0). NitrAtes should be below 20. Your little one that is staying on the bottom could be suffering from ammonia poisoning. Improving the quality of the water may help, but you will need to test your water daily to make sure that it stays good.

jen21

I have been taking daily readings and today they were all fine, yesterday the nitrites peaked slightly over 0.3 so I did another water change but everything is back to normal today. The 3 adults were rehomed yesterday into a 180 litre tank so I'm sure they will do very well. The water is now completely clear and the filter is working well.

I am still very concerned about the little one though, it's still resting at the bottom and not interested in food. Every now and then if you make a noise it will shoot around the tank but then just lay on the bottom again. I am so worried, I expect to come down in the morning and discover he's not made it. Is there anything else I can do? Or if it was ill due to the poor water quality how long does recovery normally take?

Thanks again for the help so far