Nasty White Slime - Help!

[Paddy]

Cleaned the tank yesterday and noticed the glass and filter all covered with slime. Now the fish are dying and all swimming at the top of the tank. I changed 60% of the water again but the slime is multiplying. What is this and how can i get rid of it before it gets rid of the kid's fish? Please help if you can. For info the tank is about 75L and has about 12 fish - mixture of tetras, guppys, mollys, sword tail etc..

Paddy

 

[black angel]

hi and welcome.
how long has the tank been running for? if its less than 6 weeks then it could be the new filter cycling and the mould is the start of bacteria build up. cant really say any more until you answer that question. knowing the ammonia, nitrite, nitrate, ph would help too.

 

[Paddy]

The tank's been running for about 18 months with no major problems. Nitrate 25mg/l, Nitrite <1m/l, pH 7.6.
It looks like a small amount of wall paper paste has been added to the tank (it hasn't by the way). The filter doesn't seem to be able to clear it and clearly the fish are short of oxygen as they are gasping at the top of the tank.

 

[WILDER]

You have a high nitrite reading there, sounds like old tank sydrome, have you cleaned the glass with a glass scraper or magnet, also i would do some water changes to fetch the nitrites down, when did you last maintain your filter.

 

[Paddy]

Old tank syndrome?... I this a technical term?
The filter is a jewel compact. The poly pads are changed weekly. The carbon filter went back in last week after a treatment for fungus, before that it had been in about 4 weeks. The coarse filters havn't been changed for a while although I have rinsed them through with water from the tank. How much of the water do you suggest i change and which of the filters?

 

[WILDER]

I would buy some new sponges and add them very gradually, like one old sponge cut it in half and replace half of the new sponge, then squeeze the old sponge you are throwing away onto the new sponge to get some good bacteria from it, don't touch the others for a few weeks do it very gradually, sounds like your sponges have had it, do a few daily water changes then test water again.

 

[Paddy]

Thanks I'll give that a try. How much of the water should I change when doing it daily?

 

[WILDER]

20% for now you have a high nitrite reading, good luck.