dead lab's

Hi.
Put two new lab's into my malawi tank. They died overnight. Checked my water as all other fish were fine. It is a well established tank. I discovered a very high nitrate level of 140. Could this be waht killed them. I only do water changes once a month on the advice of my retailer. My tap water contains no nitrate so that is not the problem. I have done a 50% water change today and will do small one each day for a week to bring levels down. There is no other problem in the tank they were not attacked.

Hey

How big is the tank and how many fish in there?

Also 1 water change a month to me is way too long.
I think that could be the reason for the yellows dying.

I do a small water change say 10-20% once a week.

It's 600litre. It has about 30 fish.

Your nitrate level would be considerably higher than that of the LFS and your fish would have become used to the gradual increase in Nitrate. The new fish however had to get used to the change instantly unless you acclimated them over a period of a few days.

A few regular wc's is your answer to get the nitrates down to safer levels for adding new fish.

Yeah I thought so. I'm going to do a 10% daily for a week. Then check again.
Thanks

Quote:

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Originally Posted by paulyer

Hi.
I only do water changes once a month on the advice of my retailer..

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Your retailers a idiot .... do at least 40% once per week.

you can get by on once a month if you filter is removing nitrates. seachem matrix starts removing nitrates after 3-4 months.
However, if you dont want the odd fish dying every couple of weeks, the 40% Taksan recommended, will take care of that.
They should have a compulsory fish keeping course for retailers before they get into the business, so they can spot the difference between their face and their ass. A Certificate II in Ornamental Fish Trading sounds nice.

initially id be doing larger w/c

also utilise some bio zorb, several pouches would be the go