Large water changes input

[kien]

if done carefully (similar parameters as Aquattro suggested) a larger water change (50-80%) should go just fine. This is how I have done tank transfers in the past. Fill new tank 20% with old tank water then the rest with new water. As others have said, you don't want to be doing this on a frequent basis, but for a one or two off event for quick and short term correction purposes larger water changes are fine. A few weeks ago I did two consecutive 50% water changes in my tank to help flush out a treatment that I did on my tank.

[waynemah]

Originally Posted by sirruckus

actually I haven't cleaned the canister filter - all sponge material etc. has been removed, only the ceramic balls are inside.

The Ceramic balls might be the cause of your nitrates... If you have room in your sump, you might want to consider sourcing a zeovit reactor, use the zeo media and go on the base system (Start, Bak, Food). It's a fairly proven system and well supported.

[Duker]

Originally Posted by waynemah

Since it's to the point where there are casualties, it might be a good idea to try and reduce the nitrates fairly quick.

I would perform a 20% water change every 2 days until the nitrates are in check.

Yup, I agree do two consecutive 20% water changes a week for the next month or until nitrates are in check, reduce the amount of food if it's crazy amounts, and I would also suggest getting yourself a phosban reactor and use some bio-pellets. I had very high nitrates then I put a bio pellet reactor on with the CORRECT sized pump for bio pellets and they went from 50-5ppm over 2 months. I now never have nitrates over 2ppm. Good luck.

[sirruckus]

Originally Posted by Duker

Yup, I agree do two consecutive 20% water changes a week for the next month or until nitrates are in check, reduce the amount of food if it's crazy amounts, and I would also suggest getting yourself a phosban reactor and use some bio-pellets. I had very high nitrates then I put a bio pellet reactor on with the CORRECT sized pump for bio pellets and they went from 50-5ppm over 2 months. I now never have nitrates over 2ppm. Good luck.

that's reassuring to hear - just picking up my bio pellet reactor from the post office today actually.