Help with Nitrite levels

Hi, I'm new to this board.
I've had my 55 gl tank for about a year now. I just brought in 5 discus. In the first week, most of my cardinals died and then 2 of the discus also died. I gave a course of Maracyn I & II. Now, my nitrite level won't go down. It's at 0.25. Ammonia is at 0.00; Nitrate is at 10.

Does anyone have any suggestions to bring the nitrite level down to zero? I'm thinking that nitrite went up because I used Maracyn which is a gram positive antibiotic.

For now, I've been doing 25% water changes every other day with Prime.

Thanks for reading.

First off welcome to the forum. I'm sorry to hear about your fish fatalities.
You might have had a Nitrite spike due to the amount of fish introduced at once.This may have caused your Bio Filter to do a mini cycle. I myself try not to use chemicals other then chlorine/chloramine remover at water changes. I would continue the water changes and see what happens.

Welcome to our forum.

It's very easy to over medicate, and some things will kill the beneficial bacteria that keep the ammonia and nitrite levels at zero. Like Shane said, partial water changes are best for getting rid of toxins. Discus are very sensitive to water conditions, and they need a warm temperature in a large aquarium. You should not add to the aquarium population until the nitrite problem is solved.

Thanks. I am not adding anything to the aquarium. But how long do you think it will take for nitrite to decrease to zero. I've been doing it for a week now and no changes so far.

Could take a few weeks for the beneficial bacteria johnarthur was talking about to grow back. Keep us posted.

Welcome to the forum. What terrible luck. You can also add hornwort to suck up nitrites since Discus are rather sensitive fish. Well any fish in particular are sensitive to nitrites.

If you have nitrite but no ammonia, the cycling process is nearing completion. It may, though, take a couple more weeks.

Yes, zero ammonia. So, I'll keep on doing water changes. Thanks!

WELCOME TO OUR FORUM...for your 55 gallon tank you change 40% water in every week.use dechlorination.
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this is my blogspot,go through this...i have discus for last 5 years...i only keep discus..if you have any problem with discus you consult with me or megham....