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nitrate and nitrite spike!

434 Views 2 Replies 3 Participants Last post by  fishscale
Hi all,

i rinsed the filter from my 50g yesterday, (took out my ceramic material, rinsed the sponges in the water from the canister filter) and added a bag of purigen to remove the yellow-ish tint from my water.

today - added 20 tetras and a few hours later when i checked my water, my nitrate was at 250mg/l and nitrate was at least 10mg/l! this was really weird because before i added the fish my JBL paper dips were still showing about 10 mg/l of nitrate and 0 nitrite.

i've never experienced spikes in no3 or no2 like that before. i've done the same thing on my smaller 15g planted a couple of times (paper dip showed more nitrates but a few hours and everything was back to normal), even though it has double the amount of fish and half the number of plants.

so far i've only lost all my yamato shrimps. other inhabitants such as plecos, synodontris, tetras, cichilds, still swimming about happily, plants are growing very quickly, pearling every day (i read its caused by injuries, but i'm not sure if all the new leaves could grow damaged either).

does anyone know what might have caused this? and is there a way to make my aquarium more stable too?

please advice!
1 - 3 of 3 Posts
Switched the purigen and the KNO3 sounds like............

250ppm of NO3 is a lot........ assuming that's a correct reading.
Rinsing should remove most of the OM and clean things up, you might have a touch of NO3/NO2/NH4, but if you do a 50% water change after, add dechloro etc, there should never be an issue.

Paper strips are not the bets method to measure or test for any thing really.
Use a good test kit and calibrate it.

Tom Barr
A couple of things:

Your paper dip strip tests are not very accurate. It is better to get some tests that use droppers.

20 tetras is a large fishload in a 50g, and could have created enough ammonia to throw off your water parameters. Your bacteria colony was probably not equipped to handle it.

I don't know if you rinsed your media too much, but if you scrubbed it, you might have taken off a lot of the bacteria.
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