Nitrates Rising With Water Changes

[Corndog]

Hello everyone,
I started a 55 gallon tank around 10 weeks ago. I currently have 12 guppies, 2 kuhlis, 2 mollies, and 1 rainbow shark with a large bubbler. I have been having difficulty getting the nitrites down, they have been testing off the charts. I was having some trouble with ammonia and nitrates, but recently they have been testing at 0 ppm. Yesterday, I performed a 40% water change with the gravel vacuum in hopes of reducing the nitrates. However, when I tested the water today, the nitrates read at around 40-80 ppm and the nitrites were still off the charts (a very bright purple with the API freshwater kit). I'm worried that the water I am using has nitrites and nitrates in it naturally, but I need to test it to confirm that theory. Does anyone have any suggestions if that is the case or in general? Thanks!

 

[Aiken Drum]

There are lots of reasons why your water might be seeing high nitrate.

Firstly, it could be in your tapwater. Nitrate is common in tap water at varying levels. Here in the UK 50ppm is allowed, other places have varying allowed levels and its entitely possible for nitrate to exceed allowed levels. According to our water company we have 7.8ppm nitrate from our tap. Try testing your tapwater, or get a report on your water quality from your water company.

Your cycle is probably establishing now, so any ammonia is going to nitrite, and some of your nitrite is going to nitrate. It doesnt take a lot of ammonia to produce a lot of nitrite and nitrate. If ammonia and nitrite has built up and your cycle suddenly kicks in, then the end result could be a lot of nitrite and nitrate.

Some ammonia could also be in your tap water and not from fishwaste. Or rather treated with chloramine, which breaks down to ammonia and chlorine when you add water conditioner. Ammonia, regardless of source will process out to nitrite and nitrate. Again test your water or find out what water treatment your water company uses. You could be overfeeding. Waste food will also be putting ammonia into your water.

Water testing isnt all that accurate. All kinds of things can throw out a test. Those historic 0ppm nitrate tests? Maybe you had nitrate but for some reason the test didnt pick it up. Maybe you didnt do the test correctly and now you are. Or maybe something else. Its a home test kit not laboratory testing. Take your test results for what they are, a guide to whats going on. They arent an accurate assay of water parameters.

Of more concern to me is the high nitrite. Fish can live with high nitrate, but nitrite off the testing chart will be causing long term health issues with your fish. Do 2 x 50% water changes a few hours apart today and another 2 tomorrow. You need that nitrite down to no higher than 0.5ppm so keep up with water changes daily until nitrite is at safe levels. If back to back, big water changes doesnt bring it down then let us know.

I would also cut down on how much you are feeding, at least until your water conditions are safer. Either as much as is eaten in 1 minute daily, or as much as is eaten in 3 minutes every other day. In normal circumstances as much as is eaten in 3 minutes daily.