Loaches Online Forum

following my most recent water tests i was surprised to find the nitrate levels in my tank have risen from 0ppm to 10ppm. i wasn't sure what to do but i carried on and did a small water change as normal. after waiting a day i tested the water again finding that nitrates had risen further to 40ppm!
how do i get nitrates down to 0ppm again? and why did they rise in the first place?? this is the first time this has happened and i'm getting a bit confused...

Just off the top of my head... rising nitrate could be due accumulation of detritus somewhere in your tank. Check your filters for abnormal fouling/accumulation. When was the last time you moved your ornaments and cleaned behind and underneath them? What kind of substrate do you have and when was the last time it was vacuumed? Has anything changed in your tank recently?

during the water change i vaccumed up alot of broken plant leaves. (i have fine gravel by the way) i'm sure i got the vast majority of the bits and some uneaten food. nothing has changed as far as i can tell... all my other tests like nitrites and ammonia are 0...

This is normal

Nitrifying bacteria will remove ammonia just about as fast as it is formed. So ammonia shows 0 ppm all the time. They turn it into nitrite. Live plants use ammonia as a source of nitrogen, too.

More bacteria turn the nitrite into nitrate. Live plants will also use nitrite after the ammonia is gone.

Nitrate builds up in the tank. The bacteria that might remove it do other things that we do not want in the tank, so we do not encourage them. Live plants will use nitrate when the ammonia is gone.

In a high tech planted tank live plants and a small fish load the plants can use so much nitrogen (in all three forms) that you might need to add nitrogen so the plants are not deficient.
In most tanks there are more fish and they are fed more food than the plants can use so the nitrate builds up.

Water changes are the best way to remove it.

As for why the test results jumped the way they did, I have no idea. The timing on the tests is pretty critical. When the test showed only 10 ppm perhaps you had read it too soon; then the 40 ppm reading was done when you read it a few seconds later???
Other things can contribute to odd readings.

Water change, vacuum up the debris that is on the surface of the substrate.

hmmmm...thinking back, i have been feeding the fish a little bit more than usual and i have 2 less plants than i used to since my biggest goldfish decided that they looked yummy...could it be the reduction in plant life in the tank recently upsetting the balance then? perhaps i need to replace my filters pads or just give them a good rinsing

Reduced plants in combination with increased feeding could very well be the cause. Rinsing your filter pads in tank water would be a good precaution.

The filter media is where the bacteria are living. Do not throw them away. Rinse in water removed from the tank for a water change so that you do not kill the bacteria and reuse the filter media until it is falling apart.

i'll try rinsing the filter out in tank water and doing another gravel vac. i'm going to get replacement plants for the ones that were distroyed.
thanks for all the help!

*sigh* well i've tried all manner of techniques to try and lower the nitrates in the tank and its still not working. they haven't dropped really at all i just can't figure it out!

Do more frequent and bigger water changes.

Feed less, especially feed less of the high protein foods. Feed a little fruit and more vegies.

Add more plants. (Difficult with Golds- Some will destroy plants just to have something to do, but try Java Fern, Anubias, Hornwort as reasonably tough plants that Golds usually leave alone)
Have a separate tank that is really well planted, and pump the water from one to the other so the plants are safe from the fish.

Bigger tank will dilute the nitrates better between water changes, but you will still need to keep up the water changes.

Fewer fish (and therefor less food)

Against polution,...dilution.
Good water changes is the best way to keep balance...