I have had a young adult male axolotl (Smaug) for about a year now. Recently when testing water parameters I have found that the nitrate levels are very high (80ppm), but both nitrite and ammonia levels are at 0. I currently do a 20% water change once a week. Should I perhaps increase this to every 3 days until I can get the nitrate levels down?

  • Tip: collect the cold water from the shower which is running until warm water arrives. Depending on the local installation it can be a lot. Commented Jul 23, 2017 at 19:31

2 Answers 2


Water changes will indeed reduce nitrate levels within your tank and with 80ppm you'll definitely want to reduce that as soon as you can.

You could increase the percentage of your water changes, but one thing that I've found has helped a lot is growing a plant such as pothos (formally referred to as Pothos aureus, also commonly known as devil's ivy) in the top of the tank with the roots trailing into the tank. It grows extremely quickly and has helped keep my nitrate levels much more manageable. Planted tanks in general help to keep the levels down, but if that's not possible, I'd definitely recommend giving pothos a try. This technique is commonly called 'aquaponics'.

This is a fantastic video explaining the process: https://www.youtube.com/watch?v=RcDoh0NcXLU

P.S. What a great name for an axolotl!


Test your tap water for nitrates to be sure that isn't contributing to your problem. And yes, more frequent water changes can help with keeping nitrate levels down. The addition of ghost shrimp can also help, but they may not last long as axolotls tend to find them very tasty.

I have a similar issue in my tank (high nitrates, close to 0 ammonia/nitrites). To solve this, I performed a 70-80% water change. After a few days I did a 30% change. Then monitored it and now do ~25% change after levels start creeping close to 40ppm.

  • How can adding ghost shrimp help decrease nitrates? I've not heard of that before. I would have thought they would fractionally add to the nitrate level.
    – Henders
    Commented Aug 12, 2017 at 20:42
  • @Henders Ghost Shrimp are scavengers and do an excellent job of cleaning the aquarium of rotting debris and algae. They are effective at actively reducing nitrates within the aquarium and having a very low biomass footprint. (For more info, check out aquariuminfo.org/ghostshrimp.html) Commented Aug 13, 2017 at 0:14

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