Nitrate: how low is low enough ?


New member
How low SHOULD nitrates be ? I2go posted a thread expressing concern over nitrates at 17. Bertoni posted a reply which said that 17 is not an emergency but the levels should be brought down. Someone posted a link to an advanced topic where the author said he likes to see nitrates nearly unmeasurable on a standard home aquarium test kit. Contrary to that my "SW Aquariums for Dummies" book says anything under 20 is OK for a reef.

I ask all this because I am about to add my cleaning crew and would like to avoid killing them. My current water params using AP Saltwater Master Liquid Test Kit are as follows:
ammonia=0 (peaked at 0.25 and fell to 0)
nitrite=0 (also peaked at 0.25)
nitrate=15 (between the 10 and 20 colors on the test color chart)
temp= 79.5 to 81.5

The tank is a 75gal+20gal sump set up 2 weeks ago. Ammonia settled to 0 about a week ago. Nitrite about 2 days ago. The other params have been steady nearly from day 1. I used 30lb of Fiji LR and will probably add more as time goes on. I am considering making my own Aragocrete and adding Grunge....




New member
I like nitrate to be close to 0 just to avoid problem algae blooms. Nitrate level around 15 will not affect a clean up crew, at least as far as I know. When I started years ago I got lazy and went a few months without doing a water change. The nitrates got very high, in the 100s! It did not seem to affect my clean up crew, it just caused algae blooms that fed them. :)


New member
you can lower the nitrate by doing water changes. Also, the nitrogen cycle goes like this:
the break down of ammonia to nitrite and then nitrate is caused by bacteria. plants absorb nitrate, so if ur getting alot of nitrate, you can lower that amount by adding plants, but water changes are the best way to lower nitrates. sorry if u already knew that.


Premium Member
The cleaning crew isn't going to be affected by the nitrate level, not at any level close to the one you posted. Stony corals are more of an issue.

Water changes will lower the nitrate level, but if there's an underlying cause, the level will rise back very quickly.

Since the tank is still new, I would just wait and see what happens. If the nitrate doesn't drop on its own, there are lots of methods of controlling it. This article has a lot of ideas: