View Full Version : Nitrates always zero...

06/28/2017, 08:00 PM
Now I'm not complaining, just super curious...I can go 3 months (well, probably longer, I just always cave after 3 months or so) without a water change and my nitrates never reach a detectable level (API test kit - second one, as I figured my first was ineffective).

How is that possible? Is it just that my bio-load is so low? I have 4 fish, crabs, conch, cleaner shrimp, a handful of corals and an anemone...my tank is 24 gallons and is 4.5 years old.

Is some level that I'm not measuring reaching an unsafe level? My tank is 24 gallons, and I have a tunze 9002 protein skimmer and a phosban reactor.
Thanks for reading :beer:

06/29/2017, 04:26 AM
A low bioload will definitely help achieve an undetectable nitrate level but that does not mean you don't have nitrate in the water. Hobby test kits will not detect nitrate when it drops roughly below 0.1 ppm even though the color chart accompanying the kit shows a color level or absence of a color corresponding to zero ppm.

06/29/2017, 09:49 AM
Gotcha. But how are they getting down so low? Could the xmas tree coral be sucking it up?

06/29/2017, 11:33 AM
Some ideas

Phosban is removing phosphate
Aragonite is removing phosphate
Coral, coralline, phytoplankton and bacteria are doing their share to assimilate phosphate and nitrate

06/30/2017, 04:11 PM
Thanks Dan. I guess I could have worse problems on my hands.:spin2:

06/30/2017, 04:54 PM
If you truly have -0- nutrients (or very close) you will be able to go 10 days without cleaning the glass

06/30/2017, 04:58 PM
10 days with no visible algae/film on the glass? I clean the glass roughly every two weeks, but it's definitely not spotless at 10 days

07/01/2017, 04:12 AM
There's no particular reason to assume that your tank will accumulate nitrate over time. None of mine did, after I removed a crushed coral substrate. Live rock and skimmers can remove a lot of nutrients, for example.

07/03/2017, 10:39 AM
Nitrate(NO3) is generated primarily by ammonia oxidation; by ammonia oxidizing bacteria(NH3/NH4 ---> NO2 --->NO3) the first part of the nitrogen cycle cycle. Most
of the ammonia comes from decaying matter and fish expeeling excess nitrogen ; some ammonia is taken up by bacteria and other organisms directly ; some of it is oxidized to nitrite and nitrate. So, if there is little decaying matter or heavy ammonia uptake by organisms there will be less to oxidize to nitrate. Also, anaerobic denitrification whereby nitrate is converted to N2 ,free nitrogen gas also depletes it.
It can be difficult to get a balance between nitrogen inputs via foods et alia and use via uptake by organisms and/or anaerobic dentirfication . Often an imbalance tilted toward inputs leads to a buildup in nitrate . Sometimes but much less often, nitrogen deficiencies occur.

Your animals look healthy, so I wouldn't worry about a nitrogen deficiency. Though it might be possible to avoid the need for a phosphate remover with a bit more nitrogen;say barely detectable on a Salifert test kit but less than 1ppm.