View Full Version : Elevated ammonia in a mature tank

03/09/2012, 11:06 AM
I stopped measuring ammonia a few months after my new tank cycle was complete (about 3 years ago). Last week I sent a water sample to AWS just for kicks and to see if I was missing anything. Surprisingly enough my ammonia was high (.16 mg/L).

I thought that after cycling only a major event (large dead fish rotting) would cause ammonia to rise.

Other than the fact that I haven't vacuumed my sand bed in about 4 months nothing major has happened in my tank.

Other than some water changes I'm not sure how to respond to the .16 mg/L ammonia

03/09/2012, 11:41 AM
Sounds like a testing error to me. Once a tank has gone threw its cycle the bacteria will use up all ammonia before it it detectable. Unless there is a large amount of waste breaking down (even then they bacteria will increase as ammonia increases) or a large die off of some kind. Re test with a few different kits to verify. If ammonia really is up then something like MB7 to increase bacteria population may be a good idea.

03/09/2012, 11:51 AM
Its funny you posted this because I was recently testing with my red sea ammonia kit (tests ammonium) and both of my tanks are showing about 0.12ppm toxic ammonia. Both systems are quite stable and one is supporting SPS. If you think about it there is a certain amount of ammonia always present, it isn't instantaneously pulled out of the water when released by your tanks inhabitants. There is always a minute amount present in the water column. Keep in mind a simpler test (API liquid) read 0ppm for me.

03/09/2012, 12:14 PM
Sounds like a testing error to me.

Yea, testing kit errors is why I sent a sample to AWT ... but I never even considered ammonia. You would hope that their methods would be more accurate than my $8 kits. Oh well. Here is their report.

Ammonia (NH3-4)
Natural Seawater Value: 0.010 mg/L
Acceptable Range: 0.000 to 0.050 mg/L
Tested: 0.160 mg/L
(HIGH) Your ammonia level is too high. We recommend the following possible solutions: perform a partial water change, clean any pre filters or sponges, remove any un-eaten food from the aquarium, and possibly the application of an ammonia scavenging resin. Persistent ammonia levels of 0.25 mg/L will cause regular fish mortality, with some species being sensitive to considerably lower levels.

03/09/2012, 12:18 PM
I think there is always ammonia around if you have fish. Many organisms use it and excrete it. I'd retest and wouldn't worry about it at .16ppm very much. I do not think a bacterial supplement such as Microbacter would be very helpful in an established tank.

Randy Holmes-Farley
03/09/2012, 12:20 PM
I wouldn't test ammonia on a stored sample. Breakdown of live bacteria and assorted organics in the water may release ammonia, and the rise of ammonia in natural seawater samples stored 24 h in a glass container is reported in the scientific literature. Same concern for pH: don't bother measuring on a stored sample.

There is also almost never a reason to measure ammonia in a mature reef tank with adequate live rock and/or sand. :)

03/09/2012, 01:05 PM
Thank you Randy, I am happy again.

I did a search on this forum for AWT .... sheesh .... I wish I had done that search $42 ago :(

Randy Holmes-Farley
03/09/2012, 02:51 PM

Happy Reefing. :)