Nitrate dropped to zero
 

Anyone know what causes Nitrate to suddenly drop to zero, other than a complete water change? I was at about 10ppm just a week ago and now reading zero. Tested it twice thinking i screwed up the first time.

Tank has only been running for a month so far. Getting some green algae growth on the sand bed but not on the rock, perhaps that is what is sucking the nitrate out?

On the same note my Ammonnia is still reading 0.25 but at this point I think the test kit is not giving accurate results, i have never been able to get it to read lower than 0.25.

Some other paramters:
Salanity: 1.0025
pH: 8.2
Nitrite: 0
Nitrate: 0
Ammonia: 0.25 (or so it claims)
Alk: Normal
Capacity: 75g
Waterchange: 7g weekly

Whoops.

It's quite possible you really do still have ammonia. As far as the nitrate dropping, that means your live rock is working. You live rock works as a denitrator. My tank hasn't shown nitrates since a couple weeks after it was done cycling. :)

I thought it turned nitrite into nitrate, and water changes or other means get rid of the nitrate.

No. In freahwater, the only way to get rid of nitrates is waterchanges or a heavily planted tank (plants feed on nitrate).

In saltwater, you have the aerobic bacteria (on the rock surfaces, and sand surfaces, etc) that convert ammonia to nitrite, and nitrite to nitrate. The live rock hosts the anaerobic bacteria (in the middle of the rock, and under the sand) necessary to denitrate. The anaerobic bacteria convert nitrate to free nitrogen which is then released into the atmosphere.

Quite true this is why I keep a power head moving the water at the top of the tank it helps release the nitrogen and also helps bring in oxygen:idea:

What brand of test kit is it? If it's an elos, that jumps from 0 to 5 to 10, then I'd question how accurate it is at the 10 and under levels. If it's a salifert or the like then sounds like your liverock's doing it's job.