Where did the Nitrates go? - Aquarium Advice

Skyrmir · 06-12-2005, 01:40 AM

My tank just finished cycling yesterday and being the impatient bugger that I am I went out and picked up 4 Zebra Danios and 6 Harlequin Rasboras. Up till now I've just had 2 danio's and a pleco in there.

Figuring I just dumped a decent load of fish in a 20 gallon, I expected to see some ammonia starting up. It's only been a day so I figured at worst it'd just be detectable so far.

Right now my tank is testing at 7.2ph, 0 Ammonia, 0 Nitrites, 0 NITRATES. Seeing as I didn't get a test kit until a week after getting fish, I've NEVER had a 0 reading of nitrates. I've done water changes to keep the nitrites down during the cycle, and the nitrates stayed 10 or below the whole time until now...now they're 0. There are only rocks ornaments and fish in the tank. So what ate the nitrates? I've tested it twice now with the same results.

FawnN · 06-12-2005, 02:05 AM

That is very unusual to see 0 NitrAtes. I've only experienced that in a well planted tank.

My only thought is, what sort of dechlorinator are you using? Certain one's such as Amquel +, will give inaccurate readings.

Skyrmir · 06-12-2005, 02:19 AM

I'm using Aquasafe from Tetra when I do my water changes, but I haven't changed the water in about 4 days and I've had a nitrate reading up until today.

BrianNY · 06-12-2005, 05:52 AM

I suspect your test kit is suspect. See if your lfs will verify your readings.

Skyrmir · 06-12-2005, 12:54 PM

Just tested it again today and the nitrates came back up, a hair lighter of a shade than 5ppm on the chart, but at least it's showing now. I really hate unexplained stuff like that. I could see if I had some algea going on that was sucking it up, but there's not so much as a speck that I can see.

Has to be some in there though, stealth pleco has gotten bigger since I got him.

Skyrmir · 06-13-2005, 06:28 PM

Ok I think I might have semi solved the mystery..maybe... The only thing I can think of that could be soaking up my nitrates is the algea tabs I've been dropping in for my Pleco. Being the stealth fish that he is, they sit in the tank until the lights go out...then mysteriously disappear overnight.

The reason I'm thinking this is I had a slight Nitrate reading yesterday, dropped in a tab for the pleco, and the nitrates went poof again. The algea tabs are the only even remotely plantlike thing in the tank.

Does anyone else use Wardley Algea discs from Hartz?

TankGirl · 06-13-2005, 06:31 PM

The disks are not able to uptake nitrate, or any other nutrient as they are processed food and not alive. They will contribute nitrate to the tank, if anything.

I would personally not worry about nitrate at all for now. I'd monitor ammonia and nitrite, and do weekly partial water changes assuming zero levels of the two, and that ought to take care of things just fine.