Nitrate refuses to come down....

[mpomfret]

My tank has been running for 4 weeks now. Ammonia and nitrite are both 0 after peaking around 0.25; pH=8.2; SG=1.023; 78<=temp<=81. I have a small clean up crew and 2 clowns, all of which were added after the ammonia and nitrite readings returned to 0. I also have some macro algae in my sump. Nitrate started around 10 pretty much at day 1 and is now hovering close to 20.

My water source is an RO/DI system I bought from Buckeye Field Supply and all the nitrogen params test 0 on its output.

So the question is: Why won't nitrates come down ? I have done a couple of small water changes (<10%) in the last week. But as Bertoni pointed out a couple of weeks ago in a similar thread, a big water change will work short term, but if there is an underlying cause, nitrate will come back up.

I have read several times that bio-balls will create nitrogen problems over time. I am not using bio-balls, but I do have a filter sock in my sump and sponge filters on the inlets to my return pump and the 2 powerheads in the main tank. Could the problem lie there ?

Matt

 

[kentrob11]

You should have waiting until your nitrates hit Zero before adding anything to the tank...Watch it for a few more weeks and it should come down gradually....

 

[bertoni]

The filter sock and the sponge filters both can function the same way as bio-balls in terms of producing nitrate. They should be cleaned very regularly if you want to use them.

The tank is still very new. I wouldn't worry about nitrate for a couple of months yet. For whatever reason, denitrification seems to be the hardest part of the filtration to get going.

 

[PatMayo]

I agree wait. My tank has been up around 62 days now. I use the sponge filters on my return pump and I have to sponge filters on a air filter for my QT tank.

I started off with nitrates in my tank as well. They finally dropped to zero at about 45 days. I change 8 gallons of water each week without fail. I change the filter on the return pump but don't touch the filters for the QT tank. I don't use filters on the powerheads but I do use some filter material in between one of the bubble traps just to keep any microbubbles that may find there way to the main display. I change those as well every weekend.

It may sound like a lot of work but I only devote 1 1/2 hours to cleaning the tank every week. That's not bad. I still have zero nitrates. Be patient and give it time.

Regards,

Pat

 

[mg426]

I run a pretty well stock reef. I had a nitrate problem 20ppm a good while back. i cut down the feedings, ditched the bioballs, bought a new skimmer did lots of water changes. nothing worked. Finally set up a refugium with a DSB. Was a pain to do cause I was short on space under the tank. I set mine up above the tank with a gravity/siphon return. waited, waited some more, waited some more. Finally 6 weeks after the fuge, bingo zero nitrates. i cant say for certain but my best geuss is the sand bed just needed time to mature. no more nitrates no more algae life is good in reef land.