Nitrate problem

[marfa59]

I have a 110 gal. tank with 11 discus, 1 pleco and 3 clown loaches. It has been up for 13 months. The tank has a bare bottom and I have one Marineland penguin and one Marinland emporer, both have a Max III sponge attached. In the second filter slot of the Emporer I have ceramic rings. I have one bubbler in the tank. I do a wc every 4 days. About 2 months ago my tank went through a minicycle, I have no idea why. Ammonia and Nitrites are now 0 and have been for 3 weeks. The nitrates are 10 and sometimes look to be a little higher. During the minicyle I have been doing a wc every 1 to 2 days. I have always kept my tank very clean and I don't think I over feed. The food is completely eaten within 5 minutes. I can't seem to get the nitrates to go down. I don't know what to do. Any suggestions?
Connie

[Chad Hughes]

Connie,

Your Nitrate reading is not bad and is a common byproduct of the nitrification process. I wouldn't worry about it too much.

I am assuming that this is something new and that you used to be able to take readings with undetectable nitrate. If that's the case, has your tap water changed? Nitrate readings out of the tap are not uncommon.

Hope that helps!

[marfa59]

Hi Chad,
The tap water hasn't changed as far as I know. I use mostly ro water with very little tap water. Up until the minicycle that I just went through the nitrates have been undetectable. At what reading should I worry?
Connie

[Chad Hughes]

Hi Chad,
The tap water hasn't changed as far as I know. I use mostly ro water with very little tap water. Up until the minicycle that I just went through the nitrates have been undetectable. At what reading should I worry?
Connie

Connie,

Well, and this may seem like a dumb question, but have you tested your RO product water? Is it possible that your filters need changed or are you buying RO water? I would test it before it goes in to the tank.

If for some reason your system just has increased nitrate production, it could be anything. Food is a big one. Have you changed diets? Are your filters clean?

I would begin to worry if you exceed 20. With your water change frequency, I can't see them getting as high or higher than 20 unless you are power feeding and not cleaning debris daily. I have heard of breeders having nitrate readings of 30+, but I would not recommend that.

Best wishes!

[Darrell Ward]

To expand on what has been said above, if you are using bio wheels with those filters, that could very well be your source of nitrate. Bio wheels tend to become major nitrate factories after awhile.

[marfa59]

Hi Chad,
I buy my ro water but tested it anyway. It is 0. I feed 2 small pinches of Omega one pellets in the morning and 2 cubes of frozen blood worms in the evening. This is the way I have been feeding since the beginning. Darrell suggested it could be the biowheels. Should I replace those one at a time?
The test this morning still reads 10. I won't worry if you think it's ok. I just can't figure out the cause.

[mmorris]

Your nitrates are perfectly fine! Don't worry about it! I am always a little suspect when people post "0" nitrates.

[Jhhnn]

Your nitrates are perfectly fine! Don't worry about it! I am always a little suspect when people post "0" nitrates.

I'm with Martha. Nitrates are the end product of the nitrification process- their presence indicates that your biofilter is working as intended. They're also impossible to remove except with plants, water changes or (supposedly) some specialized adsorption resins, which I haven't tried. 10ppm is quite low and entirely acceptable, as I understand it. My BB tanks routinely run 2X-3X that amount, and my discus thrive. I feed a lot, and change a lot of water, 50% or more on a daily basis. Some European keepers report success with much higher nitrate levels than that, because their tap water contains high nitrates in the first place.

If you're growing out young discus, the feeding regimen you describe really needs to be increased for them to reach full growth potential... imo, anyway.

[marfa59]

Thanks guys. I'll quit being a worry wart!!

[Darrell Ward]

For what it's worth, lots of people have nitrate in their source water, including me. I have been keeping discus in it for years without a problem. Unless one has an extremely high percentage of nitrate present in the water, it's not going to hurt the fish. To answer your other question, yes you can change out those bio wheels one at a time, but be careful. If they are a large part of your bio, you will have to monitor the water carefully, and be ready to act in case of a spike in ammonia. It will probably take a week or two for a new wheel to cycle in a established tank.

[flyman767]

I've done 50% w/c every day for a week when my fish were ill and never did the nitrate's drop below 10ppm. If you were recording "0"ppm, maybe the protocol was flawed or the test was invalid.