high nitrates

spider8u

New member
Hi i keep getting high nitrates my tank has been up for 2 months on saturday i did 65gl water change got my nitrates to 20 from 60 today i checked again and there back up to 40 so why i am getting high nitrates and what can i do to get them down. I dont have any fish in the tank just 100lbs of rock and 85lbs of sand i am useing a canister right now xp3 but i dont have any sponges in it just some cabon and LR and HOB skimmer this is 100gl tank thx

Salinity 1.025
Temp 78/80
pH 8.4
Ammonia 0
Nitrate 40
Nitrite 0
Alkalinity 11.5 dKH
Calcium 400
Phosphate 0.00
 
Keep up the water changes as you may still have a lot of die off from the LR, it should level out in time.
 
I'd agree with meco, there. Also, if there is a good deal of die-off from the rock in the tank, make sure you're rinsing the canister out frequently, because even without medium in there, you'll collect a lot of waste in the carbon and that could contribute to a generation of nitrates.

By the way, if you aren't using RO/DI water, then you should test the nitrates of your source water to be sure that you aren't adding water with a high concentration of nitrates when you filled the tank and do water changes.
 
I agree with both meco65 and avi. Also make sure to clean any filter media on a weekly basis as these turn into nitrate factories if you don't. I would keep up the water changes on a weekly basis but I wouldn't make them so huge. 65 gals out of a 100gal system is a lot and you end up throwing away good bacteria. This can potentially prolong your tank's cycling process. I would wait it out and perform only 10% water changes on a weekly or bi-weekly basis until your tank finishes cycling.
 
Thx for the replys .Yes i am useing RO/DI water. when you say I would wait it out and perform only 10% water changes on a weekly or bi-weekly basis until your tank finishes cycling. So my tank has not finished its cycle? i thought when the ammonia is 0 and nitrite is 0 means the tank has fished its cycle. Also would putting some Purigen in my canister help out with nitrates thx

Also is it safe to put a clean up crew in the tank because i am starting to get brown stuff on the glass and sand
 
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IMO, you ought to wait a while longer to see if your water's nitrates reduce, taking the measures that we've mentioned. Using the RO/DI water takes that possible nitrate source out of the equasion so by waiting you'd see if there might be something in the rock that's generating the nitrates and as the rock becomes more and more effective, that should no longer be the case. I'd suspect that because the nitrates went up, as you say, after the water change that had gotten them temporarily down.

I wouldn't bother with Purigen, or any other chemical medium, and instead, just have a bit more patience and see what happens over, say, a week's time. The nitrates will most likely drop sharply (though, there is no way to say, with greater precision, how long it will take.)

I'm curious about your skimmer. Generally, hang-ons, I thought were rated for smaller tanks. Is yours working effectively?
 
I am a little farther than you at about 3 months, have cycled and have even added a few small items including the cleanup crew (most of which is gone for other reasons...not to worry). I still have a slight nitrate level of a constant 40 with no die off that my MB friend and I can find. I am going to try Purigen in a sump bag and see if it levels out toward the 0 mark. I clean the skimmer every day/day-and-a-haf. It now smells like a nunnery septic tank, not an animal-house one!!! Even after the cycle, you will have some die off (if it is anywhere as much alive as my LR)....I have asked the same here, and the best answer is "patience" ... :)
 
Well it depends on your definition of cycling. High nitrates are usually seen towards the end/completion of a tank's cycling period. If you keep performing major water changes your tank will have a hard time finishing the last part of the cycle since you're removing good bacteria. You can end up actually going back a step and end up with nitrites again. So I suggest you leave the tank alone and do minimal water changes and wait for it to build up enough nitrate eating bacteria. Nitrate eating bacteria takes much longer to reproduce than ammonia and nitrite eating bacteria hence why you want to do refrain from tinkering too much and let it balance itself out.

I'd wait for the nitrates to drop a bit before introducing your cleaning crew. Perhaps once they are below 20ppm on their own then I'd add the cleaning crew. When I say on their own I mean leaving the tank settle. Not lowering the nitrates by performing major water changes.

Make sure you keep your filters clean on a weekly basis.

Hope this helps...
 
Get a good skimmer to pull the junk out before it breaks down into nitrates. That would be my guess.
 
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