all good except Nitrate, how do I fix?
 

so did some rearranging of the LR in my 220gal DT about 3 wks ago and did a water test today. tank has been up and running at least 6 yrs, live rock, various fish, few mushrooms. I don't seem to have any algae problems (It takes nearly 5 days for any meaningful build up on the acrylic). fish are fat and happy, snails aren't moving much even at night. I want to start adding SPS and LPS but now a bit worried. thank you for your help!!

salinity 1.026
Mg: 1400
Alk:9.1
cal: 500+
PO4: .04 mg/l
NO3: +32!!!!!

what could be causing the high NO3 and what do I do about it?

Following. Same situation here. No sand bed.

Rearranging of the rock is my guess. Same thing happened in my tank when looking for a missing fish a couple month ago.

Any carbon dosing or nurtient export?

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I agree that rearranging rock can cause such problems. I probably would wait, but a few water changes might speed the process. You could consider adding some form of carbon such as vodka or vinegar, if you're interested:

http://reefkeeping.com/joomla/index....arine-aquarium

If no3 has always been on the lower side I would just wait it out. That is assuming moving the rock work is what caused the spike. If u start changing things u may end up causing more harm then good. No3 at those levels isn’t going to bother anything u have in the tank but a couple big water changes should drop it down quite a bit if u are worried.

Whats missing is what was the nitrate prior to the rock moving?
If its was lower then you might just need to wait it out..
If not then you simply don't have enough export to match your import and there are numerous ways that people attempt to increase their export from carbon dosing to macroalgae/turf scrubbers/sulfur denitrators/increased water changes/,etc...

Carbon dosing will bring the nitrates down. I was skeptical about using vinegar, and vodka etc. So, if like me you want something tested in a lab, have a look at Red Sea's NO3:PO4-X. I have found this to be an excellent product, and you can really dial it in to get the exact level of nitrates you desire (which isn't always '0').

thank you all for your replies!

i dont have a measurement of what NO3 was prior to moving the rock work. but if i understand what some of you have said, i basically do not have enough "filtration" to remove the waste and/or am feeding too much. is that a fair summary? please correct me if the summary of potential fixes is wrong:

1. add more live rock to increase filtration
2. cut back on feeding
3. water changes
4. use one of the products noted in the posts
5. use the skimmer more (currently only have it on 1 day a week)
6. others?

You can add an inert product like Siporax to the sump for denitrification.

OH -- Skimmers are meant to run 24/7

vinny,

thank you for your reply & suggestion!

i dialed back on skimmer use because i was afraid of removing too much and making the water too "clean". i should do a better job of testing to ensure i'm not making the water too "dirty".

http://reefcentral.com/forums/showthread.php?t=2656685
Read the last post by sleif --
Enlightening on skimmers.

Red Sea's NO3:PO4-X is Ethanol alcohol (same as vodka) and acetic acid (vinegar) with a bit of methanol alcohol. The methanol is to make it unfit for human consumption so it can be sold to minors. Oh, and making your own mixture is a whole lot cheaper.

Nitrate is the final step in the process of converting ammonia. It either needs to be removed or consumed (carbon dosing). I have an ATS for export and also do carbon dosing. I feed a lot - the equivalent of 103 gram cubes/day, mostly from a full sheet (64 sq inches) of nori.

Gary - Do you have a recommendation on dosing, and it sounds like you're mixing vodka and vinegar together (?), if so, what ratios do you use?

I am using a 50/50 mix. I started out a long time (2-3 years ago) with just vodka and switched to all vinegar as vodka is said to contribute to cyano. I than went to 70/30 (vinegar/vodka) (nopox).

Here is a good guide to starting carbon dosing. If using vinegar multiply the vodka dose by 8.

http://www.reefkeeping.com/issues/2006-02/rhf/

I agree with keeping the skimmer running 24x7. Adding more live rock would be a solution if the nitrate problem seems to be a long-term issue. It won't help in the short term. I'd probably try a few water changes and wait a bit, but carbon dosing (vinegar, vodka, NOPOx, etc) is reasonable to try, too.

32ppm is a bit high for some sensitive sps ,IME ,but won't harm anything you have currently. I'd wait it out with a a few water changes. Personally , I've used carbon dosing( vodka and vinegar ) for over 8 years with 24?7 skimming to keep NO3 under 1ppm and P04 around 2/3ppm even with heavy feeding. A sulfur denitrator is another option for nitrate control I've used with success before going to carbon dosing.

While the real chemists can chime in and correct me, I wonder if the tank is phosphate limited and not allowing nitrates to come down naturally. My recent research shows shooting for a ratio of 10ppm N to .10ppm P seems to keep everything happy and in check. Assuming the Phosphate reading is correct (.04 falls within the acceptable error range for some readers) the tank could actually be at 0 phosphates. I am learning the hard way that a consistent reading of 0 phosphates isn't a good thing. At least not for me and my system (and a lot of others too.)

Yes. Its redfield ratio of N:P. I learned the hardway too. I was using rowaphos too much that my po4 is 0 and wondering why my no3 is above 100 even i have carbon dose. The i came across this redfield ratio and changed eveything. So i did 60% wc and no3 is 2ppm with phos 0.03. No phos remover till today with almost 1 cube mysis everyday.

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The Redfield ratio doesn't quite apply here, but for bacterial growth (or any form of growth) to consume nitrate by incorporating it, the organism will consume some phosphorus, likely from phosphate. On the other hand, denitrification occurs when microbes convert nitrate to oxygen and nitrogen gas, and it will work without net consumption of phosphorus. So live rock can perform denitrification without phosphate.

I doubt a phosphate deficiency is occurring in this tank with a 0.04ppm reading even though accuracy may be an issue. When a phosphate deficiency comes up a remover like gfo is usually in play.
Nutrient balance ( carbon/nitrogen/ phosphorus see Liebig's law) is important; the Redfield ratio (116 C to 16 N to 1 P)is an en masse measure of these nutrients in the sea and the ratio for may vary form organism to organism. Also as noted , nitrogen removal can occur via anaerobic bacterial activity which releases N to form N2 gas which bubbles out of the tank which can skew the ratio in a given tank toward lower N.

In theory organic carbon can be lower than desired limiting the growth of heterotrophic bacteria which can't get it from CO2 as photosynthetic organisms can. Growing these bacteria is the reason for dosing organic carbon( vodka ,vinegar et al).As they grow and multiply they take up P and N along with the increased available organic carbon and they and their waste products are exportable via skimming. Sometimes nitrogen deficiencies can occur when carbon dosing ,rarely if ever a PO4 deficiency though. None , in my 8 plus year experience with carbon dosing anyway.

I am dosing 50/50 vodka/vinegar at 35 ml/day to my 165 TWV system. I feed very heavy = particularly Nori and romaine), the equivalent of 7 3g cubes. I also have an ATS. Nitrates have dropped to 1 but PO4 is starting to rise, test at .07 today. Is this occurring because of the ratio?

I don't think so if it's truly 1ppm . You could try a bit of sodium nitrate,say 1/3 tsp for your 200 gallons to see if it helps bring the PO4 down. O.07ppm PO4 isn't terrible and might adjust on its' own