I need Help

[RomaFan]

Hi everyone, I could for sure use some help.I have a biocube 14 that has been up and running for over a year now, its a berlin setup with sps and two percs. The Sand bed is about 3 inches deep, with 25lbs of live rock. I have a lfs back pack skimmer and radon lighting.
Parameters a re as follows:

SG35 ppt
Temp 73F
Cal 500 ppm
Mg 1500 ppm
Alk 10.2 dKH
Nitrites 0
Nitrates >60ppm
Ammonia 0 ppm
Po4 0.03 ppm

I have been battiling very high nitrates for about a month now, I have done every other day water changes, I have been using red sea NoPOX, to no avail. I have looked for dead debris and not standing water, there is very good flow. I am at a lost with this. I have been thinking if this could cause my problem:

I have a pistol shrimp and he is moving sand everywhere every night. Keeps digging and making tunnels, and with a small footprint can this cause the high nitrates? Needless to say my sps are not very happy and neither am I. Any suggestions would be appreciated.

[craigwmiller]

What is your fresh water source?

If you are using an RO/DI unit, when was the last time the filters & DI were changed? And what is the TDS reading after the RO and then after the DI stages?

[sphelps]

The tank is only 14 gallons so it would be really easy just to change 100% of the water. This is a common approach for small nano aquariums and can be used as a long term maintenance plan or a temporary solution for nitrates and other contaminants.

Some links you may find useful
http://www.advancedaquarist.com/2010/4/aquarium
http://www.reefkeeping.com/issues/2005-10/rhf/

Also I'll note your temperature is quite low for an SPS tank. In addition with lower temperatures you'll likely see more fluctuations due to external temperatures.

[RomaFan]

I check my ro/di water paramters before I mix the salt and after with neglagable parameters, so thats not where its coming from. Changing all the water? how would my corals do under those circumstances?

[craigwmiller]

Most corals can handle significant amounts of time out of water. Walking/snorkling the beach in Hawaii personally confirms this -- many corals are exposed to the air/sun for HOURS each day.

I would just make sure you have the make-up water ready, and then just do it.

IMPORTANT though, is not to disturb your sandbed - since anything in there would get stirred up.



Regarding the deep sand bed releasing nutrients, this is likely the case also. There are many thoughts on the matter, but personally I prefer a shallow sandbed (1-1.5"), which I then have a sleeper goby to constantly stir it up to keep things clean and nutrient-free. If you are interested in removing/cleaning your sand -- I would recommend doing it SLOWLY so not to disturb it too much and release many nutrients too quick. Say remove a cup every few days/etc. If you do it gradually enough, you should not have an issue.

[Proteus]

Did you keep the foam inserts in back of tank if there is any. If so organics fills up the foam and will make nitrates.

[RomaFan]

Everything is removed from the compartments in the back. I only have a heater and intake and return from the skimmer. The only thing that is really disturbing the sand bed is the pistol shrimp.

[JmeJReefer]

that sand bed sound suspect. DSB's have inherent problemo's.....