My losing battle with nitrates...

[Reef This]

Well, there is a million nitrate posts all over RC but I still cannot seem to get them down enough to start adding SPS, and to put the effort into building my halide hood.

Tank is about 18 months old, 3/4-2" sandbed (depends on where the clown goes, she throws it everywhere). Eheim 2227 with no media in it, just used for flow, 24" aquafuge with feather calurpa and chaeto - about 80# of live rock, Remora Pro with Mag 7, about 700gph of powerheads in the tank as well.

Now, I'd really reduced my feeding, as I was overfeeding pretty substantially. I did a good cleaning of the substrate as I don't want any of it to go live. There is no sand under the liverock that can go live, as it sits on bare bottom. Whatever it filled in isn't probably anymore then 1/2 inch deep.

My nitrates were around 10-15 and they went up this week after the cleaning. I guess that was to be expected. I'm doing another 10g change today, and will test again late this week.

I've done pretty much everything I can, but any advice or issues with what I'm doing, I would appreciate any help.

-- Joe

[Randy Holmes-Farley]

My suggestion is to pick at least one method for exporting nitrogen and use it. Skimming helps, but is often not 100% successful. Alone, it wasn't good enough in my case. The best method, IMO, is to grow and harvest macroalgae. Deep sand beds are also useful in this regard. Water changes are not very useful for nitrate reduction, IMO.

This article details many nitrogen export methods:

Nitrate Issues
http://www.advancedaquarist.com/issues/august2003/chem.htm

[DonJasper]

Originally posted by Reef This
I did a good cleaning of the substrate as I don't want any of it to go live. There is no sand under the liverock that can go live, as it sits on bare bottom.

Sounds like to me that you might consider the need to vacuum out the dead stuff that falls to the bottom before it breaks down. I've been trying to get someone to own up to a cleaning frequency, but have been unsuccessful (so far). I'd guess vacuuming the sand once a week might be a good place to start, and then go up/down from there depending on nitrate levels.

[bhujang]

What is the gallonage of your tank? You should have 1kg per gallon, I seriously over feed, and use 1kg per gallon and since my tank cycled, which took 6 months my nitrates have been on 0 with no spikes. Are you using good LR,? Very light and porous? I run my skimmer 24/7. Even when things die like the occasion fish that I cant reach at the back or an angel wing clam the tank can handle it and the nitrates are still 0. How many fish do you have in the tank? i.e. how big is the bio load? What test kit are you using and how old is it? What clean up crew you got? Again that should be in ratio with the size of the tank.

[beaslbob]

Reef:

regardless of whatever else you are doing, your nitrates will go to 0.0 with sufficient plant life. So my analysis you just don't have enough plant life --yet. At 10-15ppm seems you are close though.

[SPC]

Originally posted by Reef This
Eheim 2227 with no media in it, just used for flow,

My nitrates were around 10-15 and they went up this week after the cleaning. I guess that was to be expected. I'm doing another 10g change today, and will test again late this week.

Hi Joe,

Your Eheim isn't storing detritus in the bottom of it is it?

If your nitrates went up after cleaning the substrate, then IMO thats a pretty good indication that at least part (maybe even most) of the problem is in this area. With such a shallow sand bed you are not going to get the denitrification benefits that a DSB would produce, and yet you will have a place to trap detritus.
Steve

[bhujang]

Sure 10-15 ppm isnt high at all and many corals will be fine at that level...