Constant Nitrate levels

[tbates]

Relatively new 55 gal tank (has been up and running for several months) has rarely seen a nitrate level below 12mg/l and is typically between there and 25. Have been doing regular water changes - as much as 10 gal per week, and up to 15 gal per week, with no significant reduction in nitrate level . Ammonia and nitrites are at 0 or close to it .

Here's my environment:
55 gal tank
Emperor Bio-wheel filter (using only the carbon & mesh filter inserts)
Remora Protein Skimmer w/maxi-jet
45 lbs LR
CC substrate (2-3 inches deep)
2 False Percula clowns
2 yellow tail Damsels
Cleaning crew (2 brittle stars, 25 red leg hermits, 25 snails, 4 emerald crabs, 1 sally lightfoot crab, 25 dwarf blue hermits)

(Note that I cannot locate any of the blues. can't say if they're dead or just hiding really well).

No significant algae problem, although I get white "dots" on the glass.

Feeding once per day - rotate between flake and brine shrimp. Stars get fed clams or mussels twice per week, occasional red algae piece for variety.

I do NOT agitate the CC substrate when doing the water change.

What am I missing as far as getting the nitrates to drop?

Thanks for any hints...

 

[fishfreek]

Emperor Bio-wheel filter (using only the carbon & mesh filter inserts)
CC substrate (2-3 inches deep)
I do NOT agitate the CC substrate when doing the water change.

In my view there are the three things that are keeping your nitrates up.

First the bio-wheel is an excellent method of removing ammonia and nitrite but will hold nitrate to some degreee because its a highly oxygenated enviorment and a low oxygen enviorment is needed for nitrate removal.

Having such a deep CC bed will trap uneaten food and fish waste. Since CC is larger in size than sand water also flows thru it better maintaning a higher oxygen level than an equivlent deep sand bed.

And by not agitating the CC when doing a water change your not really getting to the source of the nitrate. On your next water change use yoru syphon and gently stir top 1" or so of the CC substrate. You probably will see a significant amound of detrius come up out of the substrate and into your waste bucket.

Once you do your water change that way I suspect your nitrate reading will be lower. I do have to question how low you will be able to keep your nitrate given the CC substrate and the biowheel.

 

[tbates]

Thanks...I'll give the substrate a good sucking on the next water change.

A couple of questions based on your feedback of

I do have to question how low you will be able to keep your nitrate given the CC substrate and the biowheel.

Should I disable/eliminate the bio-wheel? It's giving me some level of current, but I suppose I could just go to a power head. Will the LR and/or LS (second question) give me sufficient filtering without the bio-wheel/filter combo?

Would adding LS on top of the CC (or partial removal of the CC and replacement with LS) help with the nitrates?

I appreciate your help since I'm kinda new at this...

 

[Guest]

Should I disable/eliminate the bio-wheel? It's giving me some level of current, but I suppose I could just go to a power head. Will the LR and/or LS (second question) give me sufficient filtering without the bio-wheel/filter combo?

I would recommend getting rid of al the media and just using the Emporer for flow. Get a couple of powerheads, LS and LR, and you will have all the filtration you need.

I do not have any filter media running in mine. all I have are 2-300 gph PH's and 1 500 gph return pump and LS and LR. The water is crystal clear.. My Nitrates are about 5 meg/L now...I have given up the protien skimming as well. I do not recommend that if you are a beginner though.. It has taken a lot of work to get the tank where it is, and it is watched carefully for signs of trouble.

 

[tbates]

Thanks to Tim & FishFreek...

I suppose the big question now is...

Should I pull the CC and replace it with LS, pull some of the CC and top it with LS, or just put LS on top of the CC afer siphoning it?

I'll get some PH from the LFS and plan on re-arranging the LR so that I can siphon some of the areas that are behind/under it and relatively inaccessible.

Do you think this work will stress the critters enough that I should temporarily remove them from the tank?

Thanks again...

 

[ReefRaff]

I'll go out on a limb and say If you have 2-3" of cc, then pull an inch or inch and a half out and add LS till you get to about 4" min. My .02

 

[Guest]

It will be a pain in the rear, but, I recommend to split the tank in half and place all of the rock work you can on one side, scoop out slowly, one half of the CC, and replace it with 4inches of CarribSea Aragonite reef sand, and 2 lbs of LS from the LFS if possible. Then move back the rock work. Wait a week or two, and then do the other side the same way. This will ensure you allow the bio-diversity to build back up and not freak out... Once you get the CC replaced, and the 4 or 5 Lbs of LS seeding the Sand, make sure you get the LR up to 1.5 lbs per Gal. This will ensure you optimum filtration for your tank. The sand will become alive more than you can imagine, within a few months..Make sure if at all possible, to get the LS from an established tank at the LFS. If not, the LR you already have may be enough to seed the new sand. The Aragalive sand sold in a commercial bag, is not really worth the money it costs. Good luck, and keep the faith..

 

[tbates]

I think that I'll just pull the CC and lay down a DSB of about 4". I'm assuming that pulling the critters and placing them in a holding tank would be the best strategy to help keep them from croaking (since it will, I believe, take a day or two for the sand to settle and the water to clear).

What diameter sand would be best? I've seen everything from 4mm down to 0.18.

Thanks from a beginner...

 

[fishfreek]

Sugar grain size.

Look at your local hardware store for yardright sand. Its argonite based and you can get it for like $4 for 50lbs. A far cry from the $1 or more per lb the lFS wants for bagged sand.

If possible add an inch or so of live sand on top of the dry sand.

 

[Guest]

I would say no bigger than 2mm....

I don't think you will want to pull it all the CC at once, because you may start the tank cycling again... You may get a little with the half and half method, but, it may be too much to do it all at once...If the cycling doesn't bother you and you can give the fish a home for a few weeks untill all settles down, then by all means do it all at once... I am just mainly looking out for your livestock...