High Nitrates, Please Help!

[surfergirl]

Hi All,
I have a 55gal tank, DSB, wet/dry w/bio balls,5 fish and 13 crabs. The nitrite level is 0, ammonia is 0, PH and salinity are fine but I can't seem to get the nitrate below 80. The tank is 1 year old. I do frequent water changes, every 2 weeks (15 gals). Yesterday, I changed out 20 gals and today the nitrate is still at 80. I have added a nitrate sponge about2 weeks ago with no changes. Please help me! I don't know what else to do. I'm concerned about my crabs. They aren't dead but not as perky as they used to be. My LFS is employed with idiots and there isn't another within an hours drive.

 

[beth]

It's the wet-dry filter and the bioballs. How deep is your DSB and how long have you had your tank setup? What are you using for water circulation and how much LR do you have in your system? Are you using a protein skimmer?

 

[fmarini]

Surfer:
so how much do you feed and how often? Does your new saltwater have nitrates as well(do you use RO/DI?)
You need to identify where the nitrates are originating from to slow them. AS Beth mentioned the wet/dry is one of the culprits, but i would also suggest to you that you need to reduce feeding, and keep up the 20gal water exchanges. Do you have a skimmer as well? An excellent skimmer (no seaclone) will remove a fair bit of organics before it becomes waste.
Can you identify a source of the nitrates?
frank

 

[surfergirl]

Beth....What do I do with the wet/dry, bioballs? How can I tell if they are the culprits? My DSB is about 2 inches, the tank has been set up for 11 months, I use power heads for water circulation, I have about 200lbs of LR and no protien skimmer.
Frank....I feed frzn brine shimp twince per day, and I do make sure they eat what I feed them. I just put in a little bit until that's eaten, then a little more, when that's gone then a little more. I make my own salt water out of tap. Where or how can I get or make an RO/RI system? My LFS tells me I don't need a skimmer yet. Is this not true? Should I get one now? I'm not sure what the source of the nitrate problem is. I need guidance on where and how to start to identify and then cure hte problem.
Thanks for all your help!! I'm new at this...can you tell!!! ;-)

 

[tvan]

Did the LFS get the same test resaults on your water? ie Have you ruled out your nitrate tester, Water source, check for nitrates in the water you add. HTH Tom

 

[beth]

Sorry to say, but you have an ineffective DSB. The very min. requirement for a DSB [deep sand bed] is 4". 2" just cannot function as a DSB. What type of substrate did you use for the sand bed? Brand name or grain sizes? What do you have in the way of detritivores in the sand bed?
What type of media/filters besides the bio-balls do you have in the Wet-Dry?
Take a reading of you water source prior to mixing salt to see if you are getting any nitrates from your source water [likely not, but perhaps].
If you want to establish a true DSB, I'm afraid you have your work cut out for you. However, we're here to help you if you decide to go that route.

 

[schreff]

My nitrates in my 55 gallon tank wiyh 4 damsels was 80 to 100 mg/l. the tank is 6 mos old. So I tested my tap water and there it was 45 mg/l, so I now buy water from my work (lfs).Now the nitrates are 15mg/l, but I only change 5 gallons a month (till I get better fish). Hope this helps.
-Jeremy

 

[pancho]

you might also wanna change about 20g of your water and like what was suggested earlier cut down on the feeding as well. What i found that helps alot to is that if you add salt water bio=zyme it cuts down on the nitrate as well and add prime with each water change as well

 

[surfergirl]

Beth....How can I increase my DSB to 4" without creating havoc? I'm willing to do the work. The live sand I got came in bags from the LFS I don't remember the brand name or grain size.
The type of filtration I use is filter floss, charcoal and now nitrate sponge.

 

[justinl]

Actually you can get away with a slightly shallower sand bed by using a very fine grain oolitic sand (I'm not just repeating what I've heard, I've actually tested this out.) At the very least I'd say add another inch of just oolitic. It will cloud your tank (just make sure your powerheads are off when you're doing it) but it should settle within a few hours if you use a plasic cup to scoop it from the bag and carefully pour it onto the existing sand bed. If you have a siphon I'd clean the bed first (just the surface of the bed- don't stick the siphon in the sand) to get rid of the poo and such before putting down the oolitic. Eventually the oolitic will sink to the bottom of the bed.
Also, invest in a protein skimmer. You can get a used Prizm for a decent price which will work on a 55.
One more thing you can try that has worked for me in the past is Seachem de*nitrate, even though you said you had tried another nitrate sponge product. Are you using Kent Nitrate Sponge? I notice that it says several weeks will be required to see an appreciable drop in nitrates, whereas with de*nitrate I noticed a drop in 3 days, which is what the Seachem web site said whould happen.