Nitrates at 40

[Darth-Tater]

Ok I have been battling my sliding downhill tank for about two months. It is 100 gallons. I have been doing 25% water change every two weeks(25 gallons at a time) Got rid of the big Bad Mother crabs(thanks Carl & V2k) Got rid of the chocolate chip star. Amonia are non existant, Nitrites are at 0 but. Nitartes are at 40 :o . I have about 150 lbs of live rock and 60 lbs of live sand. What can I do to bring them down. I am getting ready to change to a bigger proclear wet dry tomorrow. I have had it for a while.It should provide more circulation. It has bio balls in it. Now, I know this in it's self will spark a great debate. But, I do need help it seems everything in the tank is going. My xenia has bit the big one. At one time it was growing like crazy. Any ideas? I did switch to IO a while back.

David

[Edk]

I've had really good luck with a product called AZNO3. Marine Depot http://www.marinedepot.com/aquarium_additives_azno3.asp?ast=&key=
carries it as does Aquadome in Austin. Took about 2 weeks to drive nitrates from 30 to 0 in my 180.

[demodiki]

What type of skimmer do you have? What kind of livestock and what is your feeding schedule? Are you cleaning your sandbed with every water change? Are you using a wet dry now?

[GaryP]

High Nitrates are caused by the lack of a sufficient denitrifying bacteria population. While your live rock is helping, denitrifying bacteria primarily live in a deep sand bed. 60 pounds of sand in a 100 gal. doesn't sound like enough to me. I typically recommend at least 4 inches of sugar fine sand as the minimum for a good deep sand bed. If you are concerned with sugar fine being blown around, add a 1" layer of special grade on top of it.

The other thing you can do is put in a refugium. A healthy population of macro algae will help soak up the nitrates being produced in your tank.

A wet dry does produce nitrates, but that isn't necessarily a bad thing. It is supposed to do that. The problem isn't in the production of nitrates, the problem is in what happens after that step in the nitrogen cycle. Other steps you can make to help out include: changing out a physical filter at least once a week, skimming heavily, the use of something like Bioslab to offer the denitrifying bacteria another place to call home, and maintaining a healthy population of detritivores such as micro hermits and nassarius snails to clean up any left over food.

[NaCl_H2O]

David, use the "Calculators" link on the left for sandbed depth calculation. Example: a 72x18 tank base with a 4" sandbed is > 300 lbs of sand. You have seen my tanks, I have almost 1,000 lbs of sand in my three tanks!

Also, a DSB will take some time to buid up the bacteria needed to work on the Nitrates, so even if you add more sand keep up the more frequent water changes for a few months.

Also, I NEVER "clean" my sandbeds, inhabitants stir the surface around somewhat, and I will spread out a "Hill" created by the sifters, but I never "Stir it up" - that destroys the bacteria.

Gary's advice on a fuge is also a very good idea if you have room. Also, I have a HUGE Wet/Dry on my system, my Nitrates have been 0 since the initial cycling a year ago.

[GaryP]

Also, I NEVER "clean" my sandbeds, inhabitants stir the surface around somewhat, and I will spread out a "Hill" created by the sifters, but I never "Stir it up" - that destroys the bacteria.

It actually doesn't kill them. It does cause them to shut down and sit there waiting until the proper low oxygen conditions return before they become metabolically active again.

[gjuarez]

Sorry to highjack the thread, I just have a quick question for Gary. Gary, what is a good book to read about denitrifying bnacteria? I would like to know more about this.

[Darth-Tater]

Thanks to everyone who has a suggestion for me. I have just changed out the wet-dry to a bigger one I bought this summer from smelly Brad. Lots of crud in the old one. Will do another 25 gallon water change this evening. water is mixing as I type. Last question. How do I run carbon and what type should I use,how nuch?

Thanks

david

[GaryP]

Thanks to everyone who has a suggestion for me. I have just changed out the wet-dry to a bigger one I bought this summer from smelly Brad. Lots of crud in the old one. Will do another 25 gallon water change this evening. water is mixing as I type. Last question. How do I run carbon and what type should I use,how nuch?

The wet dry will probably not make any difference. Like I said, its doing what its supposed to do.

As for carbon, I like the granular coal (anthracite or lignite) based carbons. I am currently using the Triple Carbon Brand from CB Pets even though its not granular. Different carbons are going to be better at absorbing different types of organics. That's why I like using a mixture like Triple Carbon.

[GaryP]

Sorry to highjack the thread, I just have a quick question for Gary. Gary, what is a good book to read about denitrifying bnacteria? I would like to know more about this.

Here you go:

http://www.aquabuys.com/page/aqb/CTGY/z2i

http://www.pet-animal-book.com/animal-care-pets-fish-aquariums/004/ron-dr-shimek-sand-bed-secrets-the-common-sense-way-to-biologic.htm

[GaryP]

Denitrification is accomplished by Pseudomonas bacteria and others. This process is anaerobic, occurring in the absence of oxygen. Obviously, denitrifying bacteria cannot live on the oxygenated surfaces on which nitrifying bacteria live. The only places where denitrifying bacteria are found are where there is a source of nitrate but no source of oxygen. In an aquarium, anaerobic activity is most likely to occur in a deep layer of gravel or sand with no water flowing through it. Anaerobic activity can also take place in a clogged filter, where nitrate is available but water is moving so slowly that it loses its oxygen before it travels through the filter.

[JimD]

Turn your wet-dry into a refugium and kiss your nitrates goodbye. Also, make sure you have plenty of flow, no dead areas for detritus to collect and decay, periodicly use a turkey baster to aggitate any detritus from the rock surface and caverns immidiately before a water change. Do regular maintenance on any filter socks you may be using,, etc. etc.....