UV Sterilizers and Nitrogen Cycle

[dmweise]

I have been working to reduce the overall nitrates in my tank. My ammonia and nitrite levels stay unmeasurable, however, my nitrates generally stay at about 25 ppm.

I was wondering if a UV sterilizer would cause nitrates to increase if the sterilizer is left on all the time. At present I have a UV sterilizer in my tank plumbing and am wondering what the long term affects would be if I just left it on.

Also, how often should I test my water? I was thinking twice a week. I do weekly water changes.

[ErikH]

Oh yeah, you could have an issue. If there is buildup inside your UV, it can cause a ton of problems. Also, you really do not want to run one inline as the flow needs to be very slow through a UV. You need to check your manufacturers rating. You could run it off a tee I presume, but that would be too risky IMO. Get a small MJ and run it off there. Also, you need to replace the bulb every three months unless the bulbs have gotten a longer lifecycle.

[allan]

I know this doesn't help but one way to lower your 'trates is to cultivate red cyano... ever since my outbreak I have had no measurable nitrates. Of course if given the choice I'd rather deal with the nitrates.

[dmweise]

I will trying turning off the UV sterilizer for a while and see what happens. I have been running it straight for at least two months.

I have some cyano bacteria in my refugium. I guess it will help with that.

[dmweise]

I do not think I am feeding too much. My fish eat all of the food that I put in there and there is rarely any "leftovers" sitting in the rocks or on the sand bed after feeding.

[kkiel02]

Do you have room for a deep sand bed? Ping described how beneficial they are at this last meeting so thought I would throw it out there.

[Bill S]

To answer your original question: a UV sterilizer will add, nominally, to your ORP - which does oxidize organics. But I wouldn't choose it for just that purpose. You will do much better with an ozonizer.

[dmweise]

Do you have room for a deep sand bed? Ping described how beneficial they are at this last meeting so thought I would throw it out there.

I have a deep sand bed in my refugium. It is 3 or 4 inches deep.

[dmweise]

To answer your original question: a UV sterilizer will add, nominally, to your ORP - which does oxidize organics. But I wouldn't choose it for just that purpose. You will do much better with an ozonizer.

I have turned off the UV sterilizer for a bit. I want to see what it can do.

[dmweise]

I did some reading about the nitrogen cycle today. I was thinking that maybe removing the sand and plants from my refugium and replacing it with lots and lots of live rock, like all the way up to the water line. What do you think?

[allan]

Not an expert but this is what I've learned so far.

If you want a deep sand bed fuge, then you have to have at least six inches evenly across the bed. No lights will allow the sponges to grow and add to the filtration. The dsb of six inches will allow the benificial growth of bacteria at the bottom. You will eventually see a dark area about two inches from the bottom of the tank that will let you know the process has begun.

Macro fuge will pull the stuff out of the water that you don't need/want to include 'trates... but you will still be relegated to water changes (which have additional value of replacing minerals for your corals). With the macro fuge you don't really require the sand bed, but if you do have one I would recommend a couple of inches as you want to pick a direction and go that way, either dsb or macro. With the macro you need lights that will promote growth, and thus the removal of the unwanted stuff, and inhibit the sponges that will help clean the water. Plus, with macro you have to ensure you have adequate water passing through the greenery for maximum exposure.

The dsb in the dark combines the additional method called cryptic or crypt fuge. Cryptic doesn't sound right as it means something entirely different to me than what is implied, and that is a very dark area in which the sponges and other night loving creatures will dwell.

The sand will help promote the growth of the copes, mysis, and arthropods (I'm sure I either have these wrong or there are more) as they need somewhere to hide. The type of sand (large grain or fine) will help determine what kind of bug growth you have.

I have a macro fuge that spills over into a large area where I currently have a kinda deep sand bed but in the dark. I'm trying to cultivate the sponges myself but have not yet gotten an opaque piece of 'glass to block the light from the macro fuge section. The macro fuge area has these little bugs that are about a 16th of an inch long and thin, stars and snails... and a couple of mysis can be seen. The large fuge area has a huge amount of mysis allllll over the place swimming at all levels, stars, snails, and bristle worms along with what I can only imagine are arthropods (little hunched over fellows with about four or six legs pointing out at ridiculous angles).

Finally this area spills into an area that once held a filter set up. I've since changed that to a pile of LR. The water passes over the rocks pretty fast and thus I do not believe I am adding to the overall system what the paragraph below will indicate. I do however cultivate bugs in there that spill over into my sump and are swished back up to the display.

Filling your fuge up with macro, IMO, not a good idea. You're right about the added biological filtration that the extra rock will give you but in the long term you will have a wealth of detritus build up in the rock. Imagine why you want your display all open and exposed to current, thus getting rid of the 'dead spots'... and then imagine what you will have if you filled your fuge up with LR.

Anyway, just my two cents. I've only just begun to learn about the fuges so you might want to wait to see if I'm on target or if my shot group is loose. You should ping Pete, excuse the pun, for advice.

[hobogato]

nice allan, the only thing i would add is that the liverock will not do much for the last step in the nitrogen cycle - removing nitrate by absorption or changing it to nitrogen gas. you need some way to export the nitrate or it will build up.

[Bill S]

As Ace and Allan indicated above, most of us have nitrate problems, not ammonia or nitrite. Live rock won't finish the cycle: nitrate to nitrogen. Anaerobic bacteria will (at the bottom of the DSB) and release nitrogen gas, as will sponges (the cryptic fuge) and macroalgae will fix nitrates as they grow. This is where all the debate is - fixing or releasing nitrogen (fixing meaning attaching in this sense).

[Pennies2Cents]

You may want to check out the September Newsletter its has some articles about the Nitrogen Cycle... :)

http://www.maast.org/forums/showthread.php?p=699059#post699059