Help me take the plunge! Deep Sixing My UGF!

[Chris A H]

I've kept fw fish for 12/13 years, SW fish for about 4 months. Bought my tank from one of my wife's friends who was moving. It is a 75 with a UGF, a skimmer, a sump, and 45-50 lbs of live rock. Everything has been going well except I keep getting nitrate spikes. I've finally come to conclude that everything I've heard from reefers, read on the net, or read in books is right and the UGF probably needs to go.

I'm going to pull the UGF out Sunday afternoon. Every FW tank I've run has run great and run for years on a UGF.

I'm really nervous because my fish are doing really well even with the nitrate spikes. I keep feeling in my gut that Lr and a skimmer aren't enough even with all that I've read.

Please tell me to pull out the UGF and be done with it.

THANKS

Chris

 

[myreeef]

Hey Chris,

There are many ways to setup a reef tank. My personal preference is to use a deep sand bed (dsb) in both my main tank and in my sump/refugium, lots of live rock (but not nearly as much as most people quote) and a really good protein skimmer.

Other people prefer a plenum to a deep sand bed, or they will only put the dsb in the refugium. Lots of macro algae in the refugium with some LR and no predators. As far as I know, the under gravel filter in a salt water setup is simply a nitrate factory.

Post more information about your tank setup, and I'm sure lots of people will give you plenty of ideas.

 

[Mouse]

Some people have been known to just seal off the UGF, as a kinda psudo Phlenum, providing the sand on top of the UGF is sufficiently deep to reduce the circulation into the phlenum, it'll at least save you form having to take it out, even if it doesn't work precicely as a plenum should.

 

[Anonymous]

I keep feeling in my gut that Lr and a skimmer aren't enough even with all that I've read.

Well, every reef tank I know of runs without an UGF, so I'm sure it's enough. But what kind of skimmer do you have?

 

[LCGoldman]

If you have a sand bed on top of the UGF, depending upon its depth (the deeper the greater the risk), it might not be a good idea to remove the UGF but to seal it as suggested above.

The sand has trapped a of gasses that would be extremely hazardous to the living organisms in the tank if the sand bed is disturbed which would release the gases.

 

[Anonymous]

You were planning on taking out the critters, right?

 

[keethrax]

If you have a sand bed on top of the UGF, depending upon its depth (the deeper the greater the risk), it might not be a good idea to remove the UGF but to seal it as suggested above.

The sand has trapped a of gasses that would be extremely hazardous to the living organisms in the tank if the sand bed is disturbed which would release the gases.

If the UGF's been running this shouldn't be a problem, I wouldn't think.

At the same time, if you're planning on sticking to fish, the Nitrate spikes may (dependign on the severity) be less ofa probelm thatn the chok and stress that will incur by taking the livestock out to do the change.

Pulling the UGF will potentially cause a fairly hefty cycle depending on how much of the bilogical filtration is going on there, and how much is going on in the live rock already. If most of it is already being done in the LR< there shouldnt' be a probelm, but it a big enough proportion of it is being done in the UGF, you may see ammonia and nitrite spikes as the liverock bacteria population catches up.

Personally, unless the nitrate spikes are pretty high, or unless you plan on adding things other than fish, I'd leave the UGF in place. I wouldn't set up a tank with one, but if it was fish only, I wouldn't take on out of a tank either.

 

[Anonymous]

How hard would it be to change a UGF to a plenum? Seems like most of it is built for you already and would just need a little modification.

 

[Anonymous]

If it was me, I would set up a container and put the rock and water in that. Then catch the fish and add them too. Doesn't seem like it should be that stressful. Then take out the sand and add the water, rock and fish back.

But as was said, if its a FOWLR than maybe it's fine as is.

 

[LCGoldman]

I don't think you could nor should add everything back so quickly... the water will be very "polluted" at that time. You would probably have to perform a large water change.

 

[Anonymous]

That's why I would move the water out to containers first.

 

[LCGoldman]

I missed that part. <blush>

 

[Anonymous]

How hard would it be to change a UGF to a plenum? Seems like most of it is built for you already and would just need a little modification.

I have the same question.

 

[Chris A H]

Thanks for the responses, guys! I really don't want to have a second cycle, so I disconnected one of the power heads on the ugf tonight. It's going to be a FOWLR for sure, but my nitrates went from 15 ppm to 185 ppm in one week. I think that part of the problem is the 3-5 inch bed of CC that is on top of the ugf-even if I stir it up good during a WC, alot of gunk remains.

The livestock will go into my spare 30 Gallon Tank for several hours while I switch all of this around.

As far as a refugium, I've got an in sump skimmer and a 29 sump-as soon as I can get the time I'm going to put an scrylic divider in the sump and add a refugium. A refugium would probably pull me from Say 20 ppm of nitrate down to 5 or 10; it can't pull me from 180 ppm to 10, so I've got to solve my larger problem first.


I would be very interested in reading about a plenum method, if anyone has links. Anything with actual test results, double blind scientific type tests, etc would be great.

The best reef tanks I've seen have been DSB's; however the idea of anerobic places in my tank is really counterintuitive (sp?) and scares me silly.

I'm reading everything I can find on the DSB/SSB debate in the salt water hobby. If I put this thing back I'm going to put about 1 1/2 inches of CC down until I can study some more.

BTW, does anyone here run a canister filter or a Wet/Dry along with live rock? I'm planning on trying just LR and a skimmer. The tank is a 75 with one Banghi Cardinal, two small damsels, and two one inch tomato clowns.

Hopefully if I feed lightly I'll have some room for error with the switchover.

Chris

 

[myreeef]

What grain size is the crushed coral?

If you are trying to get some of the smaller fauna to inhabit your sandbed and become part of your filtration system you may want to get fine sized araganite to add to or replace the crushed coral. But my focus is reef tanks, so that last suggestion may not apply to a FO tank?

I have heard/read many arguments for and against DSBs. I decided to use a DSB because I asked myself these two questions:
How deep is the sand bed under the ocean? and
Is the sand bed under the ocean killing any fish?

In debates at our reef club (plug here for SCMAS), I through out those two questions as my arguments for a DSB. IMO I am trying to mimic nature a little more closely, the opponents retorted with "I can't duplicate nature...". In our club, DSBs and plenums seem to be working well for our members that use either.

I am not a plenum expert, but I don't think that your UGF will work exactly as a plenum should; because burrowing critters will be able to get through the holes in your UGF to occupy/die in the void bellow. You may want to ask around about what negative impacts that may or may not have.

anyhow, that my 6 cents worth :twisted: