UGF as Plenum

pat_man_ta

Premium Member
I set my tank (29g) up with a UGF (Undergravel Filter) and crushed coral substrate. I am having second thoughts about it.

The idea was to run the UGF for about a month to get flow through the substrate and then remove the towers and air so the baseplate acts as a plenum. What do you think of that?

I am not happy with the crushed coral at all. It looks like cat litter and every time I shift something it is STILL releasing massiv amounts of silt. I have 15 lbs of it in there.

This tank is very early in its setup so if i'm gonna make changes, NOW is the time.

I am thinking I will remove at least half of the CC (crushed Coral) then add some LR rubble from Premium Aquatics (which I have in my nanos) and sand. I suspect this would, at a minimum, necessitate addition of screening? (Ref: http://www.idahoreefs.org/ReefCalculator/plenum.asp ).

The tank is currently running on a Fluval MSF 404 with a mere 13lbs of LR to seed the base rock (12 lbs), filter and subsrate. Lighting is currently a clip lamp with a small screw in 50/50 PC (my new Oceanic PC fixture will arrive Friday).
 
*bump*

i really could use some direction on this, i have to move fast and have limited hours at my disposal for the next few weeks :(
 
That is kind of the old school way of doing it.

I think that a Deep Sand Band would probably server you better. Also more live rock. It will take you a little time to get it all up and running, but would be a better bet.
 
ok, so, plan is to remove most of the CC, put a nylon screen over the UGF and add sand.

Rock is a work in progress at the moment. I'm collecting more as I can. I spent a bit too much on the last LFS run.

I'm hesitant to get into DSB's.
I don't know much about them really and I'm not at this point a fan of the look of them. I'm sure I could be swayed to the Deep Side though ;p
 
As said, the plenum method is outdated technology.

I would remove the UGF all together and just get some nice white play sand. A DSB in a small tank doesnt make much sense to me. To be effective you need 6" of sand, some say more, but thats a significant portion of your tank. A inch or so would do just fine, its for looks really. You can get a 40 or 50lb bag for a few dollars. You dont need to buy live sand.

Good luck.
 
15 lbs of crushed coral isnt enough to cover that UGF is it? Sounds like a thin layer to me. If you go to sugar fine sand, a lot of it will eventualy work under the ugf plate unless you screen it.
 
<a href=showthread.php?s=&postid=7856865#post7856865 target=_blank>Originally posted</a> by Catharsis70
15 lbs of crushed coral isnt enough to cover that UGF is it? Sounds like a thin layer to me. If you go to sugar fine sand, a lot of it will eventualy work under the ugf plate unless you screen it.

Actually it's about 2.5" deep.
I am leaning towards coarser sand mixed with rock rubble and a screen.
 
If you want more info on pleniums, do a internet search for Bob Goemans. He has done a lot of work with them.
 
<a href=showthread.php?s=&postid=7858336#post7858336 target=_blank>Originally posted</a> by pat_man_ta
Really, I just want to know what a good idea to do with this tank would be.

Well it's your tank.:) There are many different ways to set up a tank and there is no "right or wrong" way. To each their own.
If you want opinons there are many. It it was my tank (which my first tank was a 29) I would use a 1 inch or less bed of super fine sand, 20 lbs or so of LR, 20 x gph flow (around 600gph) and what ever lights for the type of corals you want. There is no real need for a plenium. Some like them some don't. I do not think it has been proven that they provide any real benefit. The orginal Jaubert method, used a constant change of NSW so that may have something to do with the results he got.

Using crushed coral will tap a lot of detritus and eventally lead to problems.

JMO
 
Yeah, I think i'm going to ditch the bulk of the CC. The idea was to seed it with GARF Grunge but now I don't think that's such a great plan. That and I cannot get past the fact that it looks like CAT LITTER!

Both of my nanos have 1" fine sand beds and other than a raging hair algae bloom in one of them, they are pretty stable ;p

I think I am going to go with my plan of a rock and sand bottom with alot of rubble pieces.

What sand should I use? I have used the fine white sugar sand and the coarser pink sands in my tanks. Has anyone used the Black sand?
 
You can use many different sands, but stay away from silica sand. You could use the silica, but it is used to make the glass- and is hard enough to scratch the glass.


Regular aragonite has always worked well for me.

Do a search for "Southdown" You can buy it at HomeDepot for cheap.
 
The black is a silica sand then eh?
I do remember getting it stuck in my hands when I was helping a friend set up his FOWLR. (his substrate is a mix of black sand, off the shelf live sand, and a smattering of crushed coral about, all @ 3"+ deep)
 
I have run plenum systems for years and the only down side I have found is that they are ugly(kitty litter). So I now try to set them up remotely. Plenums are old technology but they have been proven. There are many plenum systems here in Boise that have been set up for more than 12 years that are still going strong. In 2003, Dr Jaubert had a 17 year old plenum system that had not has a water change in over 5 years...

Using an under gravel plate for a plenum is not a good idea. The UGF plate usually has a large surface area with small slots in it to move the water through. The plate is designed so that the water will be pulled/pushed evenly through the substrate.

A well constructed plenum will be made with a frame that is very open and will not restrict water movement. Many use egg-crate and a non-metal screening.

Just as an UGF plate makes a bad plenum, a properly built plenum makes a bad UGF...

Thanks,

Scott
 
Thanks!

I plan on removing the UGF mess and much of the CC today after work.

I will be kicking myself the whole time for setting it up like that to begin with I'm sure but I suppose I had to try it to find out that I didn't like it and it won't work (well).
 
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