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View Full Version : Using PVC to elevate rock above DSB?


mtbe
01/27/2006, 04:32 PM
My 38-gallon reef tank has been set up and running fairly well for a few years now. It houses a brain, an anenome, some polyps, a few fish. Nothing fancy.

The only complaint i have is the accumulation of detritus at the base of the live rock, where it touches the DSB. This allows the growth of a little hair algae in these areas. There's no other problem algae in the tank.

What i was thinking of doing was using 4 or 5 pieces of 4-inch diameter PVC, stood vertically, to make piers to support the rock work a few inches above the sand. At my job we have slotted PVC screen that i could swipe. This pipe has 0.020-inch slots milled through the pipe every 1/4 of an inch.

My questions are:
Should i fill the inside of the screen with live sand?

Will the typical sand critters be able to move through a 0.020" gap?

Should i notch out a larger hole in the screen below the surface of the DSB to allow larger critters (such as narssissis snails) to move in and out of the pipe?

Any good reasons to not do this? I'd really like to be able to eliminate these dead spots.

Thanks,

xtrstangx
01/27/2006, 04:35 PM
Yep, you can use PVC to elevate your rocks.

As far as the holes in the PVC.. you could make the ones below the sand bed bigger (a Dremel would work well) or you could leave it as is, IMO.

You may also think about using eggcrate on top of 3-4 piers of PVC. This will provide a really stable base as well.

impur
01/27/2006, 05:40 PM
I used PVC racks to lift my rock off the sand. I wanted to have flow under the rocks to stop detrius/food/etc from settling under them.

I basically built a structure like so:
http://img.photobucket.com/albums/v292/impur/P2070024.jpg

On the right side rack, i used 4 pieces of PVC about 3" long that act as legs to raise it up above the sand.

Here is how it looks now. The PVC gets covered in coraline pretty quickly

http://img.photobucket.com/albums/v292/impur/P1090148.jpg

http://img.photobucket.com/albums/v292/impur/P1090149.jpg

AllenFord_SC
01/27/2006, 06:10 PM
If you fill the PVC with sand you will want to drill holes below the surface of the sand to let critters get inside and keep it stirred up. Take a 3/16 drill bit and drill dozens of holes around the pipe.

Alaskan Reefer
01/27/2006, 06:24 PM
I have a rack that looks very similar to impurs, albeit it higher (two tiers) and larger. I recommend closing off the lower ends with caps (just like impurs) and leaving just one or two ends open to take on water (so it doesn't float which makes installation pretty difficult). If you really want to get crazy, plumb a powerhead into your rack and drill holes in it low and parallel to the sand surface, you'll never have collection under the rocks again...

mtbe
01/27/2006, 08:54 PM
Cool. I'll proceed this weekend.

My main concern was not to move my 'dead' flow space from around the rock to inside the slotted 4-inch pipe. but no one seems to be concerened with that. So that's reasuring.

thanks.

bllfish
01/27/2006, 09:43 PM
I drilled holes into my large base rocks and used solid clear acrylic rod to elevate it.

javajaws
01/28/2006, 08:27 AM
<a href=showthread.php?s=&postid=6606577#post6606577 target=_blank>Originally posted</a> by bllfish
I drilled holes into my large base rocks and used solid clear acrylic rod to elevate it.

That's exactly what I did as well. Used 1/2" acrylic rod. Those rocks drill like butter with a masonry bit.