Using PVC under rocks

JCox · 11-10-2005, 03:18 PM

I'm moving my 10 into a 20 and have a question concerning using PVC to support the rocks. I have read that it's good to not have the rock touching the sand for waste reasons, but I can't see how that can be aesthetically pleasing with PVC showing between the sand and rock. I'm thinking of doing this more for the fact that my pistol shrimp digs feverously under the rocks and I'm afraid of the rocks shifting and possibly crushing him and the goby. So I'm thinking of having the PVC hidden under about 1 inch of sand or so, that should keep the PVC from being uncovered with any slight sifting of sand from currents and such and also not allow the rock to touch bottom in the event of a cave in. The question I have is, who actually has their rock suspended off of the sand with PVC? How does it look? Again, I can't picture this being attractive in any way.

reef_noob · 11-10-2005, 03:21 PM

Well, it's more attractive than the massive forest of hair algae I had before...

wanareef · 11-10-2005, 03:27 PM

When I had a Sandbed, I used a "PVC rack" under the LR and it did not show at all. The "rack" went down first and the rock on top, then the sand went in. In time the pvc got covered with coraline anyway and you could not tell from the front.

Some guys use a pvc rack with spray bars attached - dual mode.

This is from Steve Weast's site http://www.oregonreef.com/images/photos/p_039_s.jpg this is the racks and this is what it looks like http://www.oregonreef.com/images/photos/p_005_s.jpg http://www.oregonreef.com/images/photos/p_006_s.jpg - http://www.oregonreef.com/sub_aquascaping.htm

hth

dodge41 · 11-10-2005, 03:30 PM

Best thing to do is cut the pvc in section the same depth as your sand bed and drill a few small holes in the side of the pvc. You dont want you rocks setting above your sandbed thats not the point. Its just to raise the rocks off the glass or sand they were sitting on. One for the safety reason and the other so you wont get deposites of waste where nothing can get to it.

JCox · 11-10-2005, 03:37 PM

Wow, Steve Weast's tank is incredible. That looks better than some public aquariums I've seen.

dodge41, why would I need to drill holes in the PVC? I do remember hearing/reading something about that before but I can't figure out why that would be needed?

dobejazz · 11-10-2005, 03:43 PM

Jeff did you see this thread?
http://www.thereeftank.com/forums/sh...ad.php?t=60774

Geoff · 11-10-2005, 04:18 PM

Quote:

Originally Posted by dobejazz

Jeff did you see this thread?
http://www.thereeftank.com/forums/sh...ad.php?t=60774

here is how we came up with the idea.

G~

dodge41 · 11-11-2005, 12:42 AM

Quote:

Originally Posted by JCox

Wow, Steve Weast's tank is incredible. That looks better than some public aquariums I've seen.

dodge41, why would I need to drill holes in the PVC? I do remember hearing/reading something about that before but I can't figure out why that would be needed?

If you dont drill holes in the pvc it can cause the area inside the pcv to become a dead spot, which is what your trying to avoid in the first place by placing the rocks on top of the sand. Drilling holes allows for some water movement and for anything traped in the pvc to be broken down. You could avoid the whole mess by going bare bottom, which is what im going to do when I get my tank for the 2nd time tommorow. Its almost a funny story which I will have to tell later.

JCox · 11-11-2005, 10:29 AM

I still don't fully understand the need for drilling. Well, I understand what you're saying, but how would anything get into the PVC? I'm thinking of a simple rack type structure that will be totally sealed, so I can't imagine sand getting in. Is there a need to drill if it's fully sealed??

dodge41 · 11-11-2005, 12:41 PM

Quote:

Originally Posted by JCox

I still don't fully understand the need for drilling. Well, I understand what you're saying, but how would anything get into the PVC? I'm thinking of a simple rack type structure that will be totally sealed, so I can't imagine sand getting in. Is there a need to drill if it's fully sealed??

Lets say you cut several pieces of pvc into lengths equal to the depth of your sand bed, maybe 3 inches or so? You can place the pvc down first, then the sand or vice versa. I did it the latter of the 2 for my 55 gallon that i had up for about 3 years. So now you have a sandbed with pvc in it and its all level and looks nice. Now you place your rock on top of it. The rock setting on top of the pvc does not seal perfectly to the pvc so there are gaps. As time moves on detritis settling to the bottom and into the sandbed works its way into those crevises. Now those holes you drilled into the side of the pvc helps to add more water flow and allow creatures in your sandbed to get to the waste inside the pvc. This is how I read and understood it to work. Hope this helps as I fully understand how annoying it is when you dont understand something about the reef tank. We have all been there before!

JCox · 11-11-2005, 03:13 PM

OK, gotcha. We were envisioning 2 different things. I actually built a rack out of PVC with 90 degree elbows and t fittings. So the rack I have made is completely sealed, make sense?

impur · 11-11-2005, 03:38 PM

The rack is a great way to keep the rocks off the sand. If you have sufficient flow, you can keep from having stuff accumulate under them which is definately a benefit. Yours looks good! Heres a few pics of how i did mine:

Can't even tell its there now that the coraline has taken over. I need to shorten the ones on the right side.

dodge41 · 11-11-2005, 08:16 PM

Quote:

Originally Posted by JCox

OK, gotcha. We were envisioning 2 different things. I actually built a rack out of PVC with 90 degree elbows and t fittings. So the rack I have made is completely sealed, make sense?

Yes I can see now why you didnt understand what I was talking about. Someone on here built a rack for a bare bottom tank that actually pumped water through it and kept the detritis suspended off the bottom. Great for bare bottom not for sand. Glad we got it cleared up now!

wharyat · 11-11-2005, 08:46 PM

Just sharing a photo of mine.

I just cut pices of 1" pipe to the depth of my sand and placed the LR on top.

tdwyatt · 11-12-2005, 06:41 PM

What the rock looks like when stacked appropriately on top of the pylons, not one piece of rock moved so you can see how high the rock is off the substrate: