Rock supports

[Kowkilla]

I'm probably using someone elses idea, but to support my rock of the substrate I took a piece of 2" pvc and drilled alot of 1/4" holes down the length of it all then I cut it into 4" pieces and pushed them down in the sandbed facing upwards and I rested my rock on them.
The reason I drilled all the holes was that I wanted the creatures to be able to move throughout the entire bed even through the pvc

 

[Tinker]

I think it's a great idea. I have about 9' of 4" pvc. I needed a foot and it only comes in 10' legnths. I can cut it into 4" pieces and use them to keep the rock off the sand.

 

[Jrsydevi1]

I like the idea of the holes... never thought about that one before).. :wink:

 

[Anonymous]

What does all of this PVC gain you? Why not just set it on the sand? According to R. Shimek it doesn't help you DSB, in fact the PVC even with holes will reduce or eliminate animal movement in the area.

 

[cboyfan2020]

why don't you just put your rock on the bottom glass and the sand around it. Then you wouldn't have to worry about it? :lol:

 

[amonhen]

I used four inch lengths of 3/4" PVC, kind of like pilings. I drilled three 1/4" holes all the way through each piece (6 holes total). My reasoning for the holes was the same--to allow some movement of animals, nutrients, etc. I use three PVC pilings per rock to give three points of support. Frankly, I think using large diameters probably gives better stability--didn't think of it--but I would guess (pure speculation) my method makes for a healthier sandbed, and also allows for more open sand under the rock, if the shape allows for a cave structure or something.

There are several advantages to using PVC supports. The sand under your rock can settle/shift/get dug out, making your rock structure unstable. I think it allows for more interesting structures, both from a stability standpoint and because there doesn't need to be as much rock/sand interface. In other words, it lifts the rock higher off the sand, leaving more sand surface. Instead of having your rock sinking however many inches into your sandbed, just about all your rock is visible, so you end up with more visible rock per pound. If it's gonna be invisible in the sand, I'd rather pay 40 cents for 12" of PVC than $4 per pound for live rock. Among the disavantages are, as you mentioned, probable reductions in animal and water movement.

While Dr. Shimek is almost certainly right about animal movement being restricted, IIRC he made a home for his carpet anemone by sinking a piece of large diameter PVC in his sandbed. I have the highest respect for Dr. Shimek, and I want to be clear that I do not think this is hypocritical on his part, nor am I intending to attack him in any way. In my view (my words, not his), he did the same thing we did; he weighed the advantages and disadvantages of a certain methods, and went with a way he thought would accomplish what he wanted to accomplish.

--Jeff

--Jeff

 

[M.E.Milz]

You can eliminate the issue of restricting animal/critter movement if you use plastic light diffuser (eggcrate) to build the base for your rockwork. If you do a search in the DIY section, you should be able to find detailed info on the set-up.

 

[Anonymous]

Just add re-bar and pour it full. Not a god damn thing will move through it, but the "ROCK" will loook cooool!

 

[amonhen]

You can eliminate the issue of restricting animal/critter movement if you use plastic light diffuser (eggcrate) to build the base for your rockwork. If you do a search in the DIY section, you should be able to find detailed info on the set-up.

I don't have much experience with eggcrate, but it seems to me that it wouldn't be strong enough to support a couple layers of rock. It does sidestep the movement issue, though. Has anyone done this?

--Jeff

 

[M.E.Milz]

The eggcrate is plenty strong if you form 3-dimensional structures with the use of cable ties. However, my approach has been to bury an eggcrate shelf just below the surface of my DSB upon which the live rock is supported. The shelf is elevated off of the bottom of the tank by intersecting strips of eggcrate placed on end. The shelf:

1) keeps the live rock from sinking all the way into the sandbed,

2) helps to prevent the rock from sliding,

3) keeps fish from digging up the sandbed,

4) but does not prevent critters from moving through the sandbed.

However, I don't extend the the eggcrate above the DSB to support the rock. I prefer to use long pieces of tonga branch rock (if you can find it) for this purpose.

 

[Poor Man]

I cut a 10 foot piece of 2" PVC into 6 inch lengths to support the rock in my 90.

Why not place the rock directly on the bottom? I wanted more sand in my sand bed.

Aside from the sand shifting and destabilizing the rock, I simply wanted to eliminate compaction. If you've ever driven across a yard and had the grass die in your tire tracks you've witnessed the effects of compaction on grass roots.

Never thought about drilling the sides of the pipe, but it seems like a decent idea. I was always a bit worried about trapping pockets inside the pipe. When I tore the 90 down after 18 months the stomatella were in the sand almost to the bottom, and numbered in the hundreds if not thousands.

Next time I may go with solid acrylic rod in a smaller diameter or something along those lines.