I'm in the process of setting up a reef tank and I was wondering about the rock placement. I've read to put the rocks in and then the sand to avoid "dead" places in the sand and to prevent shifting. Since I plan on having a 4" sand bed, I'm wondering if I can put the rocks on top of the sand. I hate to pay for a rock that's going to be buried in the sand where you can't see it. So...any advice on whether or not it's ok to put the rocks on top of the sand is appreciated!

There's no such thing as "shouldn't" in reefing...well maybe a few like, "shouldn't dump motor oil in tank", "shouldn't forget to pay the electric bill so they don't cut off power", just to name a couple [img]/ubb/lol.gif[/img] ...but you can do what you want to do with your rocks. However...would it be wise?...depending on what type of critters you will have in your tank...if they burrow or dig, like my orangetail blue damsel and strawberry dottyback...those rocks are gonna shift!

The rock lost won't necessarily be too much...but worth the few inches lost IMO in order to save you from a rockslide...[img]/ubb/biggrin.gif[/img]
If you really can't see yourself burying the rocks, then prop it up with some rubbermaid containers, cut PVC pipes, etc...then place the rocks before the sand...will give your rocks a secure base.

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The NUT!
Alex's Ocean Realm
GO FOR A DIVE!!!
http://home.earthlink.net/~amariquit/thereef

OK, here are the possibilities as I see them:

1. Place the live rock directly on the bottom of the tank and then add sand.

2. Place cheap base rock directly on the bottom of the tank and then add sand.

3. Get yourself a 10' length of 3" or 4" PVC pipe, cut it up into 4" lengths, drill several holes in each piece, place PVC sections on the bottom of the tank (cut side down) and then arrange the live rock on top of the PVC being sure that each piece of rock rests on three or more sections of PVC for stability. Then add sand. (Put sand in PVC, also.)

4. Get yourself some 3/8" acrylic rod, then drill some holes in the bottom of the live rock, insert cut pieces of acrylic rod into holes (epoxy if necessary) and then set the rock on the bottom of the tank sorta like little miniature offshore oil rigs. Then add sand.

Options 3 & 4 will save money and reduce weight. If you place your rock on top of a 4" sandbed you could have problems down the road with stability...especially if you get any sand stirrers (but even clowns dig holes).

HTH [img]/ubb/smile.gif[/img]

Ninong

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Irrational Exuberance

[This message has been edited by Ninong (edited 07-01-2000).]

Thanks for the suggestions! I guess that's one of those "doh" things...I never really thought of using pvc or something else cheap in the bottom. I guess I have just been wary about putting anything "artificial" in there, but plastic makes sense. Ok, another little questions, since you all have had such good suggestions thus far [img]/ubb/smile.gif[/img] What is a good way to stack the rock so that it doesn't collapse? Do you glue it, drill it, stack it or what?

Thanks!

Mine ar just stacked and so far have been fortunate and my stars and crabs have been behaving...but as they get bigger is another story...actually it's the snails that knock little rocks everywhere in my tank [img]/ubb/smile.gif[/img]

But I have read that others drill holes and insert rods or plastic screws...Epoxy IMO will only cradle the rocks unless you get it deep into the crevices...then there's platic ties, cords, rubberbands...even sponge growth...your imagination is the only limitation...[img]/ubb/biggrin.gif[/img]

Good Luck!

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The NUT!
Alex's Ocean Realm
GO FOR A DIVE!!!
http://home.earthlink.net/~amariquit/thereef

Like Nut says, most people just stack it. If you have nice shapes and large enough sizes, you can usually get it to interlock without having to use plastic ties, etc.

If you were doing a large tank, say 500g, then you might want to consider a support framework to give the structure more stability (you don't want to end up like the Texas Aggies bonfire).

Even in a small tank, if you wanted to set up a nice large cave with overhang, for instance, you could rig up a simple unobtrusive framework to support the over hanging rock using small PVC or acrylic rods...as long as you kept it simple and concealed from view. [img]/ubb/smile.gif[/img]

Ninong



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Irrational Exuberance

i agree, my tank has been up for two years and never have i had any rock problems, stacking is the way to go.


Jade

To set up a very effective nitrate reduction bed as i have done and been very successful with is as follows. Read read read =) books books Anyway here it goes fill bottom of aquarium with rock pieced etc to stabilize big rocks. spread rock pieces out on bottom so there is gaps then you lay down sand layer. or multiple layers if using fine sand on top. this will simulate plenum if you do not want that. and the small pieces keep the big ones stable as well as providing air space under for denitrification. this is what lee eng did and fascinated people years ago.