Sand first? Rock first?

[ThRoewer]

Always rock first or your aquascape is floating on the sand and prone to collapses. This is especially important if you have any digging fish, shrimp or crabs.
Also rocks on top of sand may create anaerobe (black) zones that can be dangerous to your animals when breached.

If you want to protect the bottom glass, add an acrylic sheet or eggcrate on the bottom.
Sand is only filled in after at a minimum the base rocks are in their final places.

 

[Reef_Mania]

When I set up my tank I used rocks that were cut so they had a flat bottom to rest on the glass. Those were the base rocks and I built up from them. I added the sand after. The rocks are solid and don't shift around even without the help of rods or pvc supports.
You can also put egg crate down the size of the tank to keep the rocks from shifting and then the sand over that.

Is it bad to put egg crate down first? Seems like it would allow detritus to sit inside all those squares?
Just curious.

 

[thegrun]

As the old adage goes "only a fool builds his house on sand", so also goes with placing your rocks on top of sand. Rock first, or you risk a rock slide as the sand shifts out from under your rocks. If you are worried about protecting the bottom of your tank lay down a piece of egg crate which also helps anchor the rocks in place (this is actually egg crate's primary function, to lock in your rocks so they do not shift over time due to the weight of the rocks pressing down and outwards).

 

[ThRoewer]

Is it bad to put egg crate down first? Seems like it would allow detritus to sit inside all those squares?
Just curious.

If that's a concern, just use an acrylic sheet.

 

[davocean]

And now on to the great eggcrate debate...

 

[thegrun]

I'm not sure where the "egg crate collects detritus" myth started, but I can tell you that if you have a decent clean up crew you will not have more detritus in and around the egg crate. I've taken down two tanks that were over 5 years old and the sand in and around the egg crate was just as clean as the sand above it. Get yourself some nassarius snails and forget about it.

 

[davocean]

I guess I should have been more specific, I lay down a half inch or so to help level out the natural deviations that will be on the bottom of rock.
This is not going to cause a slide, and that sand isn't going anywhere, it just helps seat that rock sound and level, then I add sand around that.

 

[davocean]

I'm not sure where the "egg crate collects detritus" myth started, but I can tell you that if you have a decent clean up crew you will not have more detritus in and around the egg crate. I've taken down two tanks that were over 5 years old and the sand in and around the egg crate was just as clean as the sand above it. Get yourself some nassarius snails and forget about it.

I actually agree w/ this and have had very similar experiences, it's just another of those topics people seem to get really weird about.

 

[Reef_Mania]

I was just asking about it since it was stated earlier in the thread... Moved off topic from where it started. The rock first / sand first could go on and on its just a mater of preference i feel.
SWAMPGOAT hope you got some info you needed.

 

[Arkayne Reefer]

Depends on what you want too keep as well. Anything that digs or sifts and rocks go down first. On large tanks I like to put down egg crate, full in the squares with sand, then rock and then add the rest of the sand. For smaller aquariums I prefer a little sand so the rocks aren't directly on the glass, then rocks and then the rest of the sand. But everyone has thier own way. Just read up on everything and do what makes the most sense to you.

 

[Swampgoat]

I have my answer! Well, I almost have the answer.

Everyone provided great information and I really appreciate it. As some of you said, it seems to be partly a personal preference and partly dependent on what life will be in the tank.

Each answer was backed by good logic. It seems to me that the major consideration is rock stability. For that reason, I now plan to make my rocks as stable as possible from the beginning. I have tools and experience and so I may buy one live rock and determine the difficulty of drilling, sawing, chiseling and epoxy-ing it.

After establishing how to fix one rock to another with more than just balancing, I sort of like the idea of a thin layer of sand (to allow some settling) followed by rocks followed by a final, thicker layer of sand.

THANKS TO ALL!