Eggcrate for rock
 

So I ask, reading Brad saying that was a stupid thing he did.

Why is that?

Cant it be cut where the sand may expose it?

Does it not support the rock better and keep it from sliding?

If its stays covered in sand, whats the difference?

Enquiring minds wish to know. I have never done it but have it in my tank now. Of course nothing else is on there so no biggy.

Tanks..:smile:

Doug, really, unless you're tipping the tank, rocks aren't going to slide. Gravity keeps them on place pretty good :)
I would say, in fact, that if you cut the egg crate to just fit the rock, it would have a better chance of sliding (when you tip the tank, of course) :)

Oh, and this. If is a big IF!!

But it looks important, sitting there on the glass.

Trust me, it's not :)

Ok. I will just have to build some interesting structures with good support. I have 5 bags of FijiCrete on the way.

Not sure if I agree I mean talking about my old setup 180glns display I had egg-crate running where my rock was going to be and I silicone it to the bottom pane then sand then the rock pressed to hit the eggcrate.
Not sure if it did anything but in my mind my rock work was sturdy but still few tumbles only my fault.Although my new setup with using Fijicrete I am sure not going to use any egg-crate and all rocks will be glued in place.

Eggcrate under sand & rock sounds to me like a recipe for a nitrate build up.

I have used egg crate under my rock without any problems for years but I am about to set up my 180 and am interested what the alternative is. I have a pistol shrimp and convict blenny, these two guys can completely undermine a large rock in one night.

The alternative is not using it. Simply arrange the rock on the glass, add sand around it and nothing can dig underneath.

I have worried about pressure points or small areas of the rock putting all the weight in one small area on the glass.

Not something to worry about unless the rock is the size of a small car. Any rock you use will have either a fairly large single spot or multiple points of contact.
As an example of the strength of glass, I tried to remove a center brace once with a hammer. It was unbelievable how hard I had to smack it to get it to break. Unless you're throwing rocks into the tank, you have nothing to worry about :)

Interesting, maybe I will go that route on my new one, thanks!

Eggcrate on bottom?
 

Yeah, I had to consider that a couple years back when I was rearranging the rock and sand in my tank. Listened to the various opinions, but never made any sense to me use the eggcrate. So I just went with rock on bare bottom and a very light sand bed. Worked out well.

I dont get that one Greg?

I suppose, technically, it could restrict water movement, although I haven't found this to be the case with 2" of sand or less. My NO3 has always been 0.

I heard some guys mention fijicrete, is that a cement??

http://www.canreef.com/vbulletin/sho...d.php?t=103405

If under the sand I dont see how. Exposed, yes I agree.


Perhaps I will just stick with bare bottom. Always worked well for me so far. No eggcrate....no sand.

Still going to use to much rock compared to you guys....:lol:

At your age, we expect you to be stuck in your ways :)

:mrgreen: