Purpose of Eggcrate Under Rock?

[Tradewinds]

I've looked through a number of the builds here and have noticed that some folks will put a sand bed down and then rock on top of the sand. Others have bare bottom tanks with eggcrate, with the rocks on top of the eggcrate (Which I assume is to protect the glass.)

My question stems from seeing tanks that use eggcrate, then sand covers the eggcrate and rocks on top of the sand. What purpose does the eggcrate provide when used in this manner?

[hvacman250]

Still protecting the glass. The rocks should be resting on the bottom in case sifters/diggers dig under the rocks and collapse them. Egg crates distributes the weight of the rock and eliminates point loads.

[jroovers]

For a SSB with eggcrate, which I'm assuming you are talking about, the egg crate assists in keeping the sand uniform over the bottom. Without it, your more likely to get bare spots from sand moving with the flow. That said, I put egg crate under my two rock pillars to prevent sand movmenet and to provide a base of the pillars, but I'm wondering if it nothing more than a detrius trap. I'm considering removing it and living with some bare spots.

[Frogmanx82]

It serves no purpose. Sand offers enough protection from rock falling.

[muttley000]

+1 on the point load statement, that is exactly why I used it.

[Top Water]

I can see how it can help point load. I never used in cause I just used sand and common sense for rock placement. I have a lot of rock w/ no issues. A rock fall would be more a problem to me.

[Sk8r]

I use it. So does my lfs guy, who's been at this a long time. Prevents rockslides, to some extent: mostly point load.

If you use nassarius or conches, no problem with gunk below-sand.

[iwishtofish]

Originally Posted by Sk8r

I use it. So does my lfs guy, who's been at this a long time. Prevents rockslides, to some extent: mostly point load.

If you use nassarius or conches, no problem with gunk below-sand.

Sk8r, the egg crate doesn't prevent those critters from moving laterally beneath a SSB?

[Sk8r]

Nassarius and conchs have a little 'trunk' that they extend into places, and they go through the sand layer at any level they like. I think they must view those little squares as just that many little bento boxes: they can certainly dip into them with no trouble.

When I broke my setup down for a move, the undersand was clean as you could wish. I answer a lot of questions about problem sandbeds, and I think most of them could be cured by true nassarius and conches. Nice thing about nassarius---they rarely surface unless really hungry or unless there's carrion to be had: so they're not available for fish to pick on. Even in a fish-only tank that won't allow regular snails, these guys can probably operate.

[iwishtofish]

Originally Posted by Sk8r

Nassarius and conchs have a little 'trunk' that they extend into places, and they go through the sand layer at any level they like. I think they must view those little squares as just that many little bento boxes: they can certainly dip into them with no trouble.

When I broke my setup down for a move, the undersand was clean as you could wish. I answer a lot of questions about problem sandbeds, and I think most of them could be cured by true nassarius and conches. Nice thing about nassarius---they rarely surface unless really hungry or unless there's carrion to be had: so they're not available for fish to pick on. Even in a fish-only tank that won't allow regular snails, these guys can probably operate.

Good info - thank you!

[Tradewinds]

Originally Posted by hvacman250

Still protecting the glass. The rocks should be resting on the bottom in case sifters/diggers dig under the rocks and collapse them. Egg crates distributes the weight of the rock and eliminates point loads.

That makes sense. Thanks for the feedback everyone!

[Frogmanx82]

I just think they are unnecessary. A tank with a sand layer will protect the glass from falling rock. I'd rather have the sand not be blocked by the crate and it looks bad if it gets exposed. It's pretty tough to break aquarium glass. If it makes you feel better I suppose there's nothing wrong with it. If you had a particular rock that was heavy with an odd point you could just use a small piece of egg crate just under that rock. It's certainly not required.

[JMartin104]

Originally Posted by Frogmanx82

I just think they are unnecessary. A tank with a sand layer will protect the glass from falling rock.

Unless you have livestock that shifts the sand. My daughter's tank has a few areas where her Damsel "moves" the sand to the point where BB is exposed.

[Frogmanx82]

So you would like to see eggcrate instead of bare bottom?

[JMartin104]

Originally Posted by Frogmanx82

So you would like to see eggcrate instead of bare bottom?

Less obvious than the dark bottom.

[smoyer]

its for protecting the glass. i have a bare bottom tank and don't use it. i would think it could trap nutrients.

[Frogmanx82]

Originally Posted by JMartin104

Less obvious than the dark bottom.

I would disagree, I'd much rather have glass than egg crate to look at. To each their own on that one.

[JMartin104]

Frogman, I think you really can't go wrong either way - it's a personal choice. I put it on the bottom of my 110 but not my daughter's 29. I don't think there's any real proof one way or the other of which is better. I think this might be one of those "6 is better than a 1/2 dozen arguments".

[nemosworld]

Only time i did it was when i had an engineer goby and a deep sand bed. but i used pvc instead to hold up the rocks. now that i have a SSB, i don't have anything under my rocks. makes no sense.just put down your base rock, add sand and then scape from there. or add your scaping and sand after. heclk with a ssb it really doesn't matter if the sand went in first or last. by shallow, i mean less than an inch.

[inktomi]

Another reason to use eggcrate, even under sand, is because rock won't slide around when you stack it on eggcrate like it will on sand.

My tank's one of those eggcrate - rock - sand filled in around ones. There's a lot of rock under my sand =\