Stacking up heavy rocks

[nLinked]

I have a tank that's 2.5 feet tall and want to stack up some of these rocks:

They are heavy and I'm wondering how other people do it. Last time I did it the bottom of the tank cracked. Now I have a bigger tanks with thick edges. I'm weary of stacking them. I have cichlids.

 

[hansoi_888]

try to put egg crate under or that white thing used in lights, i 4got the name LOL sori!! to equally divide the load on all parts of the tank then gravel or sand then those rocks, maybe it will work, those rocks are huge, i thnk that can give to much stress to the tank, plus the water and sand.

 

[wataugachicken]

egg crate is what those grid-type lighting covers are called. egg crate first, then rocks, then sand or other substrate. it diffuses the weight of the rocks over a larger area and protects from single-point contact and rock slides. i have also seen people recommend a sheet of styrofoam, but it does not allow for water movement underneath it and could cause a buildup of waste and toxins.

 

[Wolf3101]

you put the styrofoam UNDER the tank to prevent the weight from causing high spots that could crack the bottom glass... The lightdifuser...(eggcrate) is used to keep the sharp points of the rock away from the glass serface. This works fairly well for light to medium loads but your talking about exceeding that by quite a bit. The best bet would be to have a couple of pieces of thick marble floor tile laid over the eggcrate..a thin layer of substraite...and then the rock.

 

[hansoi_888]

if better not, just try to have light or not so heavy rocks in ur tank.. u dnt wna create leaks in ur tank coz of them heavy rocks, ryt?

 

[Wolf3101]

Nothing wrong with styrofoam and plaster rock work...I've used a lot of it before on ponds. Besides bieng a LOT lighter you can make exactly what you want...

 

[big train]

I would use different rocks those look like quartz some of the heavyest possable rock i would go with the bricks and terracotta planter pot look with a few peices of thin slate bridged over the brick and rock i think your decorations are just to heavy i would find somthing else so u would not have to worry about hearing that big crash and splash in the middle of the night.

 

[joey02]

what about puttin a piece of styrofoam that is cut to the dimensions of the tank....put it inside the tank and the rocks would weigh it down. i think the would be best to stop the rocks from cracking the bottom.