If stacking rocks, do you silicone them together?

[jbrady33]

have some slate-type rocks, was going to stack some of them. Do you silicone yours together to make a structure, or leave them as a stack?

[smelly]

I will be siliconing mine.

[seandelevan]

What if you want to rearrange these rocks in the future?

[PlantedRich]

I rarely stack the rocks as they will not look natural. I do a pile which gives many more sizes and shape of hiding spots. Either way, I would not want to attach them so that I could not move them to clean under them now and then.

[WallaceGrover]

I've usually seen silicone or epoxy suggested so it makes the structure more stable...

[Matthew_Machine]

The aesthetics of stacking aside, i'd recommend putting just a bit on there. The last thing i'd want for my tank is a stack tipping over and cracking my tank, or putting livestock at risk. IME, you can easily peel things apart with just a lil bit of silicone.

[jcgd]

If you stack it well from the bottom glass you'll be fine. If you can rock it, or move it around you haven't stacked them well enough.

No silicone, stacked off the glass. About 150 pounds or so of slate:

[Diana]

Silicone peeled off the one time I did that, so I stack it the way it will hold itself up. The more casual, almost random pile looks good.
If I want a more formal effect, like a retaining wall I use expanding foam filler. Not so much to glue the rocks together but to fill between so the substrate stays on the uphill side.

[Complexity]

Silicone is a poor choice if the goal is to attach rocks to each other. Silicone simply peels right off of rocks.

I agree most with the advise to stack the rocks so they are solid and so not wobble.

However, if you feel a need to attach rocks together, waterfall foam works very well. It will grab onto the rock and hold it strong; plus, it's meant to be used in water with fish so it's very safe. I've used it to "glue" on a rock as a base to another rock to add height when a rock was the perfect color, shape, and size, but too short for my needs. Attaching a flat rock to it as a base lifted the rock to the perfect height. Years after being in the tank, the rocks are still attached.

This is the kind of stuff I'm talking about: http://www.amazon.com/s/ref=nb_sb_no...waterfall+foam

[flight50]

I have done aquarium silicone before. I did not have any problems. I did not want any piece to shift once placed in the tank due to tank maintenance or from aggressive fish activity. I also have fairly smaller pieces that wouldn't work well stacked.

Originally Posted by Diana

Silicone peeled off the one time I did that, so I stack it the way it will hold itself up. The more casual, almost random pile looks good.
If I want a more formal effect, like a retaining wall I use expanding foam filler. Not so much to glue the rocks together but to fill between so the substrate stays on the uphill side.

The expanding foam you mention, is this like the Great Stuff brand that you can buy at like Home Depot? If so I might have to try that one day. Wouldn't have thought it was aquarium safe. I plan to setup multiple tanks with 2-3 different substrate levels and I can hold back alot with foam.