Questions about pavers

[Udest]

I have a piece of pukani I want to make a large over hang out of it has a nice flat bottom but it's very narrow , so I was thinking of using a cinder block paver to anchor it to the bottom so it won't tip.
Problem is is cinder block reef safe?

 

[Doctorgori]

concrete can be cured eventually in saltwater it takes a while and you tube has vids on speeding up curing artificial rock.
I’d soak it in bin but it could take weeks

 

[Udest]

That's what I thought though they should be heavy enough to keep it from moving hopefully without putting pressure on the bottom pane, anyone have any suggestions for that?

 

[Weasel1960]

I am not a chemist nor a seasoned aquarist but would be Leary about commercial concrete products being safe for your fish and corals. I recently had a project at work where we are collecting rain water for plant irrigation. The concrete cistern is adding to the pH levels of the water raising it from 7.6 up to 8.9.

i would suggest getting another flat reef rock/dry rock and use aquarium safe glue/mortar/rods to support your cantilever instead.

 

[Mooses]

I guess technically concrete should be fully cured & inert after a full cure cycle of 28 days; but with all of the additives we are using these days, I don't think I would trust it in my tank. I'm sure they use some nasty quick set additives for pavers especially to aide in the manufacturing facility logistics.

 

[Udest]

That is a big concern of mine since they don't list what's in it I know paul.b uses mortar in a lot of the rock work he dose.
Also on the pH issue is a given with concrete I just don't want to spend a small fortune of reef putty

Anyway I guess in the meantime what I'll do is get a broken pice of paver from the depot and try curing it and see how that goes.

 

[Reverend Turtle]

Travertine tile. It's limestone just like your pukani.

 

[Udest]

The taverntine may work if it's thick enough like the suggestion there I saw some wall tiles that may work.

Now the question is on a binder for all the stones that are going to make this thing up. I have hear some materials either don't hold very well or begin to crumble which is a concern what have you guys used?

 

[Reverend Turtle]

I would use super glue gel myself.
Could always bust the tile up, then glue together to make a pedestal.