# Stupid home made rock wont sink...Help me please



## gmoses (Dec 4, 2008)

i added a rock to it initially and i found it was to light. So i went out and bought a bigger rock (6 lbs) and it still wont sink. Now i can t do much more weight as the rock will be to big and look bad. But i worked hard and think this cave is needed for the bigger fish i plan to have and it just looks cool. Please any thoughts how to get this to stay down would be greatly appreciated. I am all out of ideas. 
Its going in this tank


----------



## knotty dreadlocks (Oct 31, 2008)

gmoses said:


> i added a rock to it initially and i found it was to light. So i went out and bought a bigger rock (6 lbs) and it still wont sink. Now i can t do much more weight as the rock will be to big and look bad. But i worked hard and think this cave is needed for the bigger fish i plan to have and it just looks cool. Please any thoughts how to get this to stay down would be greatly appreciated. I am all out of ideas.
> Its going in this tank


your tank looks good. my suggestion would be to silicone a peice of slate so you would have some type of base on it and you can still cover that peice with substrate


----------



## Mcdaphnia (Dec 16, 2003)

You could also try drilling a small hole in the top of the cave and out and up toward the back to prevent any air building up inside the cave. Acetone Finger nail polish remover) will shrink styrofoam making it less bouyant. Even if the only access to the foam is in one or more small diameter drillings.


----------



## gmoses (Dec 4, 2008)

i actually cut a 2 inch hole in the top hoping to allow the air to pass through but not much help. I would definitely be open to the finger nail polish idea...any idea how that would affect the water in the tank. Or would that just dissipate over time...?


----------



## a_c_arnold (Mar 7, 2008)

Make the hole thing out of concrete. If you have to have that piece, maybe you could attach it to a slate tile and bury the tile beneath the sand and a couple rocks.


----------



## Stickzula (Sep 14, 2007)

I would do the acetone/nail polish remover trick to remove the majority of the styro. Then I would fill the void with sand hope for the best. Nice looking tank by the way. I like the bg. If it were me, I would try to eventually replace the holy rock with more diy modules to make it more congruent.


----------



## tominator (Nov 21, 2008)

Isn't stryofoam flameable? I'd use a lighter first and see if I could get some of it to burn out, unless that is a bad idea for some other reason. That way I'd avoid introducing carcengenic chemicals into my tank.


----------



## TheLaxPlayer (Dec 21, 2003)

The acetone will quickly evaporate, burnt polystyrene will not and it is also a carcinogen.


----------



## Mcdaphnia (Dec 16, 2003)

TheLaxPlayer said:


> The acetone will quickly evaporate, burnt polystyrene will not and it is also a carcinogen.


 Acetone does not chemically change the styrofoam. It just softens the styrene it is made of allowing air bubbles to escape. Then the acetone evaporates. The combustion products from burning styrofoam contains many toxic chemicals.


----------



## deangardiner86 (Dec 9, 2008)

I've just made my own rocks, caves and background etc (will put pics up soon) and i made a few holes in it with a cigarette and then filled them with more concrete to give it more weight, maybe you could drill some holes fill them with concrete and then re-paint?


----------

