Tanks And Heavy Rocks

[karawr]

How safe is it to lean heavy rocks against the corners of your tank, on the inside? I want to put some larger rocks in the back corners to give a little depth but I'm worried this will put pressure on the walls and result in disaster.

 

[Duz]

I'm thinking about doing the same thing, but with smaller rocks. So will keep an eye on this topic any advice would be good.

 

[StandbySetting]

Generally not a good idea, as it puts stresses on certain points of the tank.

 

[karawr]

Should you just avoid large rocks in general in a tank? Even if it's just on the bottom, as it will just put pressure wherever it is.

 

[StandbySetting]

On the bottom it's fine as the mass of the rock is generally distributed evenly by egg crate which should be positioned under the rock, it's possible to do the same with the sides of the tank but personally I wouldn't like to risk it.

 

[karawr]

Didn't even think of putting anything under it. So use eggcrate if you do put heavy items in your tank?

I don't think I'm gonna risk it either... yikes, scary. Guess I'll just do it with small rocks then.

 

[Duz]

Ok thanks, for the advice.

 

[StandbySetting]

Yeah, use egg crate underneath rocks, it's what is used in marine tanks that have live rock in them.

 

[Bignose]

Rock like gravel or sand under a large rock will also distribute. What you want to avoid is a corner putting high pressure on any area of the glass.

Remember the difference between weight and pressure. The weight of the rock cannot be changed without breaking the rock itself. But, the pressure is the mass per unit area. P = F/A. I.e. the pressure of the Earth's atmosphere is 14 pounds of force per square inch. So, when you have a heavy rock, to keep the pressure (P) lower, you want to increase the surface area (A)the force (F) of the weight will act on.