Too Many Rocks?

I picked up these big lava rocks for my 29 gallon aquarium. My girlfriend has me worried now if I put too many the aquarium might break. Is this really an issue? Also I suppose I have to worry about falling rocks. Anything I can do to secure them to each other that would be fish safe? I would like to give the fish some hiding spots and also create some height in the tank. I will have a lot of other questions on the forum but lets start here.

 

Also what about rocks against the glass? Is it a bad idea?

 

It should be fine. Lava rock isn’t a heavy rock like other rocks used to aquascape. You should try to have them sit up on each other or support each other. If you want something permanent use 100% silicone. Or you can use aquarium safe epoxy or aquarium safe super glue gel.

Yeah it might be a bad idea if it’s against the glass.

 

I had a tank full of rocks that I took for the beach. I mean it was FULL of rocks and I never had any issues. And these were much heavier than lava rock, and they were against the glass in the back of the tank.

 

If you are concerned about the weight stressing the bottom you could add egg crate (light diffuser) under the rocks.
If they’re is a chance of a rock falling I would silicone it in place, or reinforce the area some other way, falling rocks can cause damage to glass/inhabitants.

Rocks against glass... not “harmful” per se, but a bad idea overall. When you need to clean the glass you will need to move the rock... if it is secured in place by silicone not a huge deal, but realize you won’t be able to get behind it to clean.