How to Protect Glass At Bottom of Tank?

[couvier]

gas pockets eh? didn't think of that. maybe drill a small hold every inch or so to let the gas out?

 

[dougall]

To each his/her own. But I would have expected it to take off more if there wasn't a bigger problem.

 

[the loach]

Unless you are putting lots of (big) rocks in there it's not going to do anything to protect the bottom of the tank. Did you know a tank bottom can crack by just 1 grain of sand underneath it? Put tanks, especially the big ones, on styrofoam or some other soft layer. When you wrote "My stand has gotten a LOT better since I lost two aquariums, it is now perfectly flat and sturdy " it says to me it was all in the stand... any 180 gal stand needs to be perfectly flat and sturdy. They don't crack by vacuuming...

 

[dudley]

The use of egg crate or drop ceiling light grids was really popular a number of years ago as a support for large rocks in aquariums but has really fallen out of favor as there is no real proof it helps spread the load of rock piles.

I did use small sections when I set up my 72" L x 24" W x 30" H glass tank with no tempered glass panels as support under large piles of large rocks. I did find that the grid can accumulate dirt and debris over time especially when you have cichlids that like to move the substrate around. Live plant roots can also grow through the grid and make removing them much more difficult. I have since removed all the egg crate from this tank and just have the rocks piled up directly on the glass bottom of the tank.

If you are worried about dropping rocks into the tank when you set it up, either fill the tank partially with water or use towels or styrofoam temporarily to protect the glass bottom in case you drop any rocks in a dry tank. Always add any substrate to the tank AFTER you've added any rocks larger than your fist to avoid the possibility of accidentally toppling over any rock piles.

I would not use the opaque light panels for the reasons given by D dougall plus the panels do not drill well at all and usually crack.

C couvier , you mentioned you use gravel as your substrate, any chance you can post a pic or two of what type and size gravel you are using? I highly doubt that the usual aquarium gravel and vacuuming it will cause tank breakage.