should i use eggcrate?

Just do the math. Measure the inside of the tank and you can then figure out how much eggcrate you'll need.
 
I have a wall of rocks in the back of my 180 gallon tank from the bottom to the top and it looks like a reef. Some of those rocks that came from the gulf are very heavy. I used egg crate on the entire bottom of my tank to help distribute the weight more evenly across the bottom of the tank with fewer stress points on the glass. It has been functional for over 15 years and worked for me extremely well.

Hope this helps,

John
 
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