PVC Board or HDPE for protecting glass bottom from rock?

[mike550]

Sorry for yet another question about protecting the bottom glass from rock in tanks. I have a few pieces of rock with “pointy” spots where I’d like to protect the glass. I’m thinking either HDPE (same material as “Starboard” and most kitchen cutting boards) or PVC board that I can buy at Home Depot. Any pros / cons of using one material via the other?

Thanks in advance!

 

[Timfish]

I don't see a problem. You will get anaeobic areas underneath them but I don't see how it can be disturbed unless the rock is moved. Persoanlly I like eggcrate.

 

[mike550]

I don't see a problem. You will get anaeobic areas underneath them but I don't see how it can be disturbed unless the rock is moved. Persoanlly I like eggcrate.

Thanks for your reply much appreciated. I still might go with eggcrate but it would need to stay on the bottom of the tank on its own (not float up) because I can’t secure it to the rock. Also thinking of weighing down the eggcrate by gluing small rock or mortar.

My only experience with egg crate is flimsy plastic material. Do you think the stuff from a place like BRS or maybe the egg crate they sell for lighting at places like Home Depot will work?

 

[Timfish]

I use the stuff from HD or Lowes. I break peices so they're only slightly larger than the foot print oof the rock. I just sit my initial rock on it to hold it in place and it can be scooted around some to get it in the right spot if needed.

 

[thatmanMIKEson]

I use abs its cheaper and easily ordered cut to size and thickness. Then I aquarium silicone it to the bottom glass.

Here are 3 examples, its hard to tell on the grown in one's but it's the same application.