What to put under sandbed?

[marsh1n]

I set up my 675 acrylic tank a few months ago. I have a stingray who really loves to push the sand bed around and leave multiple bald spots. I know I should have painted the bottom of the tank, but I didn't.

Has anyone put something under their sand to hide the bottom of the tank? I've done a lot of reading and have not seen any definitive solutions.

For an example of the rays handy work, see below.

 

[FishEZ]

I have experimented a lot on different things to get rid of that brown paper off the bottom. Believe it or not, so far I have found that gasoline works the best.

 

[marsh1n]

I have experimented a lot on different things to get rid of that brown paper off the bottom. Believe it or not, so far I have found that gasoline works the best.

The tank is already set up, so I was looking for something to put on the inside of the tank under the sand.

 

[local hero]

I've used Starboard before (HDPE sheeting) you get get it in quite a few colors.

 

[marsh1n]

I've used Starboard before (HDPE sheeting) you get get it in quite a few colors.

Is that waterproof? I read a lot of posts claiming it should not be kept under water.

 

[local hero]

It will absorb a very, very small about of water. Totally fine though, just cut it a 1/16 to 1/8 smaller than the actual size of the aquarium. Tons of reef keepers use it, most cutting boards are made of it and almost all commercial water holding tanks are entirely HDPE. It is just high density polyethylene.

 

[marsh1n]

It will absorb a very, very small about of water. Totally fine though, just cut it a 1/16 to 1/8 smaller than the actual size of the aquarium. Tons of reef keepers use it, most cutting boards are made of it and almost all commercial water holding tanks are entirely HDPE. It is just high density polyethylene.

Thanks. I'll give it a try.