sand dollars in aquarium?

[moby]

I was lying in bed last night thinking of new things to do with my tank and it occurred to me I have never heard of anyone using sand dollars to keep the sandbed clean.
Has anyone ever done this?
I would think they would be ideal since they are obviously peaceful, live in the surf zone so they are used to changing water conditions and their burrowing in the bed would be ideal to keep it gently turned without disturbing any of the rocks or creating sand storms.
Any thoughts, anyone tried this or seen them even for sale?
Moby

 

[ophiura]

It is definitely a bad idea. I strongly discourage it. They will not keep a sand bed clean. They burrow into the sand at an angle, so the bed needs to be deep. Also, some species require silicious sand over carbonate sand. Particle size is also critical. Long term survival is not good. Definitely not recommended

 

[moby]

Thanks ophiura,
I guess that is the reason they are not kept in the aquarium! I knew there had to be a reason or I would have already seen someone doing it.
Your advice is always welcome and respected. :happyfish
Moby

 

[pyro]

I've always wondered the same thing.
Thanks.