[toddnbecka]

I've seen some sad-looking HOB impellers hanging around the lfs, victims of death-by-sand. I'm wanting to switch a 30 long from gravel to sand substrate, and wondered whether a fluval 305 or an eheim 2224 would be safe to use (w/out buying new impellers weekly)?

 

[xenergyx]

A sponge pre-filter on the intake and the canister's filtration itself should catch the sand before it ever reaches the impeller...

 

[natalie559]

On most canisters, I know for the fluval, the water (or sand) must go through all the media baskets first before it reaches the impeller. This combined with a prefilter should give you no problems. Keeping an extra impeller on hand is a good idea anyways though.