bassmaster

Do you or can you use an under gravel filter system hooked up to powerheads with sand or fine gravel??

Jaysee

Welcome to the site. UGFs are substandard filtration systems and are way outdated. To answer your question, no, they can't be used with sand. They really shouldn't be used period IMO.

bolivianbaby

Welcome to Fishlore, Bassmaster.

Unfortunately, I have no experience with sand or undergravel filters, but if you use the google search on the upper right part of your screen, it should help you find the information you're looking for.

Hope this helps

Toddnbecka

Sand will eat impellers faster than you'd think possible. Fine gravel would be better, particularly if you use a layer of bulk filter media (blue/white bonded pad) between the filter plate/s and the gravel to keep the gravel from falling through.

Nutter

Sand is a no no with UGF. It is too compacted to allow sufficient water flow through the substrate. If you use the reverse flow method you will just blow sand all over the place in your tank. Sand will also chew up your powerhead as was already mentioned.
I'm with Jaysee, they just shouldn't be used at all.
If you are dead set on using UGF though, it MUST be with gravel. A grain size between 3--6mm will work best.