can rays live on gravel?

[shekes]

An empty 135g (63”x 28”x 18”) is waiting to be set up in my living room. A 14” black arowana will be its main inhabitant. I need help to decide on its tankmates.

I was thinking of buying one or two Potamotrygon motoro (or hystrix). But I have everything ready to put in the UGF and no sand for the rays.

So I am not sure whether or not the motoro can live on gravel, and, if I do get sand: How do I clean it?

[redtailfool]

if the gravel has no sharp edges then they sure can. As for sand, make sure its non silica based and the way to clean it is to just let the siphon "hover" over the sand.. that should be enough to suck up the dirt above it.