My $.02 worth. I have a DIY all glass 39g. with a DIY RUGF (air driven). I
used regular window screen (plastic? fiberglass?). This tank has been
running for 4 mo. and I have had no problems with my fish (swordtails,
danyos, cory, gorami, USD catfish). I use 1/8" and 1/4" gravel from a rock
suplier. $15 for 80 lb instead of $15 for 5 lb. from the petstore. Plus it
looks more natural. Lots of different colors. I haven't checked you but I
don't think that my plants have dug through yet. Smaller gravel will clog
faster and there will be less flow.