[glampka]

The 802s are probably the Aquaclear 802 powerhead. If the water is coming out the front it will be sucked in through the bottom. Fish/shrimp, etc can still get caught up against the guards (not too likely though). You could take a short piece of 1" tube & drill a few holes in it & put the ph into that for further protection or you can get the sponge filters but be sure to clean them every few days since they will act like a mechanical filter.