Thankfully in hydro, we have no beneficial bacteria. It's just chemicals. In-line UV is safe. It's also expensive and unnecessary, though.
I buy the bottle of algae killer from wal-mart for $5 and just a few drops each week keeps it clean. The bottle should last you a year for normal sized grows. If you have any other buildup problems, you probably need to clean your Hydroton. Shit is dirty from the bag, takes a bunch of baths to get it from silt coated pebbles to pebbles. Nothing else should ever be a problem in your buckets, lines, or system.