Thanks, I appreciate the info. This manufacturer claims their Katalox system only requires 5gpm backwash @ 75 gallons per backwash which, with my numbers, they'll preset for every other day. In the end, I have no idea whether this will work or not as they're all believable to a novice like me.it's about the force needed to sufficiently backwash the iron sediment from the air injection filter. It doesn't have to go for long - it only takes about 150 gal to do the backwash. But it has to be done forcefully to prevent the media from clumping. I suspect you could find a air injection filter that would backwash sufficiently at 6gal/min, just make sure that you talk to the manufacturer and get their input.