Okay, wait a minute, are we talking air or water? I guess I misunderstood the tread..."roger" mentioned air and I just ran with it...I actuall haven't heard of ap100....
okay, reset.
75L of k1 is....nearly 20 gallons....thats a LOT....or is it pounds? 75L equals...
Anyway, it's quite a bit and my confusion doesn't help...
it has been my experience with fluidized bed filters that a water pump moves the media far better and waay quieter than air ever would. I would get a QuietOne 3 or 4,000, pinch the discharge side down with a valve to adjust flow and a small airpump to introduce air into the media....