Like INdy says you use a low flow power head in the tank or sump to pump water through the reactor. The PBR comes with enough phosban to treat a 150 gallon tank so you may not need to order any PB at the same time up get the reactor. It also comes with a valve to control the water flow into the reactor, this way if you get a PH
that is too large you can crank it down to the proper flow.
Very easy to hook up just follow instructions and make sure you drain off the first 1-2 gallons of water through the reactor.. It will be filled with PB particles and you do NOT want that in your tank.
The PBR is designed as a hang on the back unit so it will fit on most tanks or sumps by hanging or just standing up.
You want just enough water flowing through the unit to get a little movement of PB in the reactor. The top layer will rumble a little and that is good..
worth the $37, I battled cyno on and off for a year and it took it away after a few months.
this is the new unit out now even easier then before...