trickle tower under 500gph ,bakki 500gph +
bakkis all the way , you wont find a better way to filter your pond , and the DIY jobs work just aswell as the shop bought ones
the only problem with useing K1 , is it does have a tendency to block up !! though i do love the stuff , you might be better going crystal bio or biopore .
the trick with bakkis is to get the turn over right , the smaller the pond the faster the turn over , on a 1500 gallon pond , i would aim for 3-4 times per hour min . also the faster turn over is based on fish stocks .
i used to run my 5000gln pond on 5-8 X's per hour , i now run a 12,000gln pond , with a 12ft 4 tear bakki , with a flow rate of 130,000lph
steve