| Hi Steve,
I realy like all of Rick's suggestions and as he said you can still use 2" plumbing w/ your existing pump. Just place the conversion as close to the pump as possible. You'll cut your head loss due to friction by half.
I understand what you're saying about getting too complicated with two pumps but you don't necessarily have to change your filtration components. I actually think it simplifies your design. You two circuits could be something like BD > spirex > bio chamber and skimmer > ultima > UV. The advantage here is that you have the greater mechanical filtration where you need it at the bottom drain. You can gravity flow that entire circuit. On your skimmer curcuit, you have you're pressurized equipment. This will allow you to size your pumps appropriately.
I'm not a big fan of matala for mechanical filtration because maintenance is such a manual process. Have you looked into building a DIY microscreen? It seems like that would be the ideal solution since you already have the spirex settlement chamber. Another option that is a simpler DIY project would be a static media filtration such as an Eazy. Both of these options would be alot easier to clean than matala. On the microscreen, you would just need to flush the settlement. On the DIY Eazy, you should just boil the media and then flush the settlement. A few minutes tops, no need to get wet.
For the skimmer, you can use an in-wall pool skimmer on the pond instead of a Savio. Using a pool skimmer gives you a small footprint and gives you alot of flexability.
-Dan |