Hi Joelan
This was not posted as an affront towards Jeff or his work. If ootyboy would have stated the idea of the backerboard in his first post, I wouldn't have mentioned it. It's obvious, like the rest of us, he'd like to have a nice pond, but nice ponds don't come cheap. Nice ponds are CORRECTLY BUILT ponds and the structural integrity was the issue I was discussing. So, no need to get defensive here. Just trying to help the guy get off on the right foot the SECOND time around. I just have to agree with Russ and Misterseed on the main structure that is in play and his ideas about filtration.
Ootyboy
Forget the other discussion on the other thread and think your filtration through before you end up having to change it a third time. First off, how many pumps and what size do you plan on using - one? I imagine it's probably at least 1/3HP to run the 10000Ultima in line!? They run about 3.8-4.5 amps. You could use the same amount of basic electricity with two pumps - one for the main circuit to jets and the other from the skimmer(s) to the Bakki showers once they're installed. This is also for safety sake when it comes to your filtration. If one pump goes down, you still have one circuit running part of the system. Then there's no need for the Ultima 10,000 to be used. Therefore, no big head loss from a pressure filter!!!
Also, if you use your vortex as a settlement/mechanical filter, your second chamber would provide a much better bio function without collecting as many solids. Simply add a round "blue" Matala mat on top of the settlement chamber and gravity feed to your bio from above the Matala. Works much better when using only two chambers and it's easy to clean. As you're not worried about it's use for bio, just hose it off when you dump the settlement chamber and you're good to go.
Also, I forgot to mention one other thing - the bottom drain. You mention that you were going to go with the Rhino. Have you checked out the DreamPond "Koi Toilet" Bottom Drain. They're half the price. Also, in case you ever need to replace the air diffuser, it simply unthreads from the dome. They cost around $40-50. If you need to replace the diffuser on the Rhino, I understand the cost is around $140 as THEY ARE THE DOME. Oh, and you'll have to figure out how to cut the air line to it as well, which comes in from the side. A poor design in my opinion as the tubing can catch algae and leaf debris and reduce the performance of the drain line. The Koi Toilet gets it's air supply directly through the standpipe which comes up through the bottom of the unit. The bowl is also just that, a rounded bottom edge BOWL, not a squared off finish inside. This all can detract from the proper flow you want for your drain line. Just food for thought, especially if you're trying to save a few bucks here and there like the rest of us!
Mike