Upside, downside...... and sideways!
Upside is I got the 275 gallon water tank in a steel cage for the filter, and was able to struggle with it enough to get it in place under the gazabo. As suggested (THANK YOU ALL!) I started gathering filter media as I stumbled upon it. The 275 gallon tank has a 6" top opening and a 2" NPT, gate valved outlet at the bottom. Set where the top is below low water level, it gravity fills to the tank bottom from the pond bottom, exits the top through another 2"NPT fitting over to a 55 gal plastic barrel which houses the pump. Drilling a hole in the bottom of the barrel, the outlet of the large tank was plumbed into the pump tank with a separation plate punched with holes, held the pump a foot off the bottom, sitting on 14" floor scrubber pads.
Trying to make the filter back washable in the large tank, I started filling the tank with large broken up, sharp edged granite chunks that just fit in the top opening. With a single layer of the large rocks covering the bottom, we then progressed to 3" and the down to 3/4" sharp broken up granite, until it was about 20" deep with progressively finer rock. The final filter step in that tank was 5 synthetic swamp cooler water pads that floated up to the top, covering the outlet, with about 20" of clear room between the top and the rocks..... Done enough to try.
Of course, the bottom fitting in the pump barrel leaked and that had to come apart numerous times in an attempt to seal it. In our parts runs we picked up a couple dozen feeder goldfish thinking the toads and water bugs were doing good enough... maybe they too would survive. Lowle's had a 2500 gph pump on clearance so that was picked up for the filter pump.... same price as the 580... soooo, bigger being better....
The bravest of the bunch went swimming to get the valving set up at the pond bottom, (heck no it wasnt me) and the whole affair was plugged in as Kris dashed for the hot tub. No I did not wash all the rock going in the filter tank but we did pay extra to have the tank and barrels power washed very well. It only took a few minutes to wash all the rock and deposit all that dirt into the pond, making semi clear water look like a swamp. Only took one more minute to learn the big pump flowed more than the combined filters, requiring various washers placed under the outlet fillting until one the correct hole diameter was identified that would restrict the pump where it wouldnt empty the barrel.
Left run throughout Sunday... by Monday morning the water was literally crystal clear, once again proving a blind squirrel Can find a nut now and then! Right up until we learned how good the container company washed out the Agave juice from the container.... and what that looks like when it floats on the top of the pond!
The filter WORKS GREAT! Frogs, Toads and pond skaters are loopy on catus juice and all the moths drawn to it. Pump barrel leaks and will require a redesign. Monster 'good buy' pump is restricted down to a 1/4" outlet making that good if for no other reason than to have a spare falls pump. Plans to wet dry vac off the film of catus juice are now being drawn up. The Resident Pond Diver is threatening to strike if I want the valving changed again down at the bottom of the pond again before next summer.... and the project still doesnt have the solar panel worked into the equation. This will NEVER end.... but the filter works far better than ever hoped for, changing it from a swamp to crystal clear in 1.5 days and everyone of the tiny fish have survived for 3 days now. I suspect it will only be a few days before the bears smell the sweet smell of the catus juice... this just cant get any stranger......