Once the water leaves the pond via the bottom drains, it goes to 2 separate vortex systems. These DIY vortexes where made from bulk kitty litter hoppers. They are 30'' in diameter and overall 32'' high and the price was right…$50.00 Can.     The straight part of the cone is 19'' and then it tapers to a 3'' bottom.     The tops where removed and the tangent holes were cut into the bottom of the straight side and outlet holes in the back. Then 4'' pipe was fiber glassed into these holes. A 3'' fitting was also fiber glassed onto the bottom, for the drain lines.

The water leaves these vortexes by overflowing into a 4'' pipe in the center of the cone.

Once the water leaves the vortexes it goes through 2 barrels which... the 1st one has mats of open pore foam,  then the 2nd one has Japanese Mat.

After the water has passed through the barrels it then enters a common 5th barrel. This is where the pumps are located. The only way to feed a new 4100gph pump, (it's on order), enough water, was to tie the 2 systems back together at this point.It also slows the flow rate into the vortexes down.

2 -TT's, one 15'' dia. and the other 20'' dia., also draw water from and return it to this barrel.    The pump for the UV is located in here also and it feeds back to,1 of 2, TPR's, tangental pond returns.These give the water in the pond a swirling motion, forcing the crud to the bottom drains.     A 3rd vortex, not shown, is fed from the surface skimmer. The water retun here is also back to a TPR.      For the moment another submersible pump feeds a 4'' pipe high on the wall that goes back to the water fall. A lot of the pumping will change once the new external pump arrives. Not sure what all this cost, probably don't want to know, but the pond a crystal clear, with no crud on the bottom. It works!!!!!!!!     G