just finished a new indoor wooden tank. I built this for several reason, most to prove or disprove some common theories. The tank is 4' wide, 4' high and 25 feet long. It is a "River Flow" design with massive current all from one end. Two bottom drains at the "Dead" end supply two Evolution ES 8500 pumps each feeding a set of my fiberglass showers with feather rock. At 2 feet of head these pumps should be good for close to 10,000 gph each, all shooting out from the "Live" end.
A skimmer at the dead end feeds a Evolution ES 4500 pump feeding two of my sand/gravel filters. This will give me a total flow of around 25,000 gph, all from one end.
The showers will provide the bio and the S/G filters will provide fines filtration.
I used one of my custom "Drop in Liners" for this which made liner installation a breeze.
My "Tests" are
How fast and well with the feather rock showers cycle?
How much do the Koi actually like fighting the current?
What I have found out so far is using bottled ammonia @ 3ppm I had nitrites at 4 days and nitrates at 6 days.
I can also see the current breaking the surface about 12 feet from the live end. I won't be putting my fish in here until this fall so the swimming test will have to wait a while.