Thanks, Mom! Good to know. So they are pressure filters. Sounds as convenient as a filter can be! What are the cons?Ultima touts their filters as "biomechanical"
http://www.aquaultraviolet.com/products/filters/ultima2/10000
I plan on using Ultima IIs for biological filtration on my small (compared to your tanks) 1700 gallon tank when it evenutally gets set up.
I must take back my inkling on Vince's filtration. It's not thin at all then.
That's why I told you right away what GPH a 4" ball valve lets through at what head pressure - 15,000 GPH at 5' level differential, remember? Bulkhead would not be far off.... One of my mistakes was using bulkheads that didn't allow enough water to pass... had to add a few more bulkheads because the pump was pushing more water than the drain could handle.
But the "smart" me is sitting in precisely the same puddle, as we say in a Russian proverb. My pumps cause my tanks to overflow because the drain size is too small + the sump is not low enough. I wish I used 6" bulkheads on my 4500 gals, instead of 4".