well now were talking speakeraddict.
humboldt reefer, in my specs for the auger i called out a 12" OD on the tube that the auger will go into not a 6" one, so, if possible it would be nice to use that size, i can probably work out a deal to get some 12" or similar size SDR pipe from HCSD, i know a guy who works high up there, that will save on the cost of acrylic tube. now for the motor issue, this will be the biggest problem, but i will do some leg work to find out a source and price
it's starting to look like this DIY project will really work
oh yeah, H reefer, how you gonna get your 210 drilled for 6" bulks

i think K7N glass will be in over their heads, j/k but it would be nice to see the look on their faces when you ask them to drill for a 6" bulk, personally i think you would be better off using 2 or 3 3" bulks because you could use standard abs fittings and save some money
and just think, if we can get the kind of flow we are looking at getting then this would be really the only means or circulation you would want, maybe a few seios or something on a chauvet timer like i use, set mine to switch at 3min from channel to channel, and even if the dc motor draws 500w you would be way way way more efficient then a big closed loop that would give you gph in the 20-30K range
Tim