Recently purchased an artica jbj chiller 1/4 DBE-200. It's minimum flow rate is 480 gph. I figured no problem my return dc pump is rated for 2000 gph, [ but it also feeds the ext. skimmer, and cheato rector. ]
When I used a empty gallon of milk container to calculate flow rate I was getting only 250 gph @ level 1, and 280 gph @ level 10 on the dc pump. I don't believe there is much head pressure because the chiller is on the floor, and the return pump is in the sump. So then I isolated the return pump, in a test area in my kitchen - on the floor, and discovered that at max rate gph i seem to get out of the pump itself [with the 1 gallon milk carton timed method] is 480 gph @ level 10. So then I started pulling out other pumps from the closet, old ac pumps rated at 2000 gph too, and they too took between 10-12 seconds to fill a milk carton - so only 400 ish gph.
Has anyone extensively tested the flow rate on their pumps? [ I hope BRS does an episode at some point of actual flow rates of various pumps ]
Is this consistent with your findings?
Has any clue why my gph numbers seem to be so low?
Is there a better way to calculate flow [ I bought an arduino flow meter rated up to 900 gph ] - is there any other cheap off the shelf solution to get realtime gph for testing?
I'm testing with a 5 gallon bucket on the floor - I would think that is minimal back pressure since it's max vertical is probably 1.5 feet. about 6 ft of tubing, on the floor for both the in and the out - 3/4 inch diameter.
Do I not understand back pressure correctly?
Do chillers really need 480 gph minimum? Or is that recommendation for a pump market rating - not actual performance? Can I get away with a pump rated at 2000 gph, but real world testing seems to indicate only 250 gph?
When I used a empty gallon of milk container to calculate flow rate I was getting only 250 gph @ level 1, and 280 gph @ level 10 on the dc pump. I don't believe there is much head pressure because the chiller is on the floor, and the return pump is in the sump. So then I isolated the return pump, in a test area in my kitchen - on the floor, and discovered that at max rate gph i seem to get out of the pump itself [with the 1 gallon milk carton timed method] is 480 gph @ level 10. So then I started pulling out other pumps from the closet, old ac pumps rated at 2000 gph too, and they too took between 10-12 seconds to fill a milk carton - so only 400 ish gph.
Has anyone extensively tested the flow rate on their pumps? [ I hope BRS does an episode at some point of actual flow rates of various pumps ]
Is this consistent with your findings?
Has any clue why my gph numbers seem to be so low?
Is there a better way to calculate flow [ I bought an arduino flow meter rated up to 900 gph ] - is there any other cheap off the shelf solution to get realtime gph for testing?
I'm testing with a 5 gallon bucket on the floor - I would think that is minimal back pressure since it's max vertical is probably 1.5 feet. about 6 ft of tubing, on the floor for both the in and the out - 3/4 inch diameter.
Do I not understand back pressure correctly?
Do chillers really need 480 gph minimum? Or is that recommendation for a pump market rating - not actual performance? Can I get away with a pump rated at 2000 gph, but real world testing seems to indicate only 250 gph?
Total length of plumbing and the specific parts used in plumbing can make a difference to friction loss, but the size of the plumbing itself can have an overriding effect. 
