head loss calc

[myfrostymember]

ok i have been inputing some numbers in the calculator on the home page and i am having some questions. The calc doesnt really say much about anything other then bam the answer-- so for instance a genx mak 4 does around 1200 gph at zero head and a mag 24 does 2400 at zero head but after adding a little head and some 90 elbows the mag24 falls to 1300 and the same numbers on the genx mak4 only fall to about 1100- so why does one fall so far and the other not? how acurate are the number? and how acurate are the numbers on having multiple outputs? if it says the genx will do 1100 and i have 3 outputs i can just divide 1100 by 3( not perfect but close).

using pumpo for a closed loop with 3 outputs- the mag 24 is a little much so im downgrading but i dont want to downgrade to much ----mak4 a good pump for a closed loop? its semi-cheap and decent pressure

thanks matt

[myfrostymember]

anyone use this head loss calc and know how reliable it is with diffent pumps?