Need help with Brine & Slow rinse time calculation

[SoftenerNewbie]

Runxin Up-flow regeneration valve: https://www.run-xin.com/upload/20190627/153734581337.pdf
Purolite C100E Resin: 2.5 cu-ft in 13x54 tank

According to resin datasheet, I need 0.25 - 0.5 gpm/cu-ft of Nacl/Brine injection. That means at 5 liters/min, the required brine (calculated at 8lb/cuft) will be injected in less than 7 mins (Brine and Slow Rinse in 21 mins). But according to data sheet Brine should be 20-40 mins. How come my brine time is coming up so short?

Should I get injector with even lower flow? Even at 3.5 liters/min, Brine injection will be 7-8 mins. I feel like I'm calculating something wrong?

 

[SoftenerNewbie]

Would really appreciate if someone can help me with calculations, as its been a few days and I'm totally lost. I feel like I'm doing it right but numbers don't make sense.

 

[Sponsor]

 

[SoftenerNewbie]

Finally heard back from Runxin so sharing info here, in case anyone else runs into this issue:

For each injector (depending on the tank size):
Brine injection rate = Total Flow Rate - Slow Rinse Flow Rate (Water)

So for Blue injector. Total Flow rate during Brine and Slow Rinse is 3.99 Liters/min of which 2.46 Liters/min is water, so 1.53 Liters/min is Brine being sucked into the valve. At 1.53 Liters/min my calculations make more sense now.