So I e got the RO/DI unit that generally sits around 50 PSI. I got it second hand and don’t know the exact specs on it, but it pump out roughly 1 gallon every 7 minutes. Comes out 0 TDS and my last resin pack made between 300-400 gallons. My question is, does it really need a booster pump? I know they say that 50 psi is low but it seems to be to be working fine. Thoughts?