The pull depends on the proportioner design, where did you get the plans for that? There are two good threads on her about proportioners, one by a guy who sells them, and another by a guy who was building one but left the industry during its trial period.
I’m not good with names and can’t look it up this instant.
Also that SH tank will probably leak eventually, you don’t want any holes but rather pull chems from the top.
I don’t use an air diaphram pump so I can’t help you there.
Before you purchase a PW be sure to read this forum for a few months to find out which one to buy
Edit1: Pro-Mix-Alot V2
Edit2: DIY Softwash Metering System
