@cleanunderpressure, you aren’t an idiot. But the hastelloy check valves only come in sizes up to 3/4". But having talked to @tireshark, we think a 1" inlet is too large anyway, so I’d have to reduce the line anyway to 3/4" for the barb. The most restriction comes from the metering valves, not the check valves. The 3/4" check valve should be less restrictive than the 1" metering valve, so I don’t believe it’s an issue. I do believe the 1" metering valve is the better option and I don’t think the 3/4" check valves will hinder flow at all.
@topwash, I’m not using the GF valves. If you read through everything, you’ll see where I posted all the components used in a system along with the MSRP for each part and total material cost for each system. The larger Chemline valves are really expensive. That’s where most of the cost is generated from. I could do the GF valves and build one all 1/2" (and I did build one, there are photos, and @tireshark currently has it for testing and comparing with the 1" system). But once I started researching and learning more about all this stuff, I realized that the 1/2" valves are too small and to build a proper system, larger valves needed to be introduced. And there isn’t a large market for larger metering valves. In fact, Chemline is the only company I’ve been able to identify that makes them. Plastomatic makes a different version, but they quoted me over $400 for a single 1" valve. So that’s not an option.