Quote Originally Posted by BigDave View Post
Higher flow will provide better heating than lower. The goal is to move as many calories from the collector to the pool. Lower flow will give a higher change in temperature across the collector but higher flow will move more of the available heat into the pool. Use as many parallel tubes as possible for highest possible flow.
You said move as many "calories" I'm guessing you mean gallons?

So I get the use as many parallel tubes, but what size is typically optimal? Based on higher flow, 1/2 - 1" is probably best?