Solar panel installation question

[matt4x4]

I got most of my information from a friend who is an environmental engineer - he spends most of his life designing cleanup systems that require many miles of plumbing/extraction chambers etc and intricate measuring devices.
When we researched and purchased our systems he even went as far as calculating the cross sectional area of the tubes to see if they equal the supply line (1.5") cross area (which ours did).
I don't want this to get arguementative, since I hate nothing worse that threads going that way. However, just how would the backpressure increase by running MY panels in series, I'm not reducing my pipe diameter anywhere along the route (except the return valve, but that is standard for all systems, so really, that's where my increase in backpressure would come from).
I'd have to say in your setup's case, you've obviously proven that the panels are restriciting your flow - thus the 6gpm vs 12gpm output (and likely creating backpressure) - maybe the cross sectional area of the channels in your panels do NOT equal the cross sectional area of your supply piping, has anyone calculated that at all? If that's the case, then yes, run them in parallel to keep the same flow rate as if they were not in the picture, however, if one panel has the same cross sectional area it should not reduce your flow rate.
if I were to parallel my panels I'd be efectively increasing my pipe diameter and possibly incur the issues that can potentially go unnoticed as I mentioned in my earlier post, running my panels in series allows me to catch anything almost immedialtely...at worst after a backwash cycle.
Obviously, differences in equipment and manufacturers have different outcomes, and if sungrabber recommends it, tehy're probably right - they designed it, our panel manufacturer obviously has different panels.

[cleancloths]

I agree with you, we don't want to get argumentative, we just want to debate facts and learn from what each other is doing.

When you have many small tubes that equal the same cross sectional area of a larger pipe you do increase resistance to flow. 100 small pipes with cross sectional area of "X" is not equivalent to one large pipe with cross sectional area of "X". That is because there is much more surface are in all those small pipes and you end up with laminar flow at the walls of all those tubes.

Now the difference may also be in that I am running just a small slip stream of the total system flow through the panels and am not trying to run the entire pool flow through them. But that aside, you will always have less pressure drop in a parallel system than a series system. BUT bottom line, if your setup works well for you that is great. I would like if you could post a picture or schematic of it similar to the manual I posted so I could get a better idea of how yours is set up.

Thanks