Herbie's can run just fine with tee's on the return line. It will just require a little extra tuning on your drain valve as you turn your 'extras' on.

Keep the pics coming!

This is a pic of the tank during water test. I left water in it for almost a week to see if there was any settling that would cause my drywall and mud to crack. And it never moved one bit so I finished with the mud and paint. I also put up my lights.
http://i1383.photobucket.com/albums/...pshsitthl1.jpg
http://i1383.photobucket.com/albums/...psuukx79sy.jpg

If your interested in seeing better close up pics let me know. Just after I finished painting the wife said she wants to reprint the hole room. I still have more pics of the sump and water mixing /water change system that I'm currently working on but had to order parts for it from j&l.

I purchased too tanks from marmit plastics 30 gallon each tank for ro-di water and saltwater storage
http://i1383.photobucket.com/albums/...pstcxdchil.jpg

I started some of the plumbing for my water storage and mixing. The plan is too put a mag 18 external on the floor to transfer di water to saltwater tank. To mix the salt water tank. Also to drain water from sump into floor drain and to refill with salt water. This pump could also be used to back up my mag 24 in the sump if it ever quit. I also have parts coming for overflows on holding tanks
http://i1383.photobucket.com/albums/...psn3wc4ywr.jpg
http://i1383.photobucket.com/albums/...psy13h1hvz.jpg

Love this build, looks great! The only time you run in to serious issues with a herbie (as far as I know) is when you start adding T's to the drain line. As mentioned, the pipes attached to your return pump don't affect it beyond the fact that any add-ons and doodads connected to the manifold will affect your flow rate, so if you get it all tuned up then disconnect a GFO reactor to change the media out you might see the water level in your overflow rise a bit until you put the reactor back online.

Another problem I have is a noisy mag 24 it's brand new but it seems a bit to noisy for me so when I did the test run I raped it in bubble rap and it was quieter so now I have peaces of foam sponges around it I have yet to try it. I might try some wet suit material but I'm open for suggestions.
http://i1383.photobucket.com/albums/...psbu8ttzzz.jpg

So the past few days I've been working on my tank plumbing. With the system I built I can do ato , mixing, water changes , water transfers. http://i1383.photobucket.com/albums/...pswz76whfv.jpg

More pics http://i1383.photobucket.com/albums/...psafvvwqkv.jpghttp://i1383.photobucket.com/albums/...pswvuqejyb.jpg