ac7av
Bring on the FISH!
Well my personal opinion then is that the using of the ¾ inch tees are just too small. I don’t know why you would need to downsize them unless it’s a space issue in your box. This mode will work the same with any size box and tubing and making the size smaller will only reduce the capacity of the over flow box 1200 to maybe 600 gph. The inside diameter of 1in vs 3/4in is like close to 50% reduction in volume. You are simply over running the mod on your overflow box. I have a 1 ¼ line in my overflow box and have a T connection on the top with two 90s on each side that point down with a small hole drilled in the top of the center of the T.