hard to determin with a system like this as each output is basically a crushed peice of PVC and the average person can't calculate the opening size, not to mention that doing this for each one (since all are different) is really not an easy task for the math impaired LOL...
Basically using this method would be perfect if your using some type of reducer or an actual jet head...
Oh and Oii ... just remember ... pix or else Dr will have to use that Ban option
As you can see its not that powerful but once I put the 290gph powerhead on there I think it should be fine, I only have a 170gph power head on there right now.
That looks great. Once you get that stronger powerhead on there that'll be plenty of jet to push around the dirt and food and poop that you want to end up in the filter.