you have to take into consideration the height that the pump has to overcome to reach the outlets...that's called headfish-boy13;2216800; said:Hmm found this site http://www.marinedepot.com/ps_AquariumPage~PageAlias~powerheads_pumps_danner_mag_drive_supreme.html
seems to be at 1800GPH.
Now i dont have much experience with pumps so its hard for me to estimate whether its enough or not.
you have to take into consideration the height that the pump has to overcome to reach the outlets...that's called head
On this type of system that you have, you want more water to leave the tank than you can return with the pump...this way you won't overflow the tank.
The "T" is there to help reduce the amount of gurgling and possibly a siphon break. I don't see much purpose in this with the fact there should be no siphon involved in this type of overflow setup.