i have 1 x 22mm pipe draining water from my tank to a container below my tank which i am setting up as an algae scrubber, my tank has about 500L of actual water, i made the screen out of a tank sepetator and 8" wide x 12" deep, i cut the slot in my 22mm pipe about 2mm wide, however i am finding that not enough water is flowing out the slot into the container to keep the return pump going with water,
what can i do to get more water flow out of my pipe and into the container ?