300G drains...Should I add another?

Sphinxj13 · Jan 17, 2026

Looking to see what everyone's thoughts are here. Water film buildup in the center. 8ft 300 gallon mixed reef currently set up and running with drain and return in each corner. I have MP40 on each side with reefwave 45 in the center of the back wall. I used more powerheads here in the past but removed them bc it was just too much flow. Unfortunately since I've decreased the flow some things seem to be much happier while some LPS hated the change. Im debating on drilling another hole in the middle to add another drain since everything gets blown towards the center. What's everyone's thoughts on running 3 drains and 2 returns?

Reefering1 · Jan 17, 2026

Aim that pump, in the rear center, up- towards the surface. Add another pump to fill the void that move leaves.

keithw283 · Jan 17, 2026

You could always add more pumps and just lower the percentage on each pump. I have an 8ft 240 with one center overflow box. I had this same issue. Both return nozzles are pointed towards the surface across the back wall of the tank and I have an mp40 on one side and a gyre and mp40 on the the otherside. I also bought 2 dmp55s to add to the back wall to fix this problem but never added them as I was able to do it without. Just play around with placement and power. Shouldn't need another overflow.

Sphinxj13 · Jan 17, 2026

Reefering1 said:
Aim that pump, in the rear center, up- towards the surface. Add another pump to fill the void that move leaves.

This was what I was trying to achieve before and flow just got out of control imo. I was running an mp40 on each side, and 2 reefwave 45s on the top of back wall towards the middle and an mp40 on the back wall towards the bottom corners. Now the mp40s are on the side about 3-4" from the top and if I crank them up to fix the center the middle area gets pounded. And if I cranked up the reefwave on the back wall the the flow rolls off the front and pounds the sand. But its sounding like the drain amount is fine and still just have to figure out placement for the center

Sphinxj13 · Jan 17, 2026

keithw283 said:
You could always add more pumps and just lower the percentage on each pump. I have an 8ft 240 with one center overflow box. I had this same issue. Both return nozzles are pointed towards the surface across the back wall of the tank and I have an mp40 on one side and a gyre and mp40 on the the otherside. I also bought 2 dmp55s to add to the back wall to fix this problem but never added them as I was able to do it without. Just play around with placement and power. Shouldn't need another overflow.

So you're thinking I should just point the returns towards the middle top center and let powerheads worry about the sides