Sump Q: Under/over/under? or the other way?
 

I'm going to add the baffles to my sump. I've added 2 but for the third, I don't know which way to add it. Should I do so the water is under/over/under or over/under/over? Both ways make sense for different reasons. Any help is appreciated.

i think most use the over to control water level.

Yes, this does make sense. I added a pic of the 2 setups and I was going to discuss that further but I think you are right. Otherwise, it might leave the pump dry.

If anyone else has input feel free to add.

Thanks

I ran two baffles for the first chamber under then over, so that the water going thru the sump had less micro bubbles because it pulled the water of the bottom of the first chamber. Then as the water travels thru the sump any bubbles that do make it past the first chamber have time to rise to the surface before the pump chamber. I just built mine in January it’s my second sump and I have been pretty happy with it.

Your first baffle needs to be an over for water level for skimmer.
The last baffle should be an under, to prevent micros(since they rise) and also to prevent return pump from running dry.

You can still control the water level in the first chamber with the first baffle being an inch off the bottom; the second baffle would be on the bottom of the tank and only an inch or so away from the raised baffle. I guess for me Micro bubbles were on of my biggest concerns so I tried to trap them from the start.