can't understand return chamber baffle

[rseleri]

I'm 1 month into this new tank (first time to have DT/sump) and I just can't understand and maintain water levels..
I read that evaporation results in decreased level only in the return chamber.
I either see decreased water level in DT or the entire sump.
I'm guessing its baffle setting but I don't understand at which height to place the baffle.
I'm attaching a video.
some info:
1. Tank is Neptunian Cube M120, ~400L
2. water level in DT is gently touching the rim of the emergency drain
3. return pump is rated for 8000l/h and is dialed for 5600l/h (i assume im losing at least 1500l/h for all the elbows and height to the tank).
4. second pump sits in the return chamber, pushing water through a chiller and a UV and returns it to the return chamber

Please help meee.

 

[Dread Pirate Dave]

The water level in the DT shouldn't be able to vary while the return pump is running. Over time as the return pump collects detritus and flow slows then the level will decrease a bit since there is less flowing into it.

Once you have chosen a set baffle height the only place your water level will fluctuate is in the return chamber. When you raised the baffle and lowered it again it looked like the water had risen in the refugium chamber, to a higher level than your return chamber? This seems to be working as expected, to me.

 

[rseleri]

The water level in the DT shouldn't be able to vary while the return pump is running. Over time as the return pump collects detritus and flow slows then the level will decrease a bit since there is less flowing into it.

Once you have chosen a set baffle height the only place your water level will fluctuate is in the return chamber. When you raised the baffle and lowered it again it looked like the water had risen in the refugium chamber, to a higher level than your return chamber? This seems to be working as expected, to me.

But where should i put the baffle? And the same level of the water? Much higher so it water will go through the weir of the baffle? Top of weir? Bottom?

 

[Dread Pirate Dave]

That baffle's height will depend on what you are doing with the refugium chamber. If there isn't a need for a higher water level there then the lowest baffle height will work just fine. If you use the refugium chamber to grow chaeto o house additional live rock then you may want it a bit higher.