New skimmer Yes or No?

As the water in the sump evaporates or changes then the coral life's needle wheel will operate differently. It's a common thing with them. They do work better as a hob cause the tank level doesn't change.

 

That's why the skimmer compartment in any sump should be baffled so that the water height stays the same. The only compartment that should see evaporation is the return/ATO chamber.

 

It's a 250w Odyssey MH fixture, it seems to do a good job.

 

The chamber that the skimmer is in does not change, as Marshall O stated the only place the water level changes is where the return pump is. Quite neat actually, I pour my top off water in the DT and the chamber with the return pump fills up

 

Well that's good to have then. The sumps I had didn't have room for baffles. So the level always fluctuated. Talk about a pia. My sump/fuge I'm getting for this new tank will deff have the extra room. On my old coral life I took the bubble diffuser off & ran the hose into my sock. I couldn't ever get the diffuse to work properly.