Skimmer overflowing

i just set up my tank no life just sand and rocks. I bought a reef octopus for it. it sits in 12 inches of water which i think is the problem but it came with no directions but a mark that's says water min and water max and it sit in between that

 

A protein skimmer takes time till it Builds up the foam so in the beginning just turn the valve on top off the intake until the water level drops down to the max line and wait. sometimes it takes a day and ones u see the foam is building up then adjust it again so it shouldn't overflow.

 

its not responding to the valve i turn it off it still bubbles of the top in to the cup which then is full of water

 

Sounds like the skimmer is sitting too low in the water...raise it up a bit...more like 6"-9".
Many skimmers are picky about water depth.

That being said you SHOULD be able to turn the outflow off completely with the valve, but again, it could be water depth-related.

 

i added crushed coral about 3 inches to the bottom of that chamber it seems to work better how should one tune a protein skimmer?

and thank you on your tips

 

Basically, you want the froth in the skimmer to come up to the bottom of the necked-down skimmer throat where the collection cup sits. Let it run a bit and adjust from there to your personal liking (I prefer a drier skimmate, personally).

 

Yup... too deep of water... You know what model it is?