Pro Clear 150 w/skimmer

I bought a pro clear 150 sump system with a skimmer built into it, I was wondering if anyone can give me any advice on knowing when or how the skimmer is setup correctly. When I have the skimmer pump running i get lots of clear water in the cup and very little protien. I just do not know how to tell when it is setup correctly. I need to know how far up the neck of the skimmer the bubbles need to come up. Please help.

Thanks

 

Secondly

I know this is the wrong place to discuss this but I am also having a algae problem too, I am going to put pictures up of my tank and hopefully someone will be able to tell me what is wrong.

I went and bought 40 blue legged crabs, 20 small snails, and 5 large snails, I have one blue damsel in the tank as well

Water Parameters are
Amm. 0
Nirtrate 0
Nitrite 0
PH 8.2
Salinity is 1.025 ppm
Heat is at 78

 

How old is the aquarium? What size? It doesn't sound you have much of a bio load on it, and if it's fairly new there probably isn't anything to skim. You should adjust the skimmer until the bubbles are about at the bottom of the small overflow tube. When there's enough organics present for the skimmer to work, the foam will start rising up and into the collection cup. I'm not familiar with that particular skimmer, but most have a water level adjustment.