knobs on cpr aquafuge?

[reefNewbie]

what are the 2 knobs for on the inlet right above the powerhead. i tried turning them and nothing seemed to happen.

 

[31-2c]

i dont know about 2 knobs, mine has a small ball valve above the powerhead

 

[reefNewbie]

yea, but it keeps turning, so im confused as to if it is tighting/loosening or just open close. but then ablove that there is a tiny little know that comes off if loosened too much.

 

[31-2c]

I forgot about the small one.

The large one is the ball valve. When it is vertical, it is open, when it is horizontal, it is closed.

I have no clue about the small one, I have never used it. It looks like a place to connect an air line for air injection. It has no use on the aquafuge