I have mine about in the middle of the keg. Dont go too far up otherwise you cant use it on 5gal batches. I would put about 5 gallons of water in your keg to find a good location so that it hits right about under the surface. Should work fine for 10gal batches this way as well.
With mine, i dont have any sort of filter on the pickup tube.
Resistance Brewing Co.
Resist Crap, Drink Craft!