I've read a thing on Brulosopher's site that irish moss(and whirflock), is useless. What you wanna do is properly cold crash your boiled wort within a short time frame, then lager at near freezing point for couple days before hitting it with gelatin and racking to keg. I do this, and it works...
I check mine at 30 minutes, as by that time most of the starches have converted. But don't stop there, also check your pH at boil and final beer(post fermenation) as well.
You need to go with a 3500 watt unit to properly get a vigorous boil on anything over 5 gallons. I just ordered the Avantco 3500W, but will also need to fork out $100 for an electrician to convert my wall plug to 240V.