filter question

[Just5398]

I just bought a new filter for my 20 gallon tank. I bought the Penguin 200 Bio-wheel power filter for up to 50 gallons and it says it filters up to 200 gallons per hour. Will that work well if I fully stock the tank? I understand alot depends on my PWC and maintenance.
The other question I had was the intake tube reaches all the way to the bottom of the gravel. .. Is that too low and what is the optimum height for the end of the intake tube?

[Weezer]

That filter should be fine,I set up the intake tubes to be about in the middle.Does it come with a intake for the middle..remove that and you'll have about 3 inches less.