New Goldfish Owner

Hi Everyone,

About 3 months ago I purchased my first two gold fish. I got 2
fantail's from Meijer. I actually picked both of them out so I got the
2 that looked the healthiest. I had them in a bowl for about 2 weeks.
I actually started learning as much as I could about them and found out
this was wrong. Now they live in a 10gal aquarium. There is about an
inch of gravel at the bottom, a Whisper 10 (90gph) filter. I also have
a small airstone. My big fish is about 1.5" long and the smaller one
is close to an inch. (the tank is big enough for the time being). I
use the gravel vaccum almost daily to suck up old poop. The water temp
is about 68 degrees.

I am having a few problems that I am not sure if I should be concerned
about.

1. The tips of the fins are white. Its always been that way but it
covers about 2mm of the fin. Is this something to worry about? If so
how can I fix it?

2. The smaller fish has some kind of poop problem. It always has long
poop. I have changed the food, I have even starved them for 3 days
then fed them peas and it poops long peas. I started feeding them
smaller amounts more times a day but I think he got hungry and ate all
the poop cause this morning he must have had a 4" long poop atached.
Any suggestions?

3. My water is always slightly foggy. I do at least 10% water changes
daily and even change more than that once a week or so. Is my
filtration not good enough? What would be the best addition? An under
gravel filter or a second hanging filter?

Thanks for all your help in advance.