Hello,
Welcome to Frog Forum !
Wow -that's some story ! He is a little survivor !

2 VERY important things that should be changed immediately!
1- your frog needs a regular schedule of dusted crickets with a calcium and vitamin supplements or it will develop MBD ( metabolic bone disease) from the lack of calcium. That little squeak you hear when he grabs a cricket could be an early symptom of MBD? Use the calcium daily for a few weeks to get a good start on correcting this. Since he has not had vitamins use them 2 times a week for a few weeks . Then you can switch to vits 1X weekly and calcium a few times a week.
Both of these supplements are commonly found at most larger pet retailers:

http://www.repcal.com/supp.htm#Ultrafine Calcium

http://www.repcal.com/supp.htm

2-You DO NOT want to continue to use tap water without de-chlorinating it. The chlorine in the water will eventually kill your frog as they absorb it through their skin. Purchase any amphibian safe (tap water) de-chlorinator, It's simple to use. ie Aquatize This de-chlorinator needs to be in a soaking dish at all times that is changed daily and not about the frogs's chin. You can review the care sheet below-- I do not believe additional water is necessary except for the a very important soaking dish.

Here is information and a review of a proper set up.
A care sheet for Pacific :
Pacific Tree Frog

Lynn