Just so agressive

[poochieandi]

I was told everytime he barks at another dog to throw a small water filled balloon at him which I didn't like to do.

A water balloon is a definite no-no, for one reason it is way too bulky to carry around in walks plus can be very messy, most of all it will not only startle him, it will hurt him (like when it bursts on his face- ouch!) and can seriously turn on negative emotions at you. So, good that you are not into it.

If introducing him to other dogs in a little-by-little manner does the trick, then stick with it. A good recall training can also be of help along with catching his attention each time he starts barking at another dog and making him busy on some things that you have taught him like "stay" and "sit." If he is obedient then. Reward him.

[Cataholic]

Is he neutered?

Does he spend a significant amount of time behind a fence? Is he walked on a daily basis, with plenty of positive reinforcement for nice behaviour?