I may be wrong about this because I'm still just learning this stuff myself, but:

Generally distilled water carries no current.. But, with the addition of some acid solution, it becomes an excellent conductor.

Adding acid to water causes the Ph balance to go up. I've done it countless times for pools and fish tanks..

Once you get the proper solution that is working for you.. no matter what electrolyte you use it is good to check the Ph balance of the water...

It is easy to check the Ph of the water. Get one of them pool tester kits.. About $6 at wal-mart. Just fill it with a sample of your HHO Converter water.. put a couple color drops in and match the water to the color chart. It will tell you what your Ph is. If you want your water more acidic.. you can raise the level up with the Ph Booster drops that come with the kit.

Of course in pools you can't use the little drops, but, in an HHO Converter you deff could.

The Ph Booster in those kits is used for fish tanks, so it is probably environmentally safe.. and only a couple drops will really boost you acid level up.. A couple drops will boost gallons.