Bubble production

[One_Divided]

I'm in the testing stages of my diy skimmer.. It's a Hot-1/airstone type..

I was testing in freshwater and I noticed that my rio800 rvt and the airstones really don't produce fine bubles at all in fresh water, but blast tons of fine bublles in salt water... Can anyone tell me what determines such a big difference in bubbles?

Looks like I need to make up a batch of salt water..

I'll post a pic soon.