Little bubbles... or micro bubbles?

[RLG2182]

So many questions... so many questions...

So my brother gave me his old CPR bakpak unit (the one WITH the bioballs) and tested it out in a tank with tap water. No matter how much I fiddled with the air nozzle, the bubbles only stayed "small" ... not micro tiny like I see in some LFS big units. They resemble bubbles out of an airstone or a strip of bubble wall.

I also happened to pick up an Amiracle 3000 skimmer on ebay for super cheap, and same thing... no matter what, bubbles are either "small" or very occasionally tiny, but just every now and again.

Is this normal? Will results change in salt water instead of clean tap? Not sure if these sized bubbles will even skim anything. :?

 

[phases99]

Your skimmer will not properly foam in fresh water. You will see it in action if placed in salt water containing dissolved organics.

 

[RLG2182]

Ahhhh... well wasn't so concerned with foaming in fresh water... was just freaked that the bubbles were so huge.

Thanks for the advice so far!