Why arent your protein skimmers bubbles working, making foam.

Okay, these are a few reasons why, none you need to worry about, you just need to fix it or them.
* is it a new tank system that is cycling? if so you should not have a skimmer on yet.
* There can be residual chems from manufacture that will disappear, but you should clean a skimmer before use with dishwashing liquid.
* Not enough life in there to make crap that will skim out.
* is there enough bubble to water ratio.
* Make sure all of the hoses as such are clear and working.

Also with an old skimmer that's not your problem yet, but when the skimmer is dirty it may not work well. With anything plastic, glass or silicon, clean it before using with dishwashing liquid and warm water.