Hi, my daughter too had the same problem with too much foaming. After trying both the Pari and the Sidestream we were told to use the regular ole disposable nebulizers. The same as someonelse mentioned, roll the vial, do not shake to mix. Also, if you are adding saline, stop adding the saline only use the sterile water. You can also add your albuterol to it, not the premix. This is what we were told last year. We have been doing it this way for a year now. It cut way down on the foaming. We mix up each days use in the AM, so the evening dose has already settled. We have since changed back to the Pari and haven't had any problems with excess foaming. We were told the saline really gets the foaming and bubbling going and that it was OK to not add it. We mix 2cc sterile water to the colistin in the vial, then add 2cc sterile water in the neb. with the regular dose of albuterol. Check with your clinic first though. Liza