We never did recommend or use Formalin or any sort of chemicals which are considered of high safety risks.
Stripping down the unit to a certain limit can be performed once a year. We have used pre-sept tablets (Bleach Tablets), one tablet per 1 to 2 liters of water depending on the severity of the case. Rinsing with sterile water using steril wash clothes.
From time to time, we add a mix of viniger & water to the reservoir and run the Incubator for few hours to remove any builds up of calcifications.
Hope that helps
Regards to all
