What is the white fungus-like stuff on my fish tank's interior rubber surfaces?

It grows on the heater and thermometer suction cups etc and really unsightly. Is this a form of algae? Why is it only on the rubber parts? What can I do about it?What is the white fungus-like stuff on my fish tank's interior rubber surfaces?
that is perfectly normal for the tank and the accessories to have that build up. Try and put it in a place where there is no direct sunlight. Sunlight promotes algae and mold growth on fish tanks. Also, get a good filter for better water circulation which also prevents algae grownth. Tank cleaning is needed at least once a month.What is the white fungus-like stuff on my fish tank's interior rubber surfaces?
It could mean you havent cleaned your tank well, you have to srub the iteams in the tank very well. DO NOT USE SOAP!