as other guys already mentioned -- don't worry, algae won't be able to tolerate the temperature and pressure within the cooling system of (any) car
..and since there is discussion related to cooling system. I've something weird to discuss here.
Lately, I've noticed that the temperature needle, when it reaches almost to the middle of the dial. The fan kicks in, runs for a while, gets turned off, but the needle doesn't budge. Not even a little, it stays where it is and the auto fan keeps on cooling after every now and then (as it should).
But if i stop on the road side for a min and pour some fresh water on the radiator (while the engine is running), the temperature needle will come down considerably.
what are your thoughts guys? I'm suspecting bent fins, a little clogged radiator, or slow fan!