Help With Cleaning Water Heater(Aqueon Product)

[BaylorPerez]

so i had noticed a buildup of brown, hard and sticky something on my aqueon water heater(50Watt Automatic heater), i was wondering if it is grime? calcium buildup? or just fish byproducts getting attracted to it and made it get stuck on it.
Also, it feels crunchy as well when i pushed down on it to hard. Im unsure of wether to clean it, or just leave it until i can get more information on what this or it is.
 
(i dont know if you can see it, but its their)

 

[Brodeur30]

I don't know what that is but i'd just rinse it off. I don't think it's a problem as long as it still works

 

[StevenF]

Some bacteria and algae will coat themselves with mineral deposits.  The green spot algae in my tank does coat itself in minerals.  The mineral deposit on your water heater is of no concern.  It will not harm the water heater or fish.   There is no need to clean the stuff off.   it can also  be hard to remove.