Algae or brown encrusted dirt?

[charsand]

I have attached a picture of my thermometer that has an encrusted brown coating. It is not slimey. I was wondering if this is dried out algae or just dirt of some sort. It was like this when I took it out of the water before I started my slam.
Thanks
Charlie

 

[Texas Splash]

So it was in the water and already hard and crusted? If so, that doesn't sound like algae. Maybe some scale or something. Maybe you could post a full set of test results? That may give us more clues. Have a nice weekend Charlie.

 

[woodyp]

Is it anywhere else in the pool? And is the exterior of it metal or plastic?

 

[charsand]

It is also on the Polaris....both are plastic.

 

[duraleigh]

Looks like scale to me but it's all just total guessing until we can have a complete set of current test results. That'll give us clues to get started.

 

[JamesW]

See if it will come off with vitamin C. Then try vinegar (just on the thermometer, not in the pool).