Algae line on glass

[trip]

Interesting observation after recent water change: there is a perfect horizontal line (as if tape was there)- on glass where water change level was, below abundant new algae growth, above- clear as if recently cleaned. Never witnessed this before-- any thoughts??- guessing something to do with exposed glass above water line during water change process

 

[katebishop]

Interesting observation after recent water change: there is a perfect horizontal line (as if tape was there)- on glass where water change level was, below abundant new algae growth, above- clear as if recently cleaned. Never witnessed this before-- any thoughts??- guessing something to do with exposed glass above water line during water change process

When you remove water, the previously submerged area is exposed to air and light. This disrupts the growth of algae that thrives underwater. Wordle Unlimited

 

[trip]

I have been in the hobby for about 10yrs; this was the 1st & only time occurred- wonder why this time & never before??