It took well over a year to finally get coralline algae to grow in my 24 gallon AIO cube. I never added any of the coralline additives on the market, just waited for the purple stuff on my snails to take off. I was thrilled because the consensus is that coralline is a sign of a mature, stable tank. Yay!
The CA took off, covering every rock and the back wall. However, I noticed that there was an upper limit to the coralline on the back wall. It abruptly stopped about 4 inches from the top. It is as straight as a ruler, without a single spot of CA above. I first thought maybe it was a lack of light, so I adjusted the light to make sure the top four inches were well lit. It made no difference. The CA refused to grow above this apparently arbitrary line.
Then I finally saw what was causing this strange phenomenon. When I do a water change each week, I remove 5 gallons. That is the line! The coralline apparently cannot tolerate being out of the water, even briefly (20-30 minutes).
Has anyone else noticed this in their tanks?
The CA took off, covering every rock and the back wall. However, I noticed that there was an upper limit to the coralline on the back wall. It abruptly stopped about 4 inches from the top. It is as straight as a ruler, without a single spot of CA above. I first thought maybe it was a lack of light, so I adjusted the light to make sure the top four inches were well lit. It made no difference. The CA refused to grow above this apparently arbitrary line.
Then I finally saw what was causing this strange phenomenon. When I do a water change each week, I remove 5 gallons. That is the line! The coralline apparently cannot tolerate being out of the water, even briefly (20-30 minutes).
Has anyone else noticed this in their tanks?