Coralline Algae and Air?

I have great coralline growth/expansion in my tank. Sides and back nearly covered.

However I have noticed the coralline growth ends at almost exactly at the level I drain my tank down to for water changes. The growth ends in a near perfect line all around tank.

It seems that exposure to air, even for very short periods of time, stops its growth. :-/

 

I'm not sure I never noticed that as for expouser to air ?? Maybe temporary heat spike from lamps would be my guess ? I know a few places that commercialy cures its l/R out on racks with a salt spray to keep it moist and its corallines good and healthy . Then their L/R is shipped damp and wrapped in wet paper and in a plastic bag . I don't think air cause the problem ? Like on rocks when the tide goes out its exposed but kept damp from spray..

Its like when I hear about exposing Blue Star Lenka's to air will kill them as with sponges also Never had that to happen unless they where allowed to dry up a bit.

As for the water level in your tank dropping when you do water changes I'd guess then you are removing to much water at once if you run a sump.. All water levels are controlled by the sump. I recently asked In-wall if he knew of a method to kill off coralline We maintain a 1,200 gallon acrylic tank that is so covered in the stuff it takes Hrs to scrap it.. We removed 500 gallons to expose the stuff to air for about 1/2 hr it never fazed it ): Corals had no issues with it either..I just wish there was aproduct to kill the stuff off so I could keep the levels for corals

 

any time i ever exposed it to air it died and turned white.strange thing though is that it does'nt die on the live rock when i removed it from water.if i removed plastic powerheads it turned white on them,and if i lowered the water level it turned white on the glass.maybe the thickness of the algae comes into play.tangster said his tank was very covered in it.the stuff i saw turn white was a thin coating.

 

Guess it could be direct exposure to lights w/o water, as I usually leave lights on when doing water changes.

But growth definitely stops at exactly where the water level goes down to when I do water changes (which I usually always do same amount). :-/

I always shut down pumps when changing water so tank water level drops to level according to how much water I am exchanging - (normally 25 gallons)

Yes, I am a believer in regular water exchanges. - better safe then sorry - water params never vary.