Coralline Algae Flaking off Glass

[rc1626]

Starting to notice the back glass of my tank (standard 120) no longer is fully covered in coralline algae. It's flaking off in spots and I'm not sure why. It was solid for a few months. Nope, don't have any urchins a I know they will eat it. CUC are hermits and snails (Mexican Turbo and Astraea). Within the last 2 weeks I changed my lighting from 2 x 250watt Radiums to an 8 bulb T5 setup with ATI bulbs. Alk has been a little up and down. Recently it had gotten as high as 9.6dKH and now I have it down to a pretty steady 8.0 dKH plus or minus .3dKH. Mg usually sits around 1300 and Cal has been on the high side the past month or so at around 475.

Not sure if it could be light related or possibly Alk related or maybe something else.

Any thoughts would be appreciated.
Thanks.
Rob

 

[rc1626]

I was just observing that the spots where it is flaking is turning brown and what looks like bubbling is occurring. Just wanted to add that in case it helps.

 

[rc1626]

Anyone?

 

[wkscott]

There are many species of coraline algae. Although they may be the same color and look identical, each species has its own light preferences. When it comes to light many of this algae is more sensitive than coral. Changing your lighting, especially increasing it, can kill it quite quickly. Don't worry though your tank probably contains strains of coraline that prefer higher light. These stains will now take over.

 

[rc1626]

Thanks for the reply Wescott. That definitely makes sense that lighting could be the main contributing factor. Just wanted to make sure it wasn't something predatory or something with my water chemistry.
Thanks again.
Rob