Calc, Alk and Coraline

[ERICinFL]

How much of a role does Coraline algae play, in the depletion of calc and alk in the aquarium? Right now, I let it grow on the back glass of my display tank, all in my sump and of course, my LR. I've got a 20L sump and I'm wondering if I scrape the Coraline off all the surfaces and keep it from growing, if there will be less of a depletion. Thanks.

[Randy Holmes-Farley]

Coralline algae can be a primary sink for calcium and alkalinity in many aquaria. Scraping it off may or may not decrease the consumption significantly as much of it is on the rocks.