7 months in and I'm starting to get quite a few small spots of coralline growing. It looks like it's coming in under the GHA in places (I'm guessing it's GHA, it's been on the back of the tank for quite a while). Will scraping the GHA off the back have any effect on helping the coralline grow more quickly? If it grows underneath the GHA like this, I'm guessing the coralline will kill the GHA off as it spreads. Is this correct?