Liquid Reactor question

[Jaws]

I've been adding 4 cap fulls of Liquid Reactor every night or every other night and even though I can't seem to get my Ca and Alk up (it sits around Ca-350 and Alk-7.5), the thick brown sludgey algae that was growing on the back wall is disappearing rapidly more and more each night. Could this be because the alk is increasing and it is harder for algae to survive? I don't have a Mg test kit so I can't test to see if that's what's throwing it off. Sorry to hijack, sounds related though.