After my alk pump malfunctioned about a month ago and mag and calcium crashed, I have since got all my parameters in check. My current issue is that for the last cpl weeks or so I'm having to scrape my glass several times a day. It's a thick reddish brownish perhaps algae? Last night I added some nitrifying bacteria to possibly help. Doing my regular weekly water changes. Livestock appears fine but something is out of whack. Appears to be just on the glass. Any suggestions