I've been reefing for years now. I have a 110 gallon reef or i should say had due to some problem's .I took out all substrate and rock out got rid of old substrate rock went into a bath with some bleach took the rock out put it in the sun for 2 week's put it back in a bath with clean salt water for 2 weeks ran carbon and gfo did some water change's set my reef back up new substrate and the rock it's been a month up and running or longer mag 1500 cal 420 alk don't no i test it will say it's 7.5 so i dose BRS 2 part alk try to bring it to 9 or even 10 over night back to 6.5 light's off and i do have light's on the sump at night even i test at the same time every day and still it swing's what's up with this i have never had a problem ever with alk or keeping my reef stable any help would be great thank you.