PH Swings

are you on a reverse light schedule in your fuge? I've heard lighting your macro algae on an opposite schedule of your display tank will help maintain pH better

 

I wouldn't worry about a swing of 0.2. However, you can try things like running a reverse photocycle on a refugium or dripping kalk at night when the lights are out. However, 0.2 isn't out of line and I wouldn't try to tinker with it.

 

Yeah I agree. You mess with that balance that it swinging then you may open up a bigger can of worms. If its not broke don't fix it.

 

I would worry more about alkalinity it goes down everyday, if you dose soda ash it raises you ph along with you alkalinity, I use the stuff from bulk reef supply it's easy, and it works.

 

Word to that...pH is such an overrated parameter.  I think if everyone would worry about their Alk and Magnesium as much as their pH we would all have tanks filling over with coral.

 

Thats typical, since photosynthesis isnt taking up the carbon dioxide, it elevates at night creating carbonic acid, hence a lower pH. If you alternate your fuge it might offset it if your photosynthetic rate approaches your tanks which it usually does not. I agree, dont worry about it.