Update 11/29/2015
Over the past several months I've been having problems with low pH (mainly at night). I installed the pH probe at the same time I installed the calcium reactor, before installing the calcium reactor I was not monitoring the pH of the tank 24/7 with the Apex so Im not sure if the low pH during the night is due to the low pH effluent coming out of the reactor or if its because during the night I have the 4 wave makers in the tank go down to 30%. When the pumps run at 30% there isn't a whole lot of surface agitation so that could also be the problem. The pH drops to 7.65 thought the night and raises back up to just above 7.9, there are days were it goes up to 8.1 but that barely happens.
There are many variables as to why the pH is dropping at night and not going pass 7.95 during the day so instead of trying to narrow it down I decided to modified the air intake of my skimmer and have it draw air in from outside. I also made some changes to my water mixing station. I took out the old 30g tank I had for mixing saltwater and put in a 50 gallon glass aquarium. This will allow me to not have to measure salt every time I do a water change since I can just drop a whole bag of salt in the tank which makes 50 gallons. Now I'll be changing roughly 15% of the total water volume in my tank. I also had to redo all the plumbing in the water station so I decided to upgrade the pump to a Little Giant which I hope will pump water a little bit faster from the garage, up through the attic and down into the tank about 40 feet away.
Here you can see the 1/2" line that goes up to the attic.
Now to the skimmer air intake mod. In order to do this I needed to drill a hole on a exterior wall, lucky for me the wall to the right of my tank is an exterior wall. Since I was already going to be drilling one hole why not just drill TWO holes

. The second hole will serve as a drain. I have a manifold with 6 ports connected to a DC6000. One of the ports on the manifold will be hooked up to the drain so that during water changes I can just open a valve and pump out 50 gallons of old saltwater.
A BIG drill bit was needed for this job!

3/4" in diameter and 12" long
I missed the center of the cinder block by half an inch, I guess I got lucky because that would had made this a lot harder.
Holes sealed and plastic flange installed to cover the hole and sealant.
Let me tell you that getting both pieces of pipe behind the tank and installing the metal holders was not easy.
Skimmer air intake connector
and the drain line connected to the manifold
Top pipe is for the skimmer air intake and bottom pipe is for the drain line.
I drilled some holes in a 1/2" cap to stop any outdoor critters from crawling there way inside my skimmer
I will report back and let you guys know if the pH stays more stable now or if the problem continues. I still need to extend the drain line on the exterior so that water doesn't pour out right next to the house. Not sure what damage this will do so better be safe than sorry, thats for another day since I have to dig a trench and run some pipe underground and away from the house.