PH problem on new system stuck at 8.0

[hohmfree]

I can not seem to get the PH above 8.0
I have been running a new system since the beginning of January. It is a 120g with a large wet/dry filter (30x18x14). I am using a Dolphin 2100 for the return and have a dedictaed Blueline 55 for my MR2 skimmer. Lighting is 2 175w halides with 2 96w PC actinics. I recently bought a Marine Pinpoint PH monitor. Both it and PH test kits verify PH level at 8.0.
I have been dosing the system with Seachem reef buffer about every 2-3 days. The level goes to 8.3 then eventually drops back to 8.0.
Can overskimming cause this?
It has been 5 years since I set up a new system and do not recall having this problem in the past.
HELP!!!

 

[bertoni]

Overskimming won't drop the pH. When are you measuring pH? The pH of most tanks drops when the lights are off because photosynthesis is no longer consuming CO2.

What is the alkalinity level in the tank? Also, low pH is often caused by CO2. This article might help:

http://www.reefkeeping.com/issues/2004-09/rhf/index.php

 

[Randy Holmes-Farley]

I have been dosing the system with Seachem reef buffer about every 2-3 days. The level goes to 8.3 then eventually drops back to 8.0.

Buffers are not a good way to raise pH. The article above describes better methods (limewater and/or more aeration with fresh air).

 

[steve the plumb]

You are better off driping kalk for evaporation to raise PH.Is your tank room well ventilated?I have the same problem with stale air since I don't open my windows.If you start to add kalk water you will see a rise in ph.You can open a window to get some fresh air then you will see a differance.Depends how cold it is outside.I don't think you will leave the widow open if its freezing outside.