How high can PH be?

[Daddi0]

My reef was running a PH of 8.2. It is in my garage which is always open and gets plenty of fresh air. Then I started dosing Kalk. As my Kalk dose started to ramp up, the PH started climbing beyond 8.5. To combat the rising PH, I started dosing vinegar. I would like to lower my vinegar dosing. So my question is how high can I let my PH go before it has ill effects on my mixed reef?
Cheers! Mark

[RobZilla04]

Increased rate of precipitation the higher pH climbs. This puts at risk all wet equipment. As far as how high before livestock becomes endangered, that's a good question.

Are you able to dose the Kalk at night when pH is lower, or perhaps dose smaller amounts more frequently?

Also you can add vinegar to the Kalk to reduce the increasing pH when dosed.

No discussion regarding effects above 8.5 and livestock, however a good read nonetheless:

http://www.reefkeeping.com/issues/2007-05/rhf/

[bertoni]

The usual guess is that anything above 8.6 is reason to be worried. Does the tank have a skimmer? Maybe it could use a bit of a tuneup? Aeration might help with this issue.

[Daddi0]

The usual guess is that anything above 8.6 is reason to be worried. Does the tank have a skimmer? Maybe it could use a bit of a tuneup? Aeration might help with this issue.
How would aeration help exactly?

[bertoni]

Aeration could bring more carbon dioxide into the system, which will lower the pH. The limewater and photosynthesis both raise pH by consuming carbon dioxide, so more aeration sometimes helps in limiting the effect.

[Daddi0]

I was under the assumption that aeration brought more air to the water and lowered co2?
I do run a skimmer and have good surface agitation on the 3 tanks that are plumbed together.
Cheers! Mark

[bertoni]

More aeration brings the water back to equilibrium with the air more rapidly. If photosynthesis and lime have depleted the carbon dioxide level, aeration will lower the pH.

[josephxsxn]

Aeration is the only thing that solved my PH issues, I highly recommend it as a first cheap attempt to solve any PH issue high or low. Typically id recommend people to perform both an indoor and outdoor aeration test to find out if they have high co2 inside the house depressing the PH, but your problem is the reverse (low co2.)

I have a single large airpump with 2 large airstones and its locked my PH into 8.2-8.3 all day long 24/7. I was also running a skimmer but it just wasn't enough to keep everything in equilibrium.