If you wanna get a nice little bump in pH just run a RO line from your skimmer intake to outside air. It's that simple and may be all you need.
If you want perfect pH 8.2-8.4 and you're not getting there with the skimmer intake, then you can dose Kalk. The excess CO2 build up in our houses combined with Carbonic Acid will typically prevent our tanks from reaching the desired pH of 8.3-8.4. There are some exceptions, but not many.
When you dose Calcium Hydroxide aka "Kalk" the Hydroxide combines with the Carbon Dioxide (CO2) to form Bicarbonate Alkalinity this significantly reduces the free CO2 in the water and also reduces the formation of Carbonic Acid and results in a higher pH. If you dose Kalk and run the skimmer intake on outside air you will have a pH as high as you wish. If it goes too high, you can simply reduce your Kalk dose or unplug your intake line.
The only part that is confusing from most reefers is how exactly to run Kalk. Well, there's several ways and one of the easiest is in your topoff. It can also be one of the most dangerous. The reason why I stopped running in my topoff was due to 3 reasons:
1. Safety- The topoff may get stuck on. (Although you could gravity feed it)
3. Hard on topoff pump. (Will clog it over time)
2. Control- The inability to fine tune the dose and have better control. (There will be different fluctuations of topoff water from summer to winter).
You can also drip it and count the drip rate, but there are more variables to calculate such as "drop factor" (size of the tubing used). Or you can dose it which is currently my preferred way. It's easy to fine tune. A fully saturated solution is fairly weak. I like the convince of being able to change the dose if needed on my phone app with GHL. Although since it is very weak, I don't have too. I dose ESV on top of the Kalk to maintain my parameters. I dose 300mL daily of Kalk and let ESV take it form there.
You can start at 1 tsp per 5 gallons of RO water or go full force into a fully saturated solution with a max dose of 2 tsp per gallon depending on your demand. Either way, you will appreciate faster growth and corals that lay down a base faster.
I use a little over a 6000mL container. Last for more than 2 weeks before I need to fill it again.