I watched this video as it was something that interested me. I run a full saturated calcium reactor on my 220 gallon sps tank. My ph at night can be as low as 7.65 and a high in the day of 7.95 ( all ph probes calibrated and correct). For someone in my situation what would people suggest for raising the ph? I seriously looked into dosing potassium hydroxide if it was going to help. Maybe Randy and other people can help me out here. ThanksOK, KOH and Ca(OH)2.
There is nothing special or particularly useful about potassium hydroxide. There are very few situations where I'd use it. Maybe none.
Hydroxide in any form (sodium, potassium, calcium) is a way to boost alkalinity and also pH. It has about twice the pH raising effect per unit of alk added as does sodium carbonate.
No form of hydroxide can raise pH without raising alkalinity.
If the goal is to make an alk corrective boost, then one could use bicarbonate (with very slight pH lowering), carbonate (with substantial pH raising), hydroxide (with bigger pH raising) or any mixture of them that you want (though mixing hydroxide and bicarbonate just gives carbonate).
For routine use, one of course also wants to add calcium. That can be done using any of these along with calcium chloride in a DIY or commercial two aprt or Balling, or one "one part" systems that combine calcium and alkalinity into a single entity such as calcium hydroxide, calcium acetate, or calcium formate.