I'm not sure I'd agree with the fact that PH meters are notorious for being inaccurate. I'd say they are one of the more accurate measurements we can do at a cheap price. Most instruments calibrate easily and hold the calibration pretty well.
I do agree 100% with the aim being to adjust your alkalinity or KH with PH being secondary. PH and KH are different beasts but are related so neither can be "ignored". The best way I can suggest is to "boost" your KH and Calcium in a way most suitable to getting you to the "ideal" PH.
Idealy you want your PH in the 8.0-8.2 range but not at the expense of extra high or low alk/calcium levels. Knowing these 3 values you can decide the best way to boost alk & calcium short term. For example if the PH is on the low side then the best way to boost alk & calcium is with a limewater drip as opposed to 2 part or using a calcium reactor (which will lower your PH).
PH is an important measurement and shouldn't be "skipped" relying on a KH test as they are not the same thing. It's important to know your KH in ORDER to figure out the best way of boosting or raising your KH so that PH will rise or fall.
For example to raise both KH and PH you slowly add sodium carbonate to the aquarium water. The main reason why this is done is simple: carbonates raise the pH and the dKH, not just the dKH as bicarbonates do. At first, when you add this compound the pH will go up and will do so rather quickly (sodium carbonate raises the pH). As sodium carbonate reacts with acids of various kinds that are dissolved in the water, it becomes gradually neutralized (and so do the acids), with the result that the pH drops again. The more acids (or acidity) are present in the water, the longer this up and down swing of the pH will continue. Before any significant and stable changes occur, all, or just about all, acids need to be neutralized and eliminated from your aquarium water. This is done by continuing to add small amounts of sodium carbonate. Notice that I stated small amounts. We cannot add large amounts at once as the pH swings that this would bring about would be too stressful for the animals. Sodium carbonate is very high in pH and even small amounts have a large impact on the pH just about immediately after adding it to the water. So, if after adding this compound a few times you do not see the pH rising, what this really means is that acidity is still present in the water and that it causes the pH to drop again, as the effect of the sodium carbonate is eliminated or in other words chemically neutralized. Of course, when this happens, the amount of acidity is lowered as well. As long as this rise and fall continues, you have not neutralized all the acids yet and you need to continue to add sodium carbonate. You do so until the pH rise continues but the drop starts to become smaller, or disappears (at which time you know you have neutralized the acids).
PH is a critical parameter of reef keeping and that IS WHY experienced reefers talk about it. You do see less and less talk about it in general because more and more people are using balanced additives and such which helps. Our reef salt mixed are better and these things all help but it's not an excuse not to check it or to take the proper procedures to correct it.
Knowing what PH really is and how it relates to KH, calcium, magnesium, borate and CO2 levels in the water makes adjusting it not that complex. It's not a black science or some mystery. It's not just adjusted by way of calcium or neilson reactors although that is the way many "try" to balance it which is only a bandaid. I mean bandaid in the sense that as soon as the reactor is turned off or stopped the PH returns to the "normal" level which may not be in the "ideal" range.
I'm not trying to pick on you aurora but if you understand the true mechanics of PH and what it represents then you would be testing for it. How do you know the proper way to boost your alk if you don't test properly? Simply put you don't. You may be lucky and just naturally fall in the right range but it's not a good idea to give the impression that it's not important and that KH/alk is all that needs to be measured. I view this as saying you never need to check your calcium if you know your KH levels. Hell I think you could probably get by without testing calcium and relying only on your KH levels if you use a good 2 part dose but I still wouldn't recommend no one test for it.
PH is a tricky beast for many people as they think it's just some "buffering" mechanism that is fed from the alkalinity level of the water and it's not so.
