On ALK testing I was doing it wrong ...
When testing you add drops until clear (on my kit anyway), but add another and make sure there is no more change, then subtract the one that had no effect from the count. For me it changed my reading by 10 from what I was doing.
Your PH should start to become a lot more stable (providing you haven't inadvertently left the air controls on) with ALK in the 40 - 50 range, and 40 is OK which is why I mentioned adding the extra drop during the test. As a backstop my better half brings a sample to the pool store, usually most test results jive - when they don't trust yours, not theirs.
I have not tried dry acid, but use Mercuric acid (MA), which is diluted Sulphuric acid. It's not expensive and I seem to recall being told it's preferable to dry acid but I cannot recall why. Perhaps it mixes faster making a quicker ALK follow-up test more likely to be settled? Anyway, settling is important before taking your readings, you don't want to overshoot and have to drive ALK in the opposite direction - that just adds more stuff to the water. Less is better.
Also, I hate to go against any advice here since I'm new at this stuff and maybe not the sharpest tool in the shed, but it's my understanding that adding borites is something you want to do after you get things where you wish to keep them since it acts like a buffer helping to prevent change (buffers PH rise). Some say don't add it all for the same reason as in the last paragraph, less is better. Heck, got one VERY respectable gent here saying after 2 months it really is time to dump the water (as in V*E*R*Y respectable
).
(as always, long winded) Methuselah
When testing you add drops until clear (on my kit anyway), but add another and make sure there is no more change, then subtract the one that had no effect from the count. For me it changed my reading by 10 from what I was doing.
Your PH should start to become a lot more stable (providing you haven't inadvertently left the air controls on) with ALK in the 40 - 50 range, and 40 is OK which is why I mentioned adding the extra drop during the test. As a backstop my better half brings a sample to the pool store, usually most test results jive - when they don't trust yours, not theirs.
I have not tried dry acid, but use Mercuric acid (MA), which is diluted Sulphuric acid. It's not expensive and I seem to recall being told it's preferable to dry acid but I cannot recall why. Perhaps it mixes faster making a quicker ALK follow-up test more likely to be settled? Anyway, settling is important before taking your readings, you don't want to overshoot and have to drive ALK in the opposite direction - that just adds more stuff to the water. Less is better.
Also, I hate to go against any advice here since I'm new at this stuff and maybe not the sharpest tool in the shed, but it's my understanding that adding borites is something you want to do after you get things where you wish to keep them since it acts like a buffer helping to prevent change (buffers PH rise). Some say don't add it all for the same reason as in the last paragraph, less is better. Heck, got one VERY respectable gent here saying after 2 months it really is time to dump the water (as in V*E*R*Y respectable
).(as always, long winded) Methuselah
