pH dropping -hello winter

[asylumdown]

According to my Apex, the pH in my tank hovers between 2.4 and 2.8. Apparently the absence of a probe is quite acidic...

The one thing I would mention about reef buffer is to be careful about how you interpret your alkalinity readings after you use it. Reef buffer contains a significant amount of borate, which contributes to total alkalinity. If your'e using a single reagent titration test kit for carbonate (i.e., you add a single coloured reagent directly to your water until there is a colour change) to measure your dKH, you're measuring total alkalinity.

I ran in to a problem when I was a newb where I was adding too much reef buffer and not enough carbonate/bicarbonate. My dKH was consistently reading in the 8-9 range, but then all the tips of my corals started burning, then whole colonies started practically self immolating. I bought the Seachem test kit that allows you to test for both borate and total alkalinity and discovered that my carbonate alkalinity as measured in dKH was down around 4.5 or something ridiculous.