Just to expand on the pH issue...
Honey musts generally start out with moderately low pH to maybe even neutral. You might see anything in the 3.5-7 range. [I don't think I've seen anyone report above 7, and frankly above about 5.5 seems rare.] Honey has quite a bit of natural acidity, so plain honey musts are usually lower in pH than musts that include fruit, grain, etc. Some fruits (citrus is a good example) will bring a lot of acid too, which can sometimes lead to very low starting pH.
Yeast secretes organic acids to change its environment. This is good for yeast since below about 4.0 most bacteria have a hard time. So usually in the first one to two days of active fermentation you will see the pH drop into the 3-4 range.
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