Whoa! That's a big difference between the "recommended" charts.

The chart that EWest posted stated the HIGHEST ratio test was 0.5 grams of Alum with a 5 gallon bucket, which would be 0.1 grams of Alum with a 1 gallon bucket.

The chart David U posted above stated the LOWEST ratio test was 1 tablespoon of Alum with a 1 gallon bucket.

I had purchased a digital scale which will measure down to 1/100th of a gram (0.00). This allowed me to perform my test in a 1 gallon container instead of 5 gallon buckets.

I can tell you that 1/8th of a TEASPOON of Alum weights around 0.83 grams, while 1 TBSP (tablespoon) weights 24 grams!

BIG DIFFERENCE!!!!

Why are these so far off from each other????

I can also tell you that I had a pH level of 7.8 and using 1 gram of Alum in a 1 gallon bucket crashed the pH to 6.2.