I’m so confused with the volumes of my Speidel tanks. On January 6th, I started some Sauvignon Blanc from 7 frozen buckets of 100% juice from Yakima, Washington. Each bucket contains 5.25 gallons of juice. I had 7 buckets, which simple math says is 36.75 gallons. But, let’s just call it 36 gallons. Last night (January 20, 2024) I checked Brix and it was sitting at -1.5 so today, I moved the wine to 120L Speidel to settle out. I filled the Speidel, 31.7 gallons - according to conversion charts - and had prepared a carboy for the balance. I never used the carboy and the Speidel is “mostly” full. There’s no way I could have lost 4 gallons of wine. Any explanations?