I checked my fresh water capacity

[kpm]

Today I did a little experiment. First I emptied the fresh water tank on my 25 FB, which has a published fresh water capacity of 39 gallons. The 6 gallon water heater remained full.

Then I filled the fresh water tank by hand 6 gallons at a time. At 36 gallons, it measured 94%; my SeeLevel appears to be reasonably well calibrated. The outside overflow started producing at 48 gallons, 9 gallons above published capacity. In the future I will treat my fresh water tank as 48 gallons when periodically sanitizing with bleach, since I generally fill to overflowing.

[AstroBruce]

I did the same test. I could only get 35 gallons.

Bruce

[kpm]

Ha, based on your comment, I redid my experiment. The first time I over counted by 6 gallons, so here are the revised measurements.

gallons - seelevel%
6 - 19%
12 - 38%
18 - 50%
24 - 75%
30 - 94%
36 - 100%
42 - 100 % overflow

The fill hole overflows at 42 gallons. The Seelevel II reads 94% at only 30 gallons, so it is significantly over reporting the level.

[brick1]

Ha! I just did a gallon-by-gallon test of my grey water tank. Only 25 gallons and it showed 100% full!

[kpm]

Good to know. You have the 39 gallon gray tank yes?