Sight glass markings

[Dan65]

I will be soon marking my gallon levels on my sight glass and thought it might be more accurate to weigh the keg with water inside it instead of pouring in a milk jug(whatever container you choose) of water in.
I then saw that the weight of water depends mostly on the water temperature.
"The density of water varies from 0.9991026 g/mL at 15 C(59F) to 0.9956502
g/mL at 30 C(86F) according to the NCSU site, so the figure I have
calculated will vary from 8.337915 to 8.309104 lb.gal over this
temperature range. You can see why figures of 8.3 and 8.4 are given:
to be more accurate requires knowledge of the temperature." http://mathforum.org/library/drmath/view/56355.html

This post is just a thought to obtain a more accurate measurement, not to stir up those with OCD

 

[dmcman73]

Don't look to much into that, this isn't rocket science where adding slightly more water to a mash won't cause an explosion.

Simple way to do it, add a gallon, see where it come up on the glass. And a second gallon, mark it then measure the distance from the first gallon to the second gallon mark. Just for sanity check, add a third gallon, mark it and measure the distance from the second gallon mark to the third. If the distance matches between the two measurements, then no need to add any more water. Using a ruler, measure out each gallon mark on the sight glass with the measurements you took.

 

[Spartan1979]

When I did mine, I weighed out a gallon of water in a jug. I marked the level of the water in the jug and just kept filling to that point. I figured it was close enough.

 

[Sconnie12]

The .03gal difference will ruin your beer, watch out!!

Relax, have a home brew!