03-05-2016, 01:38 PM
We have the typical 10,000 gallon variety water tank with the difficult-to-remove-soft-cover and were using the "place hand on steel tank" and feel for temp difference to gauge water level. We guessed that our tank was down to 1/3 and were getting worried because we have livestock and agriculture considerations for our water use.
I found this excellent web site: http://www.tank-depot.com/tanks/rainwater-calc.aspx
I calculated our roof catchment down nearly to the exact inch including eaves and gutters, even used pi for the first time since high school to calculate the area of a circle (catchment tank) so we could use a rain gauge and know, more or less, exactly how many gallons we had harvested after a rain.
Using that technique, by my calculations, our tank started overflowing after adding only about 1,500 gallons. Apparently the "place hand on steel tank" and feel for temp difference to gauge water level technique isn't very accurate. The next time I'm worried about water level I'll take a real measurement either by removing the cover and looking or using a stick or something. The hand-feeling method doesn't work.
I found this excellent web site: http://www.tank-depot.com/tanks/rainwater-calc.aspx
I calculated our roof catchment down nearly to the exact inch including eaves and gutters, even used pi for the first time since high school to calculate the area of a circle (catchment tank) so we could use a rain gauge and know, more or less, exactly how many gallons we had harvested after a rain.
Using that technique, by my calculations, our tank started overflowing after adding only about 1,500 gallons. Apparently the "place hand on steel tank" and feel for temp difference to gauge water level technique isn't very accurate. The next time I'm worried about water level I'll take a real measurement either by removing the cover and looking or using a stick or something. The hand-feeling method doesn't work.