Looking To Pick Your Skilled Brains Answered
Advice on best how to make a piezometer out of readily available hardware store parts without use of any power tools and access to only a very few hand tools. Basically a piezometer is a clear, straight plastic tube that you attach to the outside of (in my case) a plastic 250 Liter rain barrel (about 1.5 feet diameter, 4 feet high) from top to bottom. The top is exposed to the open air, while the bottom feeds into the bottom of the barrel (by going through the side very close to the bottom). It needs to have a diameter of about 1/2 inch, be very solid, straight and secure, and a 'water level mark' must be etchable in it somehow to indicate the normal level of water inside the barrel when the barrel is full (full means a few inches before the absolute rim of the barrel). The barrel is filled with gravel at the bottom, sand on top, and enough room for a 12" waterhead above the sand. I'm using it as a slow sand filter (SSF). The idea is that the pressure of water at the bottom of the barrel fills the tube up to the watermark against the action of the atmospheric pressure forcing the level in the tube down below the watermark. When the level of the water in the tube is about 15 inches below the water mark, it means the water pressure at the bottom of the barrel has decreased to the point where the sand in it needs to be cleaned (no water getting through). Any ideas will be greatly rewarded in the afterlife. Thanks!