Lon and I have been fixing an error that I made with the height of the two connected tanks.
Pic 1 (above) shows the error. Water went into tank 1 (left) and was passed to tank 2 (right) by a pipe going near the base of each. The overflow on tank 2 was far lower than that on tank 1. This meant that it was the highest level the water would ever get to in both tanks, resulting in wasted space above that level in tank 1.
The blue coloured area shows how much we were losing! 130 litres might not sound like much but it’s the same amount as a red wheelie bin holds.
The second pic is the new positioning. It gives us around 130 litres of extra storage capacity for water, as well as more storage space underneath.
There was one bug in the new design. Tank 1 doesn’t have a second tap fitting or it would have been easier to reverse the two tanks and adjust the height of one only. Now there is an area of about 60 litres that sits below the height of the inlet of tank 2. Pic 3 shows this, as well as my solution.
The solution: I didn’t have the gear to make and solder in a new fitting, so I added a recycled ball valve to the connecting pipe. Now we can access all of the water in both tanks. It also provides better access to rainwater so that we’re not as tempted to use tap water.
Our future proofing continues. I’m putting my money on a 2.7 °C temperature rise and less rain but heavier downpours (a warmer atmosphere holds more moisture but even it lets go…), so catching water when it rains and preventing runoff are going to be techniques crucial to good gardening.