I always liked the idea of collecting rain water and using it for the garden - and for a fishroom. During the last two summers here in the Waikato we had water restrictions but Thanks to our 5000ltr tank, the veges keept growing and so did the fish.
Since the watertank is about 180cm high, it needed to go partly in the ground. So one lazy afternoon I dug a hole 2m long x 2m wide x 1m deep for the tank and fitted a retaining frame around it. The frame takes the pressure from the soil and gives you space to get to the connection in case something should ever leak.
Next on the list was a trench about 8m long and 60cm deep from the house gutter to the tank. This trench holds the pipe connecting the gutter with the tank, the coil for the heat exchanger and the new, bigger electric cabel for the fishroom, the garage and the sleep-out.
After the gutter was connected to the tank, I carried on digging the trench for the heat exchanger. All up I ended up digging a trench 30m long x 60cm deep by hand. He holds a draincoil and connects the fishroom on one side with an inlet on the other side of the garden under the trees. A wooden box with mesh covered ventilation openings keeps insects and rain out but lets air into the draincoil. Why? More about that later on :)