Step 1 Using pipe cutter or hacksaw, cut copper pipe into 1 length each of 900mm and 1m, and 2 lengths of 200mm. If using hacksaw, sand edges after cutting.
Step 2 Place builder’s plastic on work surface (to protect it) and sit concrete blocks on top. Wearing safety glasses and earmuffs, measure and mark centre of 1 side of block, then drill through. Repeat for remaining block.
Step 3 Turn blocks so cavity faces up and drilled holes face away from each other. Insert 1 short pipe through drilled hole, connect to copper elbow and connect to 1 long pipe.
Step 4 In a wheelbarrow, prepare concrete following pack instructions. Holding pipes still, use brickie’s trowel to carefully fill cavity with concrete, packing it firmly as you go (see Note, below). Smooth top when finished. Repeat for remaining block. Let set.
Note You can get away without soldering joints, as they aren’t under mains pressure and will be tightly held in place by surrounding concrete.
Step 5 Wet masonry drill bit and drill through centre of 1 stone. If stone is hard, clamp in a vice before drilling. Repeat for all stones. Check fit on pipes and adjust, if necessary. Set stones aside.
Step 6 Dig a hole large and deep enough to accommodate plastic tub. Roughly level base. Fill base with 30-40mm of river sand and tamp down. Position tub in hole, check level and adjust, if necessary. Backfill hole until rim of tub sits at ground level.
Step 7 Sit blocks in tub so both short pipes are facing 1 long side of tub. Cut 2 lengths of 12mm tubing and fit over short pipes, then connect ends of tubing to barbed poly T. Cut a long length of tubing and connect barbed poly T to in-line barbed tap. Cut a suitable length of tubing and connect from in-line barbed tap to pond pump. Position pump on 1 side of tub.
Tip Use Vaseline or similar to lubricate ends of connecting pieces. This will help to attach pipes, tubes and irrigation pieces of slightly different diameters.
Step 8 Wearing safety glasses and earmuffs and using angle grinder, cut reo mesh to fit comfortably over reservoir. Wrap in flyscreen fabric and secure with cable ties. Along 1 side of reo mesh, cut fabric out of 1 square (this will give you access to pump). Cut small holes in fabric where pipes will poke through and place on top of reservoir. On a separate sheet of reo mesh, cut out 1 square, cover with fabric and secure (this will cover hole).
Step 9 Fill reservoir with water. Plug in pump and turn on, adjusting flow if necessary. Stack stones on pipes and scatter decorative pebbles over grate.
Tip If too much water spills around grate, reduce water flow so it returns to reservoir instead of draining away.