Concrete and mortar have been favored by pond and fountain builders since the roman empire and the formula has changed little in the past 2000 years.
Building a koi pond with concrete block.
Select a level location for your pond.
How to build ponds with concrete blocks 1.
Measure half of the diameter of your pond on a piece of garden twine and cut the twine to this distance.
Once the area is clean use a shovel or front end loader to dig out the pond giving the sides a slope of 45 degrees.
As this pond was designed to be only 3ft 6 deep and to hold around 1 700 gallons of water the walls were constructed of 100mm dense concrete blocks on edge.
By using the hydraulic rebar cutter the rods could be cut to specific lengths.
To build a concrete pond start by outlining the pond with marking paint or rope and clear the area of any rocks or debris.
During the pour the footers were poured first then the slab of the pond.
The choice of this size of block may come as a surprise because we so often see ponds constructed using 9 hollow blocks backfilled with concrete and reinforced with steel rods.
Remove the sod if necessary from.
With the pond box retaining walls completed you re now ready to place the hydroclean pond skimmer.
The rebar was placed on top of rebar chairs rebar blocks could be used as well to keep the rods in the center of the concrete pad during the pour.
3 size rebar 375 was used in the slab.