Water storage tanks

I am completing a unique small masonry project.  This is to be a sub-surface water storage tank, made from triangular manufactured concrete block.  I will be using it as a “plunging tank” to cool off after taking a sauna.

This simple prototype uses an early version of the triangular block system described on this blog (here, here and here).  The blocks used for this tank do not utilize the interlocking key and keyway system.  I was just using up some of my older block.

This tank assembled quite easily.  It is incredibly strong, and is expected to last a very long time.  It will be filled with rainwater, as a proof-of-concept for a rainwater harvesting system.  Rain will be collected from the roof of the sauna (not yet built).  Water will be refreshed and kept from stagnating by simple replenishment from fresh precipitation.

Mortar was used in this model, although this system can also be assembled as a dry-stacked sphere.  Dry-stacking is especially easy with the key and keyway system, as described here.  A dry-stacked tank would require a bladder, or parge coat and sealant.

The use of mortar allows for the shape of the tank to be modified, if so desired.  Mortar can be applied in thicker or thinner amounts to vary the shape of the tank.  In this case, I made the sphere deeper, or elongated it almost like an egg.  This was to provide a deeper tank, for easy submersion.  It is around 8 feet deep.

I cast a pipe under the tank, so that I can run electrical wires, leading to a waterproof underwater light, at the bottom center of the tank.  This will be powered by a solar panel on the small roof of the tank.  I’m hoping it will provide an illuminated fishbowl effect.

I plan to coat the inside of the tank with inexpensive pool paint, since people will be “swimming” in it. 

The top of the tank will have a “wishing well” type roof on it.  It is important to shield the tank from sunlight, since this will encourage algae to grow.  There will also be a hinged lid on the tank to keep insects out.

I am hoping to be able to use this tank without chemicals such as chlorine or bromine.  I’ve installed a pump for circulation, as a back-up in case rain is infrequent.  This will help keep the water from stagnating, and will keep it somewhat oxygenated.

I plan to build another sphere soon, much like the water storage tank.  This other tank will be used as part of a septic system.  These tanks are inexpensive, very strong, high volume (around 1,500 gallons) and easy to install.  I will post my efforts on this blog as things move forward.

To see the tank completed, please look here.