There are many designs of fountain ranging from a simple vertical jet to sophisticated dynamic sculptures of which running water forms an integral part. High jet fountains are inclined to lose lots of water in a small pond especially on a windy day. My own pond suffers more from losses through the liner.
Here are a couple of striking fountains which are at the Keukenhof gardens. I hope sometime to make my own version of the shimmering bowl of water fountain shown below.
Both of these fountains use a plate to deflect a thin disc of water radially away from the pipe which feeds it. The single bowl forms a large bubble trapping air inside and gives a very pleasing effect. The multiple headed version is very much like a dandelion clock and needs a very large pond.
These are a couple of novel fountains in the garden of the International Olympic Museum at Laussanne in Switzerland. The man with umbrella (by Jean-Michel Folon) is a variant on the basic horizontal disk of water fountain. The other with a short throw and an overflowing cascade is more suited to a smaller garden.
Various companies offer self powered solar fountains and I have always been rather skeptical of the claims made for them. Not least because the UK is not all that sunny. However, I recently acquired a surplus (presumably bankrupt stock) solar powered pump designed for one of these fountains to irrigate my greenhouse.
The pump is small self contained submersible and made of orange plastic. It looks rather small and is rated at around 8 litres/minute at no load and up to 17 foot head of water at no flow. I bought the device on spec for about £20 in the hope that it could be adapted to irrigate my greenhouse which has lots of water stored in a deep concrete reservoir.
I tested the unit in the kitchen sink unsure how well the thing would work using a lead acid 12v accumulator for power. I was somewhat surprised that a quick splash on the terminals was enough to send a pulse of water crashing into the ceiling which made me a little unpopular - at least it was clean water. The second test was done outside in the pond to see how well a fountain using one of these pumps would behave if given a decent power source.
The results were much more impressive than I was expecting. The basic pump could throw a modest sized jet of water around 6-8 feet into the air under the most favourable conditions. I will revise my opinion of the potential for having a decent solar fountain upwards. I used to think they were a joke having previously seen rather feeble things struggling to pump a very small volume of water I wasn't prepared for what happened.
These pumps might be fast enough to be able to do dancing water fountains which shoot short pulses of water into the air in regular patterns. I expect such intermittent use might cause very rapid wear though.
The limitation in commercial solar fountain designs is inadequate solar panel size. Solar panels are intrinsically expensive costing around $4 per watt and a fountain pump will need 10-20W to run well. The solar pump that I used for this project came from Bull Electrical a surplus dealer in the UK. The main problem in building your own is making sure all the electrical connections are truely weatherproof and stay that way in a hostile outdoor environment.
The conclusion of my experiments was that a decent solar powered fountain using this pump requires a power source which can deliver about 1.5A continuously at 12v. I cannot yet assess the pumps long term reliability as I have only had the setup running for a few weeks but it is a lot easier than lugging a watering can up and down the greenhouse. It only needs to run for about half an hour daily to provide my greenhouse plants with water. The pump lasted three seasons before it wore out. I expect it would last longer if it was run in a less demanding environment.
The control of the pump was by a small PIC based daily timer to give two bursts of water for 1-30 minutes in the early morning and late afternoon.
|Unloaded - pumping air||0.3A||4W||N/A|
|8v supply - pumping water||0.9A||7W||0.5m (approx 2')|
|12v supply - pumping water||1.6A||20W||1.2m (approx 4')|
|14v supply - pumping water||2.0A||28W||2.0m (approx 7')|
|Irrigation - air in pipes||1.7A||22W||N/A|
|Irrigation - pumping water||1.3||15W||1.0m (approx 3')|
The latest problem which is peculiar to my setup is that the mosquito larvae in the water tank tend to get sucked through the filter mesh and then jam up the jets in the irrigation system. I intend to use a finer filter mesh. The fittings designed for greenhouse spray irrigation would otherwise be ideally suited to low flow home fountains.