The Bambleweeny pond filter

I have my friend Bridget to thank for calling time on our green pond water.  During the second phase of lock-down, when we were permitted to meet one other person outdoors, I invited her round for a barbecue. Bridget complimented me on the excellence of my barbecued spare ribs, but not on the state of the water in my garden pond.

Algae proliferate in sunny weather, turning the pond water green. Until recently my solution has been to treat it with AlgoRem, which makes the algae floculate, then sink harmlessly to the bottom of the pond. Unfortunately, during the prolonged sun-blessed days that we enjoyed in April and May, the water was turning green again within a couple of days of being treated. The time had come to take drastic action.

The best solution appeared to be a pressurised pond filter that included a UV light to kill the algae. After trawling through several Internet sites, I settled on this one from Bradshaw's – the Pondcraft 4000 at £79.99. My plan was to connect it between our existing pump and the ornamental waterfall.

One thing that the Bradshaw site didn't mention was the size of the Pondcraft 4000, but it looks small enough, does it not?  Probably rather larger than a jam jar – say the size of a large tin of paint. Imagine my surprise, then, when a huge parcel arrived and inside it a monster of a filter, about 2 feet tall and 15 inches in diameter. Ahhh!

Fortunately, most of the filter could be buried in the earth, so from where we sit on the patio it's hardly visible. The black pipe in the foreground comes from the underwater pump.  A nice feature of this design is that the filter can be 'back-flushed' and cleaned by turning that big round knob through 90°. The dirty water then squirts out of the nozzle nearest the camera.

The next task was to wire it all up.  We already had a flexible power cable running from the kitchen larder, through the wall and a pipe under the path to the pond pump, together with two wires for the electric fence that helps ward off herons and over-inquisitive pussy cats. Now that we had a third item requiring power, the decision was made to move the whole lot into the garden, fed by a new armoured cable.

Like the new filter, this waterproof box has also been partially buried, so as not to be too much of an eyesore. According to Bradshaw's, it's proof against rain, water jets and indeed anything other than continuous submersion – "Ideal for housing power strips, cables, lights, pond pumps, filters, mower cables and more." I hope they're right, for one thing is certain; if water does get in there, not a drop will escape.

It was while helping to connect up the monster filter that I started calling it Bambleweeny. Enthusiasts for The Hitchhiker's Guide to the Galaxy will doubtless be familiar with the Bambleweeny 57 Sub-Meson Brain and appreciate the similarity. Since mine is connected to a waterfall, and not an atomic vector plotter, I think my undergarments are quite safe from the laws of indeterminacy.

Here's proof that the Bambleweeny was worth all that effort. Within a few days of connecting it up, the pond water had cleared and we could see our fish. The three posing for the camera are (from left to right) Paintpot, Nimrod and Smoky.  Nimrod is a Sarasa Comet. If you can deduce the connexion then go to the top of the class.

Eager to impress Bridget,  I showed her my Bambleweeny photos.  "Its enormous!" she remarked. "Mine is much smaller." It was then that I discovered that I could probably have managed with a small UV Clarifier, like this one.

It's actually £40 more expensive than the Pondcraft 4000, but would certainly have been much easier to install. I'm not changing it now, though. I've grown to love my hunky Bambleweeny so he stays where he is.