Monday 1 July 2013

I like to move it, move it

A song from the film Madegascar? Yes, and moving things around will be a major part of operations here on
the site.

Water, as previously mentioned, likes to flow downhill. Moving it uphill involves a little effort. There's 'bucket and chuck it', manual movement using mechanical means like Archimedian Screws or bucket elevators, or there are any number of ways of pumping water. Pumping seemed like a good way of doing things but the choice of pumps and methods of operation are numerous.

Looking at other resources available, I decided that I wanted to play with a low voltage system, having installed a 12v solar power/charging system down in the Toy Shed a year ago. If we're not using the system to top off vehicle batteries or charge the static battery for the inverter that runs the lights, then all that deliciously green and free energy is sat idle and going to waste. And as the sun has made an appearance this year, there's my energy source. So my power source is now either 12v DC, or inverted mains. Water and mains electricity do not make the best bed-fellows, and for temporary playing around, I'm not keen on spending a fortune on expensive gear so it's 12v DC and whatever I could find sculling around on ebay.

Enter the bilge pump! Two choices were obvious. Marine or RV/camping applications. Drilling down into the fine detail throw up two options - freshwater or wastewater. Figuring that I would be pumping from an unknown source, highly turbid and full of sediment and particulates (and the odd tadpole or pondskater here and there), I opted for a pump capable of contaminated water rather than potable water, so decided on a bilge pump for marine use.

The bilge pump is usually used with a float switch so that it can't run dry, and that is what I have done with my pump. Not likely to run dry in my applications, but a useful protection mechanism nonetheless.

The first thing I tried with the bilge pump was draining the surface water from the bottom of the Toy Shed. Although standing rainwater is pretty clean after settling, there is a lot of mud and sediment right at the bottom, so a method of mounting the pump and float switch that allowed some filtering of the sediment was needed. I had an old Curver plastic storage box sculling around, so I mounted the pump and float switch in the bottom, made up a set of flying leads that allowed me to connect to a battery, and drilled a row of 6mm holes around the base of the box, about 10mm up from the bottom. This allows water to drain in through the holes and let any sediment settle in the bottom. The pump only operates when there is 12-15mm of liquid, so this sedimentation doesn't affect the pump too much. The pump sits on a strainer base which also prevents large matter like grass or weed getting sucked up the pomp. The outflow of the pump is a 19mm bore hose outlet, so I have a length of 3/4" bore corrugated pond hose on the outlet. This will now drain the Toy Shed enough to leave just a couple of smallish puddles which soon dry up after a warm day or two.

The unit is also portable...I took it to a friends place to help with draining a pond in order to desludge it. I used the pump in the pond to suck out the water which I pumped into an old feed bag suspended in a water butt. The bag trappped all the weed, slime and sediment, allowing cleaner water to drain into the butt. The tap four inches above the bottom of the but also allowed for additional sedimentation, meaning that clean water could be returned to the pond after digging out the residual slime. Three evenings of pumping, digging, filtering and refilling left a much cleaner pond. After the job, the pump unit, butt and battery were dragged back up here in the back of Pudgy. Simples!



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