How To Compare Costs to Make the Right Pump Choice Every Time

Beware low price but High Cost. Don't be fooled by what appear to be low price pond pumps

In general you must never make an economic choice of pump based only on the purchase price. The reason is that running costs normally exceed by a significant margin the actual purchase price. In addition there are alternative ways to install pond pumps to reduce total operating cost. Let's demonstrate this using examples of pump advertised online by the leading UK supplier Pond Pumps Direct.

Pump Running Costs Example

On a previous page we worked out the specification for a waterfall pump. Here's the summary ...

"In our case we then need a pump that will deliver at least 1,800 litres at 1.2 metres head. This is the information you need to pick the right pump ..."

These 2 pumps would both meet the requirements and cost about £80 ... however look at the power consumption figures

• Hozelock Cascade 4000 ... Watts consumed 40

• Blagdon Amphibious 3500 ... Watts consumed 76

Here's the calculation for the annual running cost based upon the cost of a single kWhr of electricity beng 10 pence

• Hozelock cost ... 40 x 24 x 365/1000 x 0.10 = £35.04

• Hozelock cost ... 76 x 24 x 365/1000 x 0.10 = £66.58

Over the 5 year life of the pump you would pay out almost £158 more if you bought the Blagdon pump.

So never just compare prices ... check the Watts and do a quick calculation. To get from Watts to £ per year multiply the Watts figure by 0.9 as a simple approximation. In other word 50 Watts will cost about £45 per year, 80 Watts about £72 and so on.

If the pump box does not give a Watts figure be careful ... maybe the supplier is hiding a high cost factor. If there's no Watts but you see an Amps figure convert the Amps to Watts by multiplying the Amps by 200 for a comparitive annual running cost figure. If the Amp reading is 0.3 then the annual power cost would be about £60.

This calculation becomes even more important as you start to consider large flow and higher pressures as you would encounter in larger waterfall installations like the one in the picture. It was built by my friend Peter May who lives in Somerset and is a talented landscaper and artist and author who specializes in water gardening. See some of his sketch plans here.

Pond Keeping Units

Now we've started to talk litres you might find this table below useful. It helps to translate one set of units to another quite easily.

Example ... 1 cu.m per minute is the same as 1,000 litres per minute or 35.32 cu.ft per min or 220 imperial gallons per minute.

Factors to be aware of with all pumps. This is a good page to read before you buy any pump.

I have created 12 different pond calculators and these are available free at my other site Perfect Pond Keeping One of the calculators allows you to accurately specify any pond pump even taking pipe friction losses into account. I would suggest you get these Excel calculators and play around with them.