So, filter pumps, which one? What's the difference between this and a fountain pump? Why are there so many types? Filter pumps differ from fountain pumps by the size of particle debris they will handle, unlike fountain pumps this type of pump will handle large (well, large for pond debris) particles of up to 12mm, that's roughly the size of your little finger! They are normally physically bigger than their fountain pump counterparts, will come with very few fittings - normally just a hose tail or two.
Typically a filter pump will move larger volumes of water, but generally under less pressure than its fountain pump cousin.
This is normally due to the fact that a filter pump will use larger hose sizes, which put less back pressure on the pump.
Right, so you now know the difference, so how do you choose the right size? There two pieces of information you would normally need, (occasionally three - dependent upon the size of the installation).
These two things are: 1.
How high you are lifting the water 2.
How much water you need.
3.
Is pipe length, but isn't always required - a general rule would be under 5m and it's not a major concern.
- How high?? This is very important and often calculated incorrectly.
e.
filter box, top f waterfall etc.
- How much?? Again, critical if you are going to select the correct pump.
This 'flow rate' is all based on specific requirements i.
e.
is it to produce a certain width waterfall, is it to run a filter etc.
If it's for a waterfall then you are looking at approx.
100 l/h per for every 1cm of waterfall width, for a faster flow (more torrent than gentle trickle) then you need to at least double that.
If it's for a filtration system then you need to know the pond capacity, and dependent upon fish stock (goldfish / Koi) and filter system being used.
For a Goldfish pond you will normally need to circulate half the pond capacity (2000 litre pond = 1000 litre/hr), and for a Koi pond you would circulate the entire pond capacity every hour (2000 litre pond = 2000 litre/hr).
- Pipework.
If you intend to use more than 5m of pipe then you need to consider frictional loss in the pipe.
Please see link for how to calculate this.
Read across the bottom for flow, when you get to your required flow read up until you meet a line that is at least at your required height, and that's your pump.
What make should I go for? There are plenty of options when it comes to pumps in this category, with sizes and prices varying massively.
There are a few key factors that you should consider before parting with your hard earned money.
Running costs - this is becoming more and more important with rising energy bills and when you consider that if this pump is going to be used as part of a filtration system then it's going to be running 24hrs a day, 365 days a year.
There are more and more 'Eco' pumps on the market - don't be fooled into thinking that just because a marketing department has decreed that the new pump is an "Eco" that it's going to be the cheapest to run, always check the wattages from brand to brand.
Oase are generally the cheapest submersible solids handling pumps to run, they were one of the first to develop an Eco motor and currently offer the cheapest pumps in this category in the form of the Aquamax Eco Premiums.
These pumps also have fantastic 5 year guarantees as well as the largest strainer surface area and largest solids handling capacity of any pump in the category.
Oase also offer a cheaper version of the Aquamax - the Start range, in limited sizes of 3500, 5500 and 8500.
Velda and Hozelock also offer good quality, low running cost pumps with 5 and 3 year guarantee's respectively.
Both of these suppliers offer a good range of sizes.
At the entry level price there is Bermuda who offer their own, slightly more basic version of the above pumps at a lower price.