What type of pump should I use?

[grasslizard]

I am constructing a small splash pool in my garden. It is rectangular, made of concrete and measures 16' x 8' x 4' which gives a volume of approx 3830 US gallons, or about 14000 litres.

Due to the slope in the garden, the pump is located below the water level, just below the bottom of the pool, so I guess it is a bit like an above ground pool arrangement.

I am struggling to decide on what size and type of pump I need. I would like a pump which is small enough to run for a long time each day. The pool shops are trying to sell me 0.75 or 1hp pumps (they have no smaller here). I was thinking about using a combined pump / filter designed for above ground pools, I have seen one here rated at 0.2kW which seems to match the pumping requirements of the pool, but does seem a bit small compared to the others. The pool is in the tropics and will be used year round if that makes any difference.

I would appreciate any advice you could give me. Thanks very much!

[CGPoolman]

Hi Grasslizard,

For the size pool you are describing, I would go with 1HP above ground pool pump with a smaller sand filter. You can probably even go with e 3/4HP pump and be OK. Hayward makes the Power Flo pump which is pretty popular. It is a single speed - runs quiet and is very easy to repair if you ever have any problems. A 1HP (averages 1.1kw) could easily turn the water over twice a day running only a few hours, resulting in less run time and less electric. The smaller pump would probably need to run all day long to do the same amount of work, resulting in a lot more wear and tear on the pump, and more electric used.

You can usually buy a "skid pack" which has the pump and filter together on a plastic base. All you have to do is connect your pools plumbing and plug the pump in and you're ready to go. You can purchase these online but once you pay for shipping it is probably less expensive to buy it locally.

-CG

[grasslizard]

Thanks CG,

Your advice is similar to the what the local pool shop has said, and it makes sense in terms of pump usage.

I have read elsewhere online though that I should use a pump which is small enough to run 8 hours per day in order to ensure that the water is always moving. For this I would need a very small pump to keep the electric bills down.

Do you think that running the pump for 2-3 hours is enough?

[CGPoolman]

In my opinion - I still would not go with any less than a 3/4HP. If anything, I would go with a 2 speed pump. Run it on high for a few hours to filter, then drop it to low speed for a few hours to circulate.

-CG