Koi Pond Pump Selection ::
Selecting the correct type and size of Koi pond pump is a crucial decision in ensuring your Koi have a healthy clean environment and you have the minimum of problems with maintenance and health problems. Along with the filter, the pond pump is the most important piece of equipment needed to run a successful Koi pond. There is a fantastic selection of pond pumps available and the choice can be confusing for the first time Koi keeper.
Pond Water Capacity:
Fortunately there are several guidelines when it comes to choosing pond pumps that can help you make the correct decision first time. First, it will pay you to work out the water capacity of your pond carefully. Decide what restrictions (if any) that there will be to water flow, and from this calculate the capacity of the pump required to provide the correct water flow around your pond or water feature.
Water capacity = length x depth x width x 6.25 = Gallons, all measurements in feet. To convert to Litres multiply the gallons x 4.54. The usual rule of thumb is to turn over the whole of your pond water through the filter system every one - two hours. However as with most rules of thumb there are exceptions. Most people with very large ponds of 5000 gallons (22,700L) or over, tend to circulate their pond water around every two -three hours. This avoids the cost of running extremely large pond pumps.
Water Flow Rate:
When selecting pond pumps it is important to bear in mind the effects that lifting water to a height and moving it through a length of piping will have on the flow rate of the water. The pump must be chosen on the basis of the amount of water flow it will provide at the point where the water goes into the filter system, or returns to the pond, not the maximum flow rate. Pond pumps are typically rated using their maximum flow rate, coming straight out of the pump with no resistance. However the actual flow rate coming out of the end of a long pipe run will probably be significantly less.
For example, an Oase Aquamax 12000 pump produces 2600 gallons / hour (12000L) measured directly from the pump, but at a head (height) of 3 feet (1M) it has dropped to 2100 gallons (9,600L) and at 6 feet it has dropped to 1580 gallons (7200L). Most pond pumps will show a range of flow rates for different heights, so it is a simple matter of choosing one that will give you the flow rate you need at the height you are pumping up to. Allow about 10% extra on top of that to account for the slowing of the pump as it ages.
Types Of Pond Pumps:
Your next decision might have to be whether to choose a submersible pump, or an external pump and this choice will most certainly be influenced by pond size. External pumps normally turnover large amounts of water, making them inappropriate for small ponds, but very useful for large Koi ponds. If your pond is smaller than 13,500 litres (approx' 3000 Gallons) capacity, then you may have toopt for a submersible pump, and it is better if you know a little about these beforehand. With a small pond you must be extra careful about your choice of pump for you may be operating under conditions that are marginal for Koi.
Look through the pump adverts to see what the rated capacities, and features, of the various unitsare and before you make your purchase, talk to other hobbyists who may have some good advice to give you. A handy source of information on recommended pump prices and performance are the Buyer's Guides published in the Koi Magazines each month. Oase do make a submersible pump that may also be run as an external pump, and this is certainly worth consideration.
You should also consider that Koi keeping is a hobby that grows on you, and when the bug bites, then you always want just a little bit more from it. A pond of 4500 litres could a year hence, prove to be too small and you will be rebuilding it. Some Koi keepers progress through ponds one to five ,each one bigger and grander than the last one. A lot of money is wasted in this manner and it is always best to go for the biggest pond that you can envisage - right at the start.
Submersible Pumps:
Your next decision might have to be whether to choose a submersible pump, or an external pump and this choice will most certainly be influenced by pond size. External pumps normally turnover large amounts of water, making them inappropriate for small ponds, but very useful for large Koi ponds.
If your pond is smaller than 13,500 litres (approx' 3000 Gallons) capacity, then you may have toopt for a submersible pump, and it is better if you know a little about these beforehand. With a small pond you must be extra careful about your choice of pump for you may be operating under conditions that are marginal for Koi.
Look through the pump adverts to see what the rated capacities, and features, of the various unitsare and before you make your purchase, talk to other hobbyists who may have some good advice to give you. A handy source of information on recommended pump prices and performance are the Buyer's Guides published in the Koi Magazines each month. Oase do make a submersible pump that may also be run as an external pump, and this is certainly worth consideration.
You should also consider that Koi keeping is a hobby that grows on you, and when the bug bites, then you always want just a little bit more from it. A pond of 4500 litres could a year hence, prove to be too small and you will be rebuilding it. Some Koi keepers progress through ponds one to five ,each one bigger and grander than the last one. A lot of money is wasted in this manner and it is always best to go for the biggest pond that you can envisage - right at the start.
External Pumps:
With external pumps, the choice always seemed to be easier, but there are a lot more designs arriving now, and the choice is getting harder. The Mini Dolphin pumps are extremely powerful, and if you want delivery capacity, and reliability, at an affordable cost, then they are one of the most suitable choices.
Sequence pond pumps do have lower wattage pumps in their range, and these give lower running costs. However the lower wattage does mean the Sequence pumps produce less pressure and may not be suitable for applications where water needs to be pumped up more than 5 - 6 feet vertically. They are also not the first choice for long pipe runs with large numbers of bends.
General Advice:
General advice for running high powered submersible pumps: 1) Do not to run them too deep in the water. This puts a lot of pressure onto the shaft's water seal and can cause premature failure. 2) Never unduly restrict the outlet of a high powered submersible pump, this will considerably shorten its life. 3) Never carry a submersible pump by its electrical lead, This can damage the lead and damage the water sealing.
General advice for running external pumps: 1)Most external pumps are not self priming (if run above the water surface, will not suck up water without first being primed) and therefore need to be run in a dry chamber that is below the pond water level. 2)Make sure that pumping chambers are well ventilated, as overheating will reduce the life of pumps. 3)Make sure that the filter baskets (if fitted) are kept clean as a blocked basket can cause cavitation and damage the impeller. It can also cause overheating of the pump. 4)Make sure that they are protected from water splashing and rain external pond pumps are not weatherproof.
Above all, whatever type of pump that you use, make sure that all of the pond electric circuits are protected by an RCD. This device will detect electrical leakage and protect you from fatal electric shock if a fault should develop in any of your equipment.
To View a Selection of Pond Pumps Click Here
Return To Top Of Page
