Mini Water Pumps
Mini water pumps are used when low pumping flows or pressures are desired,
typically for small-scale applications. These applications include:
- small garden fountains
- tabletop fountains
- small ponds, aquariums
- making water scenery for model railways.
Mini water pumps, as the name suggests, are quite compact - measuring on average about
6x3x5 inches (equivalent to 15x8x11 cm). A mini water pump typically delivers around 1 gallon per minute
(equivalent to 3.8 liters per minute). It is important to check specifications for individual pumps, as these
values are averages, and there can be a range.
The most common power source for this type of water pump is 12V DC. However, solar power is
becoming increasingly popular for mini water pumps. This popularity is due to the fact that for most small-scale
applications (which tend to be decorative), uninterrupted pump function is not critical.
Selection Of Mini Water Pumps
Depending on the application, either size or pump rate will be the most important factor in
selecting mini water pumps. For example, in the case of making water scenery for model railways, size will be the
most important because it is best that the pond water pump is hidden from view (e.g. housed within some other part of the
scenery). The pump rate will not be critical for water scenery because a range of water speeds will still give
similar overall effects.
On the other hand, in the case of a small pond or aquarium, the pump rate would be the most
important factor instead of size, because it is important to have sufficient flow to keep the water oxygenated.
If mini water pumps are to be used for an aquarium or small pond as opposed to purely decorative
applications, uninterrupted function is a necessity. So if a solar powered mini pump is used, it must be a model
possessing some form of backup (e.g. battery).
For small fountains, a mini water pump should be selected which will give the desired fountain
height. It is recommended to pick mini water pumps whose maximum fountain height is slightly higher than the
desired fountain height, because pumps do not typically operate at maximum height. On the other hand, it is
important not to overdo the height, because it would look odd and will also generate too much splashing over the
Routine Maintenance Of Mini Water Pumps
As with any pump, mini water pumps should be inspected and maintained. The user's manual will give the best
model-specific instructions. However, if the pump has been performing poorly, there are some things to look at
which are common to all mini water pumps. The first is to ensure the inlet is not clogged. Another is to check
the mechanical seal, gaskets and O-rings for leaks. It is also important to ensure that no air is in the system;
priming the pump will fix this (see user's manual for model-specific instructions). A worn impeller can also be
a cause of poor pump performance. The impeller is the blade which rotates in a cylinder, pushing the water
against the tubing wall and giving fast water outflow from the pump.
Mini water pumps are relatively cheap. So if the problem is something which
can’t be easily fixed, then it may be simpler to replace the pump (e.g. in the case of a difficult-to-seal
gasket or a worn impeller). However, straightforward problems can easily be fixed without replacing the pump,
such as a clogged inlet or a pump that needs re-priming, so routine inspection will pay off.