Pond Pumps for Filters, Waterfalls and Water Courses
A Quick Pond Pump Guide
Choosing what size pond pump to run your filtration system is one of the most important factors to consider when setting up your pond. In order to establish making this decision you will need to know the following:
Size of your pond in terms of water volume.
Required flow rate based on type of filtration system used and pond size.
Size and length of hose/pipe being used.
How high your pond pump will need to pump the water.
Matching your pump to run with your filter.
Type of fish being stocked.
You should also take into consideration others factors such as waterfalls and water courses together with the width and required flow rate of these features. You may not want to end up with a trickle flowing over your supposed majestic waterfall but if you calculate incorrectly this is exactly what could happen. Otherwise you could have a gushing torrent of rapids flowing over what you perceived was going to be a gentle calming water feature.
A healthy pond with an adequate filtration system should circulate the entire volume of the pond roughly once every hour. Therefore, if your community fish pond (with no Koi) has a capacity of around 5000 litres, you need a pump with a flow rate of 5000 litres per hour (LPH), meaning that if set up correctly, all your water gets a good clean every hour.
However, if keeping koi a pond should have it's water circulated and cleaned at least 2 to 3 times every hour. This is because koi tend to excrete far more organic matter than than fish such as goldfish.