Hi all
I am new to the game. Bought a house with a pond. Pond holds about 32000 liters of water.
It has 2 bottom drains and a 4 chamber bio-filter holding another 10000 liters of water. It was fitted wit 2 1kw Spec pumps and a hakko air pump..
The one pump broke during November & I never got around to replace it. This pump also fed the UV light. The pond still remains clean and no problems with any algae or anything .
There are 28 koi in the pond varying in size between 30 & 60cm.
That is the background. I need to know if the pump should run 24/7. Is it necessary to have 2 pumps? The electricity bill is running away and with the new increases imminent I am starting to wonder if it is all worth while.

Hi Piet

Your water should be turned around at least ever two hours although it is better to turn it around every hour.

With one of your pumps, you will achieve the goal, especially because of the size of your pond and the amount of fish. The larger the pond the less turnaround needed.

Your other option would be to replace the two pumps with a Speck Eco Touch with it's three different settings. In winter your can run the lowest or middle setting and in summer, the high setting, delivering 32 000 liters.

If you are worried about electricity and still wish to have good turnover, you can add a low wattage low pressure pump to increase flow and to assist your one high pressure pump. For instance, the PC 18 000 delivering 18 000 liters @ 90 watts. (Please note most use more that the specs)

Your pump/s should run 24/7 or else bad bacteria will grow and take over, causing all kinds of problems.

Your pond is clearly matured, so you can do away with the UV. Easy to put back later if needed.