There are two terrific times to give your pond a good, thorough cleaning. One is in Spring and the other is in Fall after the leaves have already fallen. It’s not a task to be taken lightly. It’s wet. It’s dirty. The muck stinks and the bottom of the pond is slippery. Performing a major pond cleaning requires courage to start the ball rolling and a little muscle to get it done.

It’s a dirty job but someone has to do it! If you are that lucky person it’s time to slap on your rubber boots, roll up your sleeves and arm yourself with the right tools. Here’s what you’ll need to make the job easier:

Rubber gloves and boots
A strong wet-vac or shop-vac
A hose with spray nozzle
A temporary holding tank for fish
Strong submersible pump with 2” hose
Net to catch the fish
Aerator for holding tank
Gardening scissors or snips
De-Chlorinator (if using city or county water)
Set Up the Holding Tank

Use a hard plastic container that’s big enough to hold all the fish in your pond for a couple of hours. Most folks would use one that is 150 to 300 gallons. Locate the tank in an area that is shady and cool. Set up an aeration unit or have another pump circulating the water to create splash. Pump the water from your pond into the holding tank until about a foot from the edge of the container. (You wouldn’t want your fish to jump out during this time of stress).

Clean the Filter

Clean all filter material other than bead filters by pulling the material out and pressure washing it with the hose. Filter media comes in many forms. It could be lava rocks in the waterfall, filter pads in an outside-the-pond filter or material used to filter the water before it is sucked into a submersible pump. Regardless of what type it is, you should take the filter apart, clean it and replace any material that is worn out and shredded.

Power Clean the Bead Filter

If you have a ProBead biofilter you should take the opportunity to perform a power backwash. This can be done by opening the ball valve at the drain located at the base of the filter while performing a regular backwash. Let this run for a couple of minutes then close the valve.

Transfer Fish to Holding Tank

The trick to this is to drain as much water out of the pond as you can so the fish have nowhere to run. Using your net (and a bucket of pond water) transfer all the fish from the pond to the holding tank. Cover the tank to prevent fish from jumping out.

Completely Drain the Pond

This can easily be done if you have a ProBead biofilter by simply turning the valve to the DRAIN position. If using a submerged pump with flex hose you can re-route the hose to drain outside the pond instead of re-circulating the water.

Turn Off the System

Common-sense dictates that if there is no water in the pond the pump should be disengaged.

Remove the Plants

Remove all the plants from the bottom of the pond. Transfer waterlilies or others that wilt easily without water to the temporary holding tank.

Pressure Clean the Rocks

Thoroughly clean the stream, waterfall and rocks that surround the pond by using the pressure spray nozzle on the hose. You may have to pull some string algae off the rocks by hand. Allow the muck that comes out from between the rocks to flush down to the bottom of the pond.

If the bottom of your pond is lined with rocks our sympathies go out to you. It’s next to impossible to clean out all the muck that falls between them. Now would be a wonderful time to remove them! (Refer to our article titled, “Turn Your Pond Into a Cess Pool — In One Easy Lesson” from the Clear Water Edition of What’s Up, Doc?).

Vacuum Out the Muck

A wet-vac or shop-vac is something a pond owner should never be without. With the wet-vac suck out all the muck that has washed down from the top of the waterfall, etc. and all the fine dirt that has, throughout the season, settled to the bottom of the pond. Spray the sides of the pond down but do not scrub them and use your wet-vac to suck up all that falls down.

Clean Up the Plants

Remove by hand or gentle spray from a hose any string algae that may be clinging to the plants. Trim off dead or dying leaves and spent blossoms. Fertilize the plants if “in season”. Place the plants back to their original positions.

Refill the Pond

Start refilling the pond. While you’re doing this fill a portion of the holding tank with new water (don’t forget to de-chlor). Pump out a little of the water then fill a portion again. Do this several times so that the temperature of the water gradually decreases/increases to the temperature of the new pond water.

Clear Out the Baskets

Empty the contents from all baskets on skimmers and outside pumps.

Replace the Fish

De-chlor if necessary and transfer the fish back to the pond. Again, it’s easier if you drain most of the water out of the holding tank before trying to catch the fish.

Turn the System Back On

Now you can grab a beer and congratulate yourself on a job well-done.