I am really needing advice on siphoning sand substrate in a pool pond!


Feeder Fish
MFK Member
Oct 8, 2017
Hi, I have an indoor freshwater 500 gallon Intex 8 foot diameter pool pond in my basement. It sits on insulation boards on a concrete floor. The basement is insulated. It has been set up for almost a year now.
I have a total of 16 fish living in the pond:

8 sun catfish
2 feather fin synodontis catfish
yellow lab cichlid
4 peacock cichlids
Senegal bichir

I use three large flat box pond filters and two hydro5 sponge filters which comes out to about 2000 gallons of filtration. I don't use a heater on the pond I just heat the room. For the substrate I use pool filter sand. I do 20-30% water changes once a week. So far all the fish seem healthy and happy and I am really loving the pond life. :)

The problem I am having is that so far I have not been able to keep the sand very clean. Since the pond sits on the floor low to the ground, regular aquarium siphons won't work because they are gravity fed. I have tried to siphon the sand in the pond with a Python water changer but that doesn't work either because I don't have a strong enough water pressure coming out of the downstairs tap in my basement. I am also ruling out pond vacuums because they are outrageously expensive. The only thing that has worked some what better is using a wet/dry shop vac. But you have to be careful because those have a very strong suction and can suck up the sand completely which I don't want, and they will spit back dirty water back into the pond. I have also tried scooping it out with a net but doing that just dirties the water column. I just want to be able to siphon the fish waste off the sand to keep it clean.

To all you fish keepers out there that have pool ponds and use sand for the substrate, how do you siphon/keep the sand clean in your pool pond?


MFK Member
Jan 8, 2012
I don't have a pond, but I use a python for the pool filter sand in my tank. They make extensions for pythons and if you have another tap with enough pressure, I would try that. It's not ideal but will get the job done. That's a really nice sized pond for those fish, I would love to see some pictures!


Redtail Catfish
MFK Member
Mar 2, 2017
New Zealand
Sounds like you need to get a water pump. I'd suggest a dirty water pump, but I'm having trouble finding one that is inline rather than submersible. I think you'd want an inline definitely. Unless you put in a big inline filter before a regular pond pump or something.


MFK Member
Jan 30, 2007
If you can't afford the right equipment, I would siphon from pond into a large container beside the pond. Suck up the sand as you need which can be returned to pond later.

Use a float switch activated pump in the container to return water back to pond (or to waste). Keep pump off the bottom so sand doesn't get pulled into pump impellar.


Feeder Fish
MFK Member
Oct 8, 2017
I am wanting to know how people that have indoor ponds with sand for substrate keep their substrate clean. In an aquarium you can use an aquarium siphon to siphon the fish poop off the sand, but that is not possible using those on a pond that sits on the ground because they are gravity fed. I was really hoping that indoor pond owners would chime in on this thread and share how they keep their ponds clean?


MFK Member
Oct 3, 2005
I'm pretty sure there are external (or dry) type sump pumps that you can adapt to vinyl tubing. Just attach the python at one end and run the outlet to your drain.
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Fishman Dave

Giant Snakehead
MFK Member
Nov 14, 2015
West Yorkshire
Similar sort of issue with a 1600 gal indoor pond built above ground. Whilst I have gravel on this system I have the same issue but utilise two giraffe catfish to keep the gravel moving/ filtered clean.
I also have two large (180g) tanks on the floor with sand substrate and use pressured water return to blast the sand, whilst this dirties the tank water I then do a 30 percent water change whilst also connecting a spare mechanical filter with fine matting to help Polish the water. The next day after the water change I then clean 50 percent of the tank filter media and remove the temporary filter.
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