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Koi Pond Maintenance

Water Changes/Waste Management:

For my water changes, I wanted a way not to waste water, but needed to figure a way to try to remove the crap (literally the fish poo) from the bottom of the pond. I searched high and low on the net and could not find much really, or was not really satisfied with the answers I saw. In the end I did come to the conclusion that to have a indoor pond, you need to clean the crap off the bottom. The bio-filter can only do so much, i.e. take out some of the nitrogen, but it wont keep the water from getting too nasty with food/poo/plant debris on the pond floor.

One thing I could have done was buy a more powerful pump and make or buy a pre-mechanical filter that would suck larger particles (hopefully not the fishies) in and either trap it or pump it into the bio filter (and hopefully not clog the pump). After contemplating for a while, I just realized, vacuuming will be the easiest. I have a small siphon but really it takes a while to do much with, and it doesn’t suck up enough fast enough.

Lee's Ultimate Gravel Vac (50')

The best option seems to be using the Venturi System-Gravel Vacs. They have different brands but I didnt want to spend too much money so I went with the:

Lee’s  Ultimate Gravel Vac from

This works by connecting one end to a faucet, and by using the principles of fluid dynamics, it creates a pressure gradient in the tube hence creating a vacuum. You can see more explanation here on Wikipedia or with a google search. If I have the time I will try to provide my own explanation for how this works.

Anywhoo, it works great. Only problem is that there is a lot of wasted water, but my pond was getting nasty to the point that I didn’t care. I was using the manual siphon, and using the waste-water to water my plants. I figured the nitrogen would be good fertilizer, but then again too much fertilizer will kill my plants off.

Once you are done cleaning, you can easily fill the pond up with the same Gravel Vac. It has this nice nozzle that you can flip and it redirects the water from suck to fill. I did not want to kill my fishies off with the chlorine, so I had to air out the water in a large plastic tub overnight. I would then use my bio-filter pump, and pump the fresh water in the next day.

[Video of the Cleaning to come]

Overall, it appears the most effective way to clean an indoor pond is to just vacuum it. No way around it really.

So far no dead fish yet, and they are growing bigger!!


Water Treatment

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