PlanetCatfish.com

I am considering purchasing one of these NR 5000 Nitratereductor 3000ltr from Aqua Medic. http://www.swelluk.com/marine/8-35-491

Has anyone used one in a fresh water environment and are they effective

Let's start by assuming you want to do this because you don't want to change water as much...

There are (in freshwater at least) other reasons than nitrate to change water, and that is the buildup of various organic waste-products that are not easily broken down. I'm not sure if the same bacteria can be used, however. I would think that marine bacteria are different ones than the freshwater ones...

The breakdown of nitrate works in an anaerobic environment, and as such, the machine you're pointing to should work. The reason that these are used for marine tanks is two-fold:
1. It's more work to change water in a marine tank.
2. Marine invertebrates are less tolerant to nitrate than most fish [marine or freshwater].



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Mats

The reason I was contemplating using one was not to reduce water changes but try and ensure that my Zebs are kept in the safest environment.

I think as long as you haven't got too many fish in the tank, you should be fine with just doing water changes - assuming your water that you add isn't high in nitrates that is.

But this link here is syaing that it works just fine with both fresh and marine water.

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Mats