# Anyone actually tried using dehumidifier water in their tanks?



## Midland (Jan 26, 2015)

Hi there one and all,

I have had a small marine tank with common soft corals (mushrooms, blastomussa, acans, euphyllia) for about four years now. Seeing the tank is small, I have always bought water from a water store for top up and water changes. Like many of us, I also have a dehumidifier that I end up emptying on a daily basis.

I realize from my research that many people suspect that dehumidifier water could contain copper or other traces that could be harmful to coral and that the dehumidifiers come with warnings of not for use for human consumption. However, nothing I read about marine use was conclusive and I hear of people using tap water etc. which I would suspect has copper (especially in homes with copper piping).

So, has anyone ever actually used dehumidifier water in their tanks and had problems or successes?

I am looking into have the water from my dehumidifier professionally tested before doing anything, assuming the cost of the test is reasonable. In the mean time, I thought I would see if anyone had actual experience with doing this.


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## carl (Feb 11, 2010)

It’s got all the other stuff that was mixed with the water vapour in the air, VOC’s and anything else off gassing in your house so you shouldn’t use it


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## wtac (Mar 17, 2006)

Condensers in household dehumidifiers are made from aluminum. The big issue is what solids and microbial organisms that will be in the condensate.

As Carl mentioned, you will get VOCs but not much more than if you aerate RODI/NSW with an pump and airstone.


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## characinfan (Dec 24, 2008)

I'd be concerned about mould growing in the dehumidifier.


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## Midland (Jan 26, 2015)

Thanks one and all. I will look into if any tests are available for the microbial and other issues. If the test is relevant and not overly expensive I will get back to everyone about what the results are.


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## solarz (Aug 31, 2010)

One of these days I'm going to run an experiment to see if dehumidifier water can be used as top off water.

Mold and microbes aren't an issue, but aluminum might be.


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## fesso clown (Nov 15, 2011)

"cause reefkeeping ain't hard enough....


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## Midland (Jan 26, 2015)

solarz said:


> One of these days I'm going to run an experiment to see if dehumidifier water can be used as top off water.
> 
> Mold and microbes aren't an issue, but aluminum might be.


Aluminum is one of the substances I asked the lab if they test for.

And Fesso, I agree - I am hoping to have the tests done because I realize how easy it can be to complicate this hobby!


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## littletnklvr (Nov 1, 2010)

If you have a tank running for 4 years and everything is doing great why would you want to risk losing any or all of it?


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