Dehumidifier water safe for fish?

[cooledwhip]

I just bought a new humidifier on sale for the basement and I want to know if the water is safe to dump into my fish tanks. I figure why not reuse some water plus I assume it's safe to use because it's purified through reverse osmosis if I believe so.. I heard somewhere that it's really low pH water. Thanks

 

[Baccus]

If the dehumidifier also sucks or collects dust particles then I would not use that water in your tanks, it probably would also collect any airborne chemical contaminates that may be present in the room too, such as air fresheners or fumes from other chemicals stored in the general area.

 

[StevenF]

It is not revers Osmosis water. It is distilled water condensed directly out of the air. Yes it will have some dust in it and maybe some fumes and air pollution in it.. That dust also lands in the aquarium. air pollution also gets in with the oxygen the fish breath. So your fish have already been exposed to those things.

distilled water has essentially no minerals in it. Meaning it has zero KH, GH. it also readily absorbs CO2 from the air which means it will be mildly acidic. like RO water it should be mineralized before adding a significant amount of it to the aquarium. If you just adding it to compensate for evaporation of the aquarium water it doesn't need to be remineralized.

 

[AbbeysDad]

NO!
I have high nitrates in my well water so I have to filter it to remove nitrates for partial water changes. I ALSO thought that the water from my basement dehumidifier would be as pure as distilled water - after all it's just condensed water from the moisture in the air. I used it for a time. Then recently after a partial water change I noticed several of my fish in distress. Clamped fins, some flashing, and gulping air at the surface. I quickly treated with prime and did some testing. I discovered that the water from my basement dehumidifier was off the charts high in AMMONIA. I still don't understand how or why. Afterwards I did a google and learned that high ammonia levels in dehumidifier water is fairly common.
In the week or so that followed the incident, I lost 5 fish.
Lesson learned and I'll never use it again. If you still think you will, be sure to test it first.

https://www.google.com/webhp?source...pv=2&ie=UTF-8#q=ammonia in dehumidifier water

 

[NickAu]

I actually looked into using a dehumidifier instead of RO, this makes for interesting reading.
http://www.planetcatfish.com/forum/viewtopic.php?f=2&t=27073

 

[DrRob]

Yeah, in principle it's great, a byproduct source of distilled water. Problem is the way it does it, cool the air and see what condenses, which won't always be entirely water. For distilled water you'd select out by boiling point to get pure water, in this case it's whatever happens to be in the air. If it's mainly water then it's all good, if it's not then you've no idea. Ammonia is relatively volatile, so if it's present in the house then it's no great surprise to find it in the dehumidifier. For us it'd be household cleaners to blame for that one.

I played with it once, dumped some daphnia in it, 2/3 water from their tank, 1/3 dehumidifier. With them all dead in 20 minutes I chucked the lot out.

 

[cooledwhip]

Yeah I understand you guys are right. But if it's high in CO2 and mildly acidic I think it would be great for terrestrial plants or possibly plant only aquatic tanks... I grow lots of citrus plants and coffee plants. I'll try and use it for them. Dust shouldn't be a problem.

 

[NickAu]

A wise man once told me it is best to keep fish that can live in the water that comes from your tap with just a bit of dechlorinator added, and he was right.

All this playing with water chemistry relies on too many external factors and can cost lots of money.

Thanks Byron.

 

[StevenF]

The moral of this story is to always test new water sources before you put that water into the tank. Although that said ammonia in dehumidifier water should be investigated. If the ammonia is in the air you breath it could negatively affect your health after years of breathing it. Possible sources are missing P traps under sinks. Insufficient bathroom venting fans, excessive use of ammonia based cleaning produce and outdoor air pollution.

eah I understand you guys are right. But if it's high in CO2 and mildly acidic I think it would be great for terrestrial plants or possibly plant only aquatic tanks...

I did some research earlier High CO2 levels in water equates to a PH of 3. This is not mild and it occures when the water is saturated with CO2. Most aquarium test kits bottom out at 6. if your test kit is at it's lowest reading I would not add the water to the aquarium. Outdoor terrestrial plants are already exposed to CO2 rich acidic water, called rain.

 

[AbbeysDad]

The moral of this story is to always test new water sources before you put that water into the tank. Although that said ammonia in dehumidifier water should be investigated. If the ammonia is in the air you breath it could negatively affect your health after years of breathing it. Possible sources are missing P traps under sinks. Insufficient bathroom venting fans, excessive use of ammonia based cleaning produce and outdoor air pollution.

In my case, it's a basement - no sinks, no bathroom, no cat litter box, no ammonia based cleaning products....nothing I can figure to explain ammonia in the condensed water.