• ******* To read about the changes to the marketplace click here

Using Dehumidifier water for top-off?

smcnally

Tankless
I know dehumidifier water probably has perfumes and stuff in the water that it pulles from the air. But I was wondering...What if I ran the water through carbon before adding it to the tank? I pull 3-5 gallons a day with my dehumidifier, and it would be awesome if I could just put the water right back into the tank.
 
I know dehumidifier water probably has perfumes and stuff in the water that it pulles from the air. But I was wondering...What if I ran the water through carbon before adding it to the tank? I pull 3-5 gallons a day with my dehumidifier, and it would be awesome if I could just put the water right back into the tank.

Sounds like a clever plan but you said that your pulling 3-5 gallons a day man thats a lot.I'm only saying this because I pull 3gal. every couple of weeks.
 
Sounds good to me, at least in theory. I think I'd be most worried about contamination from the dehumidifier itself. More so than contaminants from the air (the condensed water vapor should be perfectly pure - purfumes and other volatiles won't condense with it).

My dehumidifier is sometimes used in the basement so it's coils and fan are pretty dusty. If yours has always been used in clean areas then maybe that's not a problem.

If the coils are aluminum, you may get some aluminum oxide in the water, which probably wouldn't be such a problem. If your coils are copper, or tinned copper, I'd be much more wary. I know mine are silver colored, but I haven't looked closely enough to tell if they're stainless (I doubt it), aluminum, or tinned copper.
 
Sounds like a clever plan but you said that your pulling 3-5 gallons a day man thats a lot.I'm only saying this because I pull 3gal. every couple of weeks.

Big tank, big lights, big humidity! :) I had a 120-gallon total volume tank/sump, with similar lights to Steve's, and I lost a 2-3 gallons per day.
 
Sounds like a clever plan but you said that your pulling 3-5 gallons a day man thats a lot.I'm only saying this because I pull 3gal. every couple of weeks.
LOL...I have a 125 Gallon tank. It evaporates at least 3 gallons a day. If you have a decent sized tank, your dehumidifier isn't doing a good job.

Sounds good to me, at least in theory. I think I'd be most worried about contamination from the dehumidifier itself. More so than contaminants from the air (the condensed water vapor should be perfectly pure - purfumes and other volatiles won't condense with it).

My dehumidifier is sometimes used in the basement so it's coils and fan are pretty dusty. If yours has always been used in clean areas then maybe that's not a problem.

If the coils are aluminum, you may get some aluminum oxide in the water, which probably wouldn't be such a problem. If your coils are copper, or tinned copper, I'd be much more wary. I know mine are silver colored, but I haven't looked closely enough to tell if they're stainless (I doubt it), aluminum, or tinned copper.

Maybe I'll pick up a copper test and test the water coming from it. That's the only down side I can see. Maybe I can get a pressure pump and run the water through an RODI:D ...I don't think I'd bother if it took that though...
 
Last edited:
Guys I totaly forgot that tank water evaporates into the air and the dehumidifier could collect some of that back.I just started up my 120 a few days ago its ben so long.I guess i'll be running my dehumidifier a lot more now.Steve if you do run the carbon let me know how it turns out.
 
many yrs ago, there was a thread about this subject and the LFS up north that closed and became an astrology store was doing a test on the water from a dehumidifier and whether it was viable or not. I don't recall what the results were or whether the thread was on our old site on RC....some old time reefers will have to help me out here on this answer.....
 
Guys I totaly forgot that tank water evaporates into the air and the dehumidifier could collect some of that back.I just started up my 120 a few days ago its ben so long.I guess i'll be running my dehumidifier a lot more now.Steve if you do run the carbon let me know how it turns out.

Just a reminder, as you are learning the ropes. Don't forget to top off with pure water, not salt!
 
Evaporated water

Our 220 gallon evaporates about 35 gallons of water a week which I top off in the sump. The salinity has been very regular and with occasional water changes the water stays perfectly where I want it.

I have noticed with this much humidity in the water I have many fewer kids sick during the winter. The dry air is not good for the most part and I like the warmth that it puts out as well.

Don't know much about dehumidified water as I leave it all in the air.



Guys I totaly forgot that tank water evaporates into the air and the dehumidifier could collect some of that back.I just started up my 120 a few days ago its ben so long.I guess i'll be running my dehumidifier a lot more now.Steve if you do run the carbon let me know how it turns out.
 
Some humidity in the air is good for you. But, IMO, the amount that a large fish tank adds to a house is not. Anything over 40% will cause condensation on your windows in your house during winter months. That alone can and will damage window sills. It will also promote mold growth in your home. Mold=Unhealthy
 
Just run the dehumidifier water through a Carbon block, then DI resin. I am sure that will take care of any contaminents.
 
Just run the dehumidifier water through a Carbon block, then DI resin. I am sure that will take care of any contaminents.
That's what I was thinking. It would be nice to not have to empty the dehumidifier too! :D
 
I wonder if you could gravity feed it from the Dehumidifier reservoir, via PE tubing, into a carbon cartridge, and then a DI cartridge. It would be nice if you could do it all without using a pump, and I'd guess that since the flow out of the dehumidifier is very slow, it might be possible.
 
I'll have to try filtering the water and see what I get. I haven't found a copper test yet, but out of curiosity I tested the pH of the dehumidifiers water and it is 7.4.
 
If the water is fairly pure, pH is meaningless, because pure water has no buffering capacity, so the pH will swing wildly if you breath on it, and will instantly adapt to any other solution you add to it. So you could add a gallon of pH 6.5, TDS 1 RODI water to your one gallon tank at pH 8.3, and the resulting tank pH would be 8.3.

What's the TDS of your dehumidifier water?
 
Back
Top