Using dehumidifier water?

S

Smokesteve

Well-Known Member
I have a new dehumidifier in my garage draining into a new 5 g bucket. I grow organic w liquid nutes. Any opinions on using the dehumidifier water would be much appreciated. Thank you
 
ounevinsmoke

ounevinsmoke

Well-Known Member
I tried to run a small DWC in a 30 gallon tub with Dehumidifier water. For some reason when I added my nutes to that water and then tried to use my PH meter it went absolutely berserk. My TDS Meter was thrown off as well. Numbers just jumped all over the place and sometimes they would error. My plants developed dark brown spots on them after a few weeks. I was baffled so I asked around here in RIU. The most solid explanation someone gave me is that dehumidifiers generally use cheap coils and low quality condensers that contaminate the water so you are truly not receiving a pure version of water. It leaves metals or other contaminants in the water that react with the nute mix and cause issues. I don't know if any of that will happen to you and your water, but I could not use mine so I bought a rain barrel and attached it to my gutter. I usually bought the cheapest 70pint dehumidifiers from whatever Walmart was selling at the time. Good Luck, Happy growing!
 
ttystikk

ttystikk

Well-Known Member
ounevinsmoke said:
I tried to run a small DWC in a 30 gallon tub with Dehumidifier water. For some reason when I added my nutes to that water and then tried to use my PH meter it went absolutely berserk. My TDS Meter was thrown off as well. Numbers just jumped all over the place and sometimes they would error. My plants developed dark brown spots on them after a few weeks. I was baffled so I asked around here in RIU. The most solid explanation someone gave me is that dehumidifiers generally use cheap coils and low quality condensers that contaminate the water so you are truly not receiving a pure version of water. It leaves metals or other contaminants in the water that react with the nute mix and cause issues. I don't know if any of that will happen to you and your water, but I could not use mine so I bought a rain barrel and attached it to my gutter. I usually bought the cheapest 70pint dehumidifiers from whatever Walmart was selling at the time. Good Luck, Happy growing!
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Something wrong with your setup or how you added nutes. Never use a pH meter in pure water.
 
ounevinsmoke

ounevinsmoke

Well-Known Member
ttystikk said:
Something wrong with your setup or how you added nutes. Never use a pH meter in pure water.
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Was a 30 gallon tub full of dehumidifier water. I added 3 part GH series micro first. Never had a solid read TDS, or PH. Never tried to PH water by itself. It was the water I assure you because when I used other sources everything went back to normal.
 
ttystikk

ttystikk

Well-Known Member
ounevinsmoke said:
Was a 30 gallon tub full of dehumidifier water. I added 3 part GH series micro first. Never had a solid read TDS, or PH. Never tried to PH water by itself. It was the water I assure you because when I used other sources everything went back to normal.
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Very weird because I used to fill a 32 gallon trash can with distilled water every other day. Added nutes and ran it over and over and over...
 
CanadianJim

CanadianJim

Well-Known Member
The only problem I can see is that bacteria from the environment can grow in the reservoir as it is a damp dark place. I've been running a dehumidifier 24/7 (except in winter, it's onboard sensor shuts it off when it gets below 30%) for a few years now. I've noticed a yellow film in the bottom of the tank when I empty it. While these bacteria are already in the environment, I would be wary of adding a concentrated dose of them to your plant. You might want to boil the water if it's been sitting in the tank for any length of time. Or regularly sterilize the tank with H2O2. It degrades into oxygen and pure water, so adding a dose of it then letting it sit for 24 hours would kill any bacteria in the water, without damage to the beneficials in your soil or nutes. An airstone in the bucket would speed up the process.
 
G

growingforfun

Well-Known Member
ttystikk said:
Very weird because I used to fill a 32 gallon trash can with distilled water every other day. Added nutes and ran it over and over and over...
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What do you think that metal is shimmer on the top of the water is? I know I wouldnt drinking, but I feel ok using it on my veg
 
Merlin1147

Merlin1147

Well-Known Member
I use dehumidifier water through the grow without problems. It will stabilize at a pH of around 5.7 as it adsorbs CO2 which convert to carbonic acid.
 
ttystikk

ttystikk

Well-Known Member
Merlin1147 said:
I use dehumidifier water through the grow without problems. It will stabilize at a pH of around 5.7 as it adsorbs CO2 which convert to carbonic acid.
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This note is for everyone who pH tests their water;

WATER HAS NO PH

It's what it's in the water that gives the resulting solution a pH. Distilled water has nothing in it. Whatever number your meter gives you is not likely to be accurate.

The lower the EC value of the solution, the less acidic or basic material one needs to add to change it.

Higher EC values will buffer the solution, meaning that you add pH up or down and it doesn't change much. Then a threshold is reached, past which the buffering effect is overcome and pH changes rapidly.

This is why there is no point in attempting to pH balance water until after you've added nutes to it.
 
ttystikk

ttystikk

Well-Known Member
CanadianJim said:
The only problem I can see is that bacteria from the environment can grow in the reservoir as it is a damp dark place. I've been running a dehumidifier 24/7 (except in winter, it's onboard sensor shuts it off when it gets below 30%) for a few years now. I've noticed a yellow film in the bottom of the tank when I empty it. While these bacteria are already in the environment, I would be wary of adding a concentrated dose of them to your plant. You might want to boil the water if it's been sitting in the tank for any length of time. Or regularly sterilize the tank with H2O2. It degrades into oxygen and pure water, so adding a dose of it then letting it sit for 24 hours would kill any bacteria in the water, without damage to the beneficials in your soil or nutes. An airstone in the bucket would speed up the process.
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The plants see all that bacteria, even if they're in grow rocks or coco.

No boiling needed.
 
G

growingforfun

Well-Known Member
ttystikk said:
Metal flux left over from manufacture is my best guess. It won't hurt anything and should rinse out over time.
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Possibly, but I've noticed it for a long long time... talking years of near constant use one units, get new units, see the same thing. If it lasts until a new unit is bought and its seen in new units not just one unit, but in 5 diff units for the whole lifespan then....?

Just for me I wouldnt use it on flowering plants.
 
CoB_nUt

CoB_nUt

Well-Known Member
ttystikk said:
This note is for everyone who pH tests their water;

WATER HAS NO PH

It's what it's in the water that gives the resulting solution a pH. Distilled water has nothing in it. Whatever number your meter gives you is not likely to be accurate.

The lower the EC value of the solution, the less acidic or basic material one needs to add to change it.

Higher EC values will buffer the solution, meaning that you add pH up or down and it doesn't change much. Then a threshold is reached, past which the buffering effect is overcome and pH changes rapidly.

This is why there is no point in attempting to pH balance water until after you've added nutes to it.
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I've often wondered about this,when mixing up my nute or adding down. At a certain point the down seems to "break thru" the buffer and I have to ease up on the drops or I'll overshoot my target ph due to the broken buffer allowing rapid change.

Thank you.
 
ttystikk

ttystikk

Well-Known Member
growingforfun said:
Possibly, but I've noticed it for a long long time... talking years of near constant use one units, get new units, see the same thing. If it lasts until a new unit is bought and its seen in new units not just one unit, but in 5 diff units for the whole lifespan then....?

Just for me I wouldnt use it on flowering plants.
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Then maybe there's something wrong with your unit.

I've had fine results. The best part is that distilled water has zero dissolved solids in so everything added is plant food.
 
Merlin1147

Merlin1147

Well-Known Member
ttystikk said:
This note is for everyone who pH tests their water;

WATER HAS NO PH

It's what it's in the water that gives the resulting solution a pH. Distilled water has nothing in it. Whatever number your meter gives you is not likely to be accurate.

The lower the EC value of the solution, the less acidic or basic material one needs to add to change it.

Higher EC values will buffer the solution, meaning that you add pH up or down and it doesn't change much. Then a threshold is reached, past which the buffering effect is overcome and pH changes rapidly.

This is why there is no point in attempting to pH balance water until after you've added nutes to it.
Click to expand...
Excellent points here, except the first one. Technically speaking, All water has a ph. Even the purest sample of H2O will have random H+ and OH- ions which will balance out giving a ph of 7.
 
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