humidity raises over 25% with lights off ?

[elusiveshame]

I wouldn't be employing a dehumidifier at this point if you're trying to raise the humidity in your room. A humidifier is what you want.

His initial post was saying his humidity was getting to 68% due to one of his lights being out, otherwise you’re right. But he may need both depending on what his actual issue is.

 

[RootsRuler]

His initial post was saying his humidity was getting to 68% due to one of his lights being out, otherwise you’re right. But he may need both depending on what his actual issue is.

Time for a visit to the ophthalmologist....

 

[elusiveshame]

Time for a visit to the ophthalmologist....

Tell’m Kramer sent ya

 

[benjones]

When I went into the room a few days ago the timer failed to turn the lights on , so I turned them on manually. The rh was at 68% . After 15 minutes with the lights on it came down to 43%

I need the dehumidifier to bring the rh down when the lights are off

Thanks all for replying

 

[benjones]

@RootsRuler

I have 3 temperature and rh meters . One of them I sit on the light and dangle the sensor to about 8 inches below the top of a cola , it reads around 33%RH
The second meter doesn’t t have a sensor and reads about 58% . The third meter is a cheap non battery operated, it too says about 55%

I bought a dehumidifier and turned it on and it said the rh was 60%
I set it to 45 but it barely went to 58 . I now have air con on in the grow room and the room I bring the fresh air in set at 23c .

The dehumidifier is a Bwell BDH-20

The size of the room is 2.5 x 2.5 x 2.2 meters

If the dehumidifier can’t lower the RH , is there anything I can do with the AC temperature to reduce RH ?

 

[RootsRuler]

Before we move into how to lower or raise humidity I would first find out why you are having such different readings. Find out which of your meters is the most accurate and use that as your guide and disregard the rest.

As a general rule, the lower the temp the lower the humidity.

Is your humidity at 58%, according to your dehu, with the A/C on? If not the A/C should be able to provide enough dehumidification to bring your RH into the zone you want. Even if you can't get it exactly into the zone as long as it's close you should be OK.

 

[benjones]

thanks @RootsRuler

is there a way i can test each meter without having something to calibrate them against ?

 

[freezeland2]

thanks @RootsRuler

is there a way i can test each meter without having something to calibrate them against ?

Here is one method https://www.neptunecigar.com/tips/how-to-calibrate-your-hygrometer

 

[RootsRuler]

thanks @RootsRuler

is there a way i can test each meter without having something to calibrate them against ?

If you don't have a meter that you can use to calibrate you're going to have to go with what you got. You have 3 meters and a dehu. 2 out of the 3 are pegging your humidity levels at 55%+ and your dehu is saying 58%. Since 2 out of the 3 are within range of your dehu readings I would use your dehu as your guide.

Here is one method https://www.neptunecigar.com/tips/how-to-calibrate-your-hygrometer

There ya go!!!

 

[benjones]

Here is one method https://www.neptunecigar.com/tips/how-to-calibrate-your-hygrometer

thanks mate, i will give this a go tomorrow if i can buy some zip bags .

do you know of any accurate meters i might be able to buy . i am in thailand and have just bought these ones from lazada which is similar to ebay or amazon .

 

[benjones]

If you don't have a meter that you can use to calibrate you're going to have to go with what you got. You have 3 meters and a dehu. 2 out of the 3 are pegging your humidity levels at 55%+ and your dehu is saying 58%. Since 2 out of the 3 are within range of your dehu readings I would use your dehu as your guide.


There ya go!!!

would 58% be a problem . i think i can get it down to about 50% if i urn the temperature down to about 20C . i have about 2 - 3 weeks of flowering left

 

[freezeland2]

thanks mate, i will give this a go tomorrow if i can buy some zip bags .

do you know of any accurate meters i might be able to buy . i am in thailand and have just bought these ones from lazada which is similar to ebay or amazon .

No not really unless you want to spring for something like a wet bulb. Those ain’t cheap. Meteorology equipment.

 

[elusiveshame]

If you don't have a meter that you can use to calibrate you're going to have to go with what you got. You have 3 meters and a dehu. 2 out of the 3 are pegging your humidity levels at 55%+ and your dehu is saying 58%. Since 2 out of the 3 are within range of your dehu readings I would use your dehu as your guide.


There ya go!!!

Don't forget to mention where the locations of the hygrometers are. Different parts of the room will have different humidity levels. Closer to the soil (especially after watering) will have higher humidity than other spots in the room. Having a hygrometer in one plants canopy will read different from the next, one by the AC/window, closer to the light cone, etc. IMO, OP will need to check various spots over the course of an hour or 2 to find out where the trouble spots are and go from there, especially since the room is around 64^2'

 

[freezeland2]

would 58% be a problem . i think i can get it down to about 50% if i urn the temperature down to about 20C . i have about 2 - 3 weeks of flowering left

If you keep air moving around you can safely get buy at 50% in flower.

 

[benjones]

No not really unless you want to spring for something like a wet bulb. Those ain’t cheap. Meteorology equipment.

thanks @freezeland2

 

[benjones]

Don't forget to mention where the locations of the hygrometers are. Different parts of the room will have different humidity levels. Closer to the soil (especially after watering) will have higher humidity than other spots in the room. Having a hygrometer in one plants canopy will read different from the next, one by the AC/window, closer to the light cone, etc. IMO, OP will need to check various spots over the course of an hour or 2 to find out where the trouble spots are and go from there, especially since the room is around 64^2'

i will do this tomorrow , thanks @elusiveshame

the meter without a wire sensor is on top of the led light
the meter WITH a wire sensor is on top of another light but i dangle the sensor about 8-10 inched below the main cola just under some leaves
the other cheapo one is on the floor , i did move this one today and put it above the pot and humidity shot up to about 70%

 

[benjones]

If you keep air moving around you can safely get buy at 50% in flower.

what would be the danger zone ?

 

[benjones]

If you keep air moving around you can safely get buy at 50% in flower.

if i can't get the RH down via AC or the dehumidifier i will add another fan , i have 2 big ones and 2 small ones already , 6 inch extraction and inlet fan

 

[elusiveshame]

IMO, your hygrometers should be located between the light and maybe slightly below the canopy and if you have a third, in between the 2.

Your plants aren’t on top of the light, so those readings aren’t helpful.

Edit: just read that one has a dongle. I’d get it closer to the canopy if you can.

 

[benjones]

IMO, your hygrometers should be located between the light and maybe slightly below the canopy and if you have a third, in between the 2.

Your plants aren’t on top of the light, so those readings aren’t helpful.

very good point

i will adjust them all tomorrow and see how it goes . it's 11pm here and lights come on at 8:00am