Hello fellow UK420's sorry ive not been posting alot but this growing lark keeps me away alot


Right my problem please check my updated profile please as to best give me advice.
i am 4 weeks into flower and over last week i have humidity of 76% at lights out max and 45/50% min lights on my temps are 16C min and 22/23C max. Now im sure my last grow was lower but there is more plants and ive added the cooltubes ( i had just open budget reflectors ) , are they somehow causing it due to the heat now going away through the ducting and not burning the excess humidity in room when lights are on and keeping lower humidity through the lights out period due to it being lower in the first place when lights just go out. as my profile seems i think my air exchange is adequate. But its looking like i need a dehumidifier at this rate but as this is only a fix i cant see why the ventilation i have cant do the job.

any advice as always will be greatly appreciated

cheers guys/gals

peace and love

cooltubes need there own fan ! 4" rvk , you are losing pressure through your filter as its easier for the fan to pull the air through the tubes, so your losing extraction pressure .With alot of greenery you need ventilate, as i'm sure you know, more.hope this helps.

cheers solo i have took off the ducting from the cooltubes to the extraction fan and will reroute ill connect my 100mm vortice to the cooltubes n blow over them as ya said. hope this gets the humidity down many thanks

the warmer the air the higher the humidity, warm are holds more water, and more water will evaporate from the plants if the temp is up.

if you want the humidity to go down, you need to cool your room down more, ie, better ventlation overal, and more draw through the cool tubes. also make sure that the cool tubes are being vented to outside of the room, and not back inside.



shadow

not really ,warm can hold more water..in other words its capacity for 'water holding' goes up with temperature so the relative humidity will go down .

just think what happens to warm air when it cools , your kitchen window when its cold outside and your cooking in the warm kitchen will run with moisture....this is because the warm air (carrying water) meets a cold surface and the RH gets to 100% and the water precipitates ..the capacity to carry water goes down as the air cools and the RH goes up


so for a given space (your grow room ) if there is x grammes of water in the air and you raise the water carrying capacity of the air by upping the temp you will still have x grammes of water but the relative humidity will come down as the carrying capacity has increased.

raising the temp is a quick fix for high humidity levels ,obviously not appropriate in every situation but i've used it to lower the RH while the lights are off

Many thanks for all help i understand it a lot more. im looking at what the difference is over next few days. For a test i left the ducting hanging down from the cooltube run and room temps up to 24/25 c will check when lights on if RH changed due to more heat in the room. That plus Solo's advice on the pressure drop from my extraction is now rectified. Next time im in room ill reconnect the cooltubes with a spare 4 inch i have to blow over them and reconnect to the other side of my extractor going into the wall outlet. see how it goes. fingers crossed RH will drop


peace and love

Keep us posted,
solo