hi all
ive got a small problem that could develop later on in flower,and i need a bit of help
1.2m x 1.2m x 2.0m tent
600w
100mm tt intake taken from loft
125mm tt exhaust with budget filter to outside
2,6inch clip on circulating fans
1kw oil rad on lights out

lights on temps 27-28 humidity 30-35 %
lights off temps 18-19 humidtiy 70-80%

in the last few days,i seem to be getting condesation build up around the walls of the tent below the canopy
the problem seems to have developed just recently,
im day 1 of week 5 into flower and worried about the high humidity,ive suffered with bud rot before so need to avoid.

im trying to avoid the use of a dehumidifier,as with correct air exchange these should not be needed
where am i going wrong with my intake and extraction?

any tips for this type of set up will be appreciated

regards
biz

I use a dehumidifier as I get humidity spikes from the ambient atmosphere. Good air circulation can only do so much. If you can, get a larger diameter extraction system going. Better extraction never hurts.

Hi mate, its a simple answer, you need a bigger exrtaction fan, 125mm with CF fitted isnt upto the job, you need at least a 6 inch fan and CF running full power 24/7.

e2a: You were right when you said:



.....but using a dehumidifer will be ok (for lights out) if you cant afford a bigger fan/CF yet, but only have it running on minimum.

Where are your clip on fan's I find one oscil-fan on the floor and clippies over the top's improve my circulation, it may seen a simple question but what is the rh of your loft? if that's moist then maybe look to draw the air in from the ambient area round your tent.

Firstly, current UK humidity levels are what you are getting in your grow and are 70 -80%

The levels of absolute humidity is exactly the same for both lights on and off, only relative humidity is changed, but that's what you're worried about.

Aside from getting a dehumidifier, another remedy is to reduce your air intake at lights off, so that the heater will be more effective and raise lights off temperature above dew point, which means no condensation.

Your air flow through the grow on lights on should be approaching 200m3/hr. Your air flow on lights off need only be the basic 20 air changes/hr, about 6om3/hr, so 75% less air for the heater to work against.

You obviously have to test, but I would suggest shutting off the intake fan at lights off. If that does not raise temps enough, then slow the extract fan down, but not below 60m3/hr.

Cheers,a dehumidifier may be the solution




thanks,if funds allow ill get a 150mm fan and filter soon,if not ill have to have a go with a small dehumidifier




ive moved the intake to along side the tent,hopefully this will make a difference
ive also got a fan that i could place on the floor of the tent,ill give it ago




i think the 100m tt intake may be on full power ,ill check tomorow and switch to the lower power setting
thanks for the input guys much appreciated,ill let you know how thing pan out

P.S.
these boards are great any probs you guys are always there

A 1kW rad should have lights off temps higher than that. Wind it up a bit and set it's timer so that it comes on a half hour before the lights go off and stays on until 15 minutes after the light comes back on.

When I was doing my nut in trying to grow mould free in 80%RH, that's what stopped the raindrops forming on the reflector.

hi chaps
the condensation dispearred not this morning
got a max of 64%humidity
ill up the time on the oil rad as lazi suggested maybe we can get it down abit more
what are people thoughts on using a timer to decrease the inlet maybe 30mins on 30 mins off during lights out only to keep the temps up?

Ive used those silica gel bags befor, like the 1s u get with a pair of new shoes but only bigger 500g i think. Not sure how powerful they are but always handy.

They sell something like them in morri's usually where they have the car stuff/paint brushes etc I think they are 3 squids or there abouts

along the same lines of the silica gel i have some dessicant that we use at work
ive place a small bucket of that in the grow room see if it makes any difference
timered the intake

i think 1 problem was that i had my hygro meter tape to the tent wall
as soon as i hung at the canopy my humidity dropped by over 10% to 50%

last nights humidity maxed out at 70 so it has dropped a bit

whats the ideal humidity for lights out in the later stages of flowers please guys ?

Are you running your extractor 24/7?

For a 600w in a 1x1x2.... Based on my own experience.... I would agree with this :-

yup 24/7
trying to get a 150 fan from a freind as we speak

well got the de humidifier as the changes i made to the set up didnt really drop it
ive got 6inch fan aswell to put so hopefully can control my RH a bit better

well ive got enviroment sorted now.
got me self a 150 tt fan and odur sok for extraction
its got rid of the condesation immediatley
ive now got a max humidity of 64% min 39%
but more importantly the condensation has disapeared,got to be good thing as we enter week six

again a big thanks for pointing me the right direction guys

Cool man.

I found precisely the same thing when I upgraded my extraction... within a couple of days, everything was perfect