Humidity

[Nightcrewman]

Hi just how important is humidity to the end result. we are struggling to keep humidity in the grow tent up its normaly about 50% but I assume this is too low. Could this be the reason our crop weight has been so bad lately.
The tent is 6X4X6 ft and the temprature is around 75 degrees. we have 5 plants in at the moment
Any advice welcome

NCM

Nightcrewman Reviewed by Nightcrewman on 06-04-2007. Humidity Hi just how important is humidity to the end result. we are struggling to keep humidity in the grow tent up its normaly about 50% but I assume this is too low. Could this be the reason our crop weight has been so bad lately. The tent is 6X4X6 ft and the temprature is around 75 degrees. we have 5 plants in at the moment Any advice welcome NCM Rating: 5

[Zandor]

50% is fine for most people. If you have AC and a closed room with CO² then more RH is great.

As you finish the last few weeks you need to get it down too that is to high for flower. To finish you should be aroud 25% - 30% and that will keep mold from getting a hold.

You need to have plenty of fresh air moving around your plants at all times.

But I would say you lower then expected yield may be something else.

What nutrients are you feeding them?

What supplements are you using?

What type of water?

How long do you veg them before you switch to 12/12?

What type of lights are you using?

You may want to check out my show if you are having problems the odds are in your favor that I already address most of your questions.

[Nightcrewman]

50% is fine for most people. If you have AC and a closed room with CO² then more RH is great.

As you finish the last few weeks you need to get it down too that is to high for flower. To finish you should be aroud 25% - 30% and that will keep mold from getting a hold.

You need to have plenty of fresh air moving around your plants at all times.

But I would say you lower then expected yield may be something else.

What nutrients are you feeding them?

What supplements are you using?

What type of water?

How long do you veg them before you switch to 12/12?

What type of lights are you using?

You may want to check out my show if you are having problems the odds are in your favor that I already address most of your questions.

Hi Zandor thanks for reply

How we are growing and what we are using.

We are using two 400w hps lights in a plastic green house approx 6ft by 4.5ft. the greenhouse is lined with mylar. The door is left open all day as they get too hot otherwise, generally sit at about 76 degrees. We have two bathroom fans cut into the roof to take away the hot air and an oscillating fan blowing on them when the lights are on.

I take my own cuttings, bring them on in an incubator and once roots are established (approx 2 weeks) move them into hydroponics with rockwool cubes giving them a feed level of 6 for the first week then up to 18 and a ph level of 5.5 to 6.2 with it as near to 5.8 as I can get and 18 hrs of light . this stage lasts about 3 weeks.they are fed with ionic grow at this stage and reach approx 2.5 â?? 3 ft.

I then move them onto 12 hrs of light and feed them on ionic bloom (though changed to vega flours this time) and also using the ionic boost during this stage. I have an air stone in with them at this stage to add air to the roots.

I use tap water in my hydroponics, use the gro tanks with water washing over them 24/7.



Cheers NCM

[Zandor]

What brand of nutrients are you using?

Try to move your air in to a lower point, You will find cooler air closer to the ground then you would the roof line. Running lights in the night with cooler nights it also an option. Increase the size of your exhaust fan and move more air out faster that will help too.

Is your light hood air cooled? If not that is the one change you can make to bring the temp down quick.

Do you pre Ph your rock wool before you use it?

if your humidity gets to high you risk white powder mold so keep an eye out and make sure you have plenty of air movement around your plants.

How is your tap water? What is the starting PPM? Do you let it sit out to evaporate the chlorine for 24 hours before you use it?

What about supplements?

Do you use Cal Mag Plus if not you should it's a great supplement for Hydroponics and helps keep plants healthy. If you still have heat issues there are some products you can use to help plants deal with stress better.

[Nightcrewman]

thnaks for reply, heres answering your questions.

Lights at night not a option here.

yes we do ph/feed level rockwool for 24hrs before using.

our tap water is soft. presume by ppm you mean the feed wand? our levels dont show on wand with just tap water, (meter starts at 4) we make up to 18.

no we dont sit water for 24 hrs but will do from now on

dont use supplements, at a quick net scan cal mag plus comes in different strengths - what strength do you recommend?

currently grow with ionic grow ( black bottle) and flower with vega fleur ( 2 part liquid).

as we say any hints much appreciated

am downloading some of the hydroponics lessons to watch and hopefully learn a lot.

[Nightcrewman]

are the grow reports avaiable in text format for reading? if not is it a consideration for you?

[mattmao]

the only thing i can sugest is to get rid of the ionic,ive used and was not impressed i also sufferd a drop in yield! so i now use advanced nutrients for the veg and then canna aqua flores for bloom with a little pk 13-14 when needed,i'm now getting the consistency in growth and yield back.cant be certain but i put my problems to the feeds.good luck mate.

[home.grower]

Everything Zandor said basically.

If your plants are healthy but simply not putting on the girth and weight that your expect then there are a few things to change:

1. more lighting
2. more air flow
3. more ammendments
4. change nutes altogether
5. etc

I've tried a small variety of nute brands and Advanced Nutes work best for me. I use AN - Mother Earth Super Tea Grow & Bloom; Sensi Bloom & Grow; Barricade; F1; H2; Big Bud; Overdrive; CarboLoad; and Voodoo Juice in the right proportions and quantities.

I wouldn't trade Advanced Nutes for anything else. Neither would I trade 3kW of HPS lighing for 125W of floro; nor a 10" acustic exhaust for a bathroom fan. Over time I've found that if you want the best from your girls then you have to create for them the ultimate environment, and then you must give them all the love and attention they need.

I used to use PK boost and I suppose it was orite, but the AN combinations have been developed especially for weed. It doesn't take away any guess work as one still has to decide whether or not they really think their plants really need the ammendment that AN suggests... I'm waffling, but don't skimp on love, thats the main additive for a bumber harvest and no shop will sell it to you.

[home.grower]

... gee it was supposed to be about humidity and not food...

I like low humidity thoughout. Copius resin production and narrow slender leaves. The narrow leaves allow for greater light penetration.

High humidity produces broad leaves and a dense canopy. Lower humidity has shown earlier resin production on my previous crops than with high humidity.

Low humidity = Less chance of mold - good for strains like sensi star that have very compact buds and develop mold if not carefully monitored.

I don't think humidity has affected the quantity of my overall yeild ever, besides losses from moldy colas which actually hurts when one has to throw prime cuts on the log burner. The Quality is affected though, but that is just my opinion and isn't a textbook suggestion.

Good luck matey!!

[Nightcrewman]

Everything Zandor said basically.

If your plants are healthy but simply not putting on the girth and weight that your expect then there are a few things to change:

1. more lighting
2. more air flow
3. more ammendments
4. change nutes altogether
5. etc

Hi home.grower

What do you mean by ammendments I've not come across the term B4