Still struggling with temps......

Im still struggling with my temps , no matter what i do i dont seem to beable to get temp at canopy level down below 30 degrees celcius. A guy round my local hydro said that these temps would be fine with the strain i have(psychosis and s/cheese) . He also said that runner at a slightly higher temp would be fine as long as the humidity was kept at a low level. Is there any truth in this ? Or do i still need to be trying to get my temps lower ? If my temps stay the same will it affect growth/yield? They seem to be ok at the moment and if i hold my hand palm down at canopy level i can just feel the warmth comfortably from the 600w hps in the cooltube 12" away.

Move up the bulb. 600watt doesn't need to be 12" away, 24" is fine especially, although with a cooltube you can got a little closer there's no need to have it at 12" or even less than 20".

Hydro story guy has a point. Water potential is the driving force for transpiration (and hence influences water+nutrient uptake). Warmer air can hold more water than colder air, so it can have a higher water potential, causing water to move out the leaves in the air, which causes the plant to suck up new water through its roots. When it's very humid the air already holds a high amount of water already and the transpiration rate is decreased and the risk of plants drying out from the heat is increased.

Feed a silica supplement like GH's ArmorSi. Helps plants deal with heat, cold, drought, pests. I notice leaves are tougher, leathery.

thanks for all the pointers , ill move the bulb up tomorrow morning at lights on and see how the temps are I am feeding a light dose of silicon+ but using it more as a replacement for ph up , should i maybe increase the dose next rez change?

How big is the fan sucking the heat out of your cooltube?
How big is the fans taking cool air into the grow area?

Id rather try to fix the temp then try to turn my plant into a cactus to survive in a dessert.

fatc2k3 said:

should i maybe increase the dose next rez change?

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I use what is recommended on the label (5ml/gal for Silica Blast), stopping in early flower (because I don't know if silica could accumulate in the bud. Silica dust isn't good to inhale.). I start using it in week-2 at mild strength.(2ml/gal). I move up to full strength in week-3.

I'm in the process of changing to GH ArmorSi which says full strength is 2.5ml/gal and max strength is 5ml/gal. It has 10% silica whereas SB is 2%. So, I might use less. (Or, maybe I should have used more SB).

what do your leaves tell you ...are they shaped like a taco or shaped how they should be... you may have no need to add anything extra if they are shaped normally... imo 30 degrees is ok...over 34 and you need to do something about it

torontoke said:

How big is the fan sucking the heat out of your cooltube?
How big is the fans taking cool air into the grow area?

Id rather try to fix the temp then try to turn my plant into a cactus to survive in a dessert.

Click to expand...

2 x 4" fans bringing fresh air in , 1x6" fan on the cooltube sucking air out , 1 x 5" fan on carbon filter , 2 x6" clip on fans inside the tent to keep the air moving around.

WazzaX said:

what do your leaves tell you ...are they shaped like a taco or shaped how they should be... you may have no need to add anything extra if they are shaped normally... imo 30 degrees is ok...over 34 and you need to do something about it

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My leaves seem to be ok ? Little bit of clawing here and there on the older fan leaves.
Pics taken this morning , PH 5.9 (a tad above but they seem to like it there) EC 1.4 . Temps are actually down this morning to 26 degrees but its still early As you can see the tube is 1ft away from the tops of the plants. Also noticed the leaves that were on the clone from the start have yellowed off , is this to soon to be seeing yellowing , its only 2 weeks into 12/12 ?

I have noticed the white powder on the lowest leaves , wiping that with sterilizer.