too much light?

[keepleft]

is there such a thing as too much light???

 

ive just moved ladies that are 3 weeks into veg (2 foot tall) from a veg G-room which has 50 watts per square foot of MH light, into the flower G-room where they are beeing trained into a SCROG.

 

the flower G-room has 90 watts per sqaure foot of mixed MH and HPS light (approx 60/40 ratio). is this too much light?

 

note the temp in the veg and flower room averaged about the same at lights on(30 - 32 degrees at the canopy)

 

the reason im asking is that once they were moved, half of the bigger ladies seemed to wilt slightly. the wilting was uniform (all over) but only affected the bigger ones

 

when they were in the veg room the leaves were straight and sharp. in the new room the bigger ladies leaves are drooping.

 

if htis due to too much light? or im thinking it could be that they need more irrigation/watering due to the increased light? (they were gettting 1lt every 3hrs in the veg room, when i moved em to the new room i increased this to 2lts every 3hrs - but the slabs felt alot drier after 2 days and i was unable to extract any water/nutes from the slab with the syringe to test!). ive increasd the watering to 1lt every hour and will see in 2 days if that changes the appearance.

 

would the leaves drooping be a result of dehydration/under watering? what is the difference in appearance b/w over and under watering (i think over watering the tips of the leaves curl downwards)? (p.s. im paranoid of overwatering cause these are brand new strains and i dont want to encourage pythium!)

[SukonmiSkunk]

90 watts per foot is a massive amount... you only really need 30watts per foot..... my room is 4'x8' with 2 600watters... it gives me nearly 40wats per foot...that is really heaps.....

how ever if you say the temps are around 32 at the canopy..that doesnt seem too bad..maybe increase the water you are giving them... with the extra light and warmth they will really suck the water.... and when they flower they will suck a hell of a lot more.

 

maybe try and get your wattage down to about 60 per foot..if that dont work.... I read on here some where that Hanky said about 50 watts per foot :thumbsup ...I would be aiming somewhere around there......

 

see how ya go :smoke

Edited February 28, 2006 by SukonmiSkunk

[F420]

50watts is MINIMUM for a decent yeild.

Plants can get too much light and it leeches them, kinda goes yellow.

[Roadblock]

Hi

 

Mate when my girls are at the 3 wk veg mark you could have a dripper run for an hr every 2 with no problems at all , a slab or pot fed with a dripper will have water flow to the drain like a winding downhill river depending on the cut and consistancy of the rockwool ( lots of variation) , every noticed how some slabs hold much more water than others, its because of density and cut direction of the rockwool , surrounding the rivers water will slow soak like wick feed to the outer reaches of the Rockwool medium , as Rockwool is like a cigarette filter in reverse , it will catch less salt where the rivers run and build up from there to the outside which can get real high if your not carefull , when a plant is growing it will build its root structure from those rivers where its main feeders are , did you move your drippers when the girls went to the flower room as you may have placed the dripper in a different spot which could cause new rivers away from the main feeder roots , so the plant stresses slightly while it adjusts its root system , this could be the reaction your seeing , once again another reason why I like high volume flow and medium frequency with Rockwool once the plants have formed a great root system ,, you do that by running very controlled low volume ( high air ratio ) and low nutes of around 8-12CF for veg and flush them once a week by running your tank for an 1hr or so just before lights out and a nute tank change , then let the slab get very dry , this is what develops roots bigtime and repeat the low volume cycle untill you go to flower , then give it to them , just make sure you are using low nute strengh untill you up the flow volume .

 

For lights 30 to 50 is a good range of balance , they will fill out no probs plus the lower demand will cause you are less possible problems , you can also get more out of your plants by finding its flower point , I had some Skunk-1 once that would flower fully at 13-1/2 hrs , that gave me over 80hrs extra grow within the same 8wk flower , I didnt grow the 8 though because 7wks was the same as doing 8 on a 12 hr regime , that converted to an extra crop a year .

 

Rod

[thc24]

I use a bit but not that much est 40 sf, if anything my buds get too big and chunky more light does not mean more bud. Have heard of people using like 4 or 5 400 wt in a meter square, you would expect 40 to 50 oz but they have been getting 15.oz of nice buds. stick within range mentiond by others as 50 would be ideal . To get good coverage from young to finnish you need the light about 60 cm for 600wt 40cm for 400wtfrom tips and raise every week .

[keepleft]

you only really need 30watts per foot.....

<{POST_SNAPBACK}>

 

HI SS. i dont think 30 watts per sq foot would cut it (in my setup anyway). my veg room is 50 watts per sq foot. they grow nice in there, BUT when I switch them to the other room which is 75 watts per sq foot they grow CRAZY NICE! The intenodes are tighter, the branches thicker and the growth rates much faster. The temp in that room is actually a bit cooler (2 degrees cooler than the veg room despite the increase wattage. This is because of bigger fans and also the position of the room (sun sets other side of house).

 

However, I have never tried it at 90 watts per sq foot. This is the first time. I wasnt concerned initially about having that much intencity as but I was just shocked to see some slightly wilting after 2 days moving up from the 50 watts to the 90 watts.

 

"how ever if you say the temps are around 32 at the canopy..that doesnt seem too bad.."

<{POST_SNAPBACK}>

 

Yep i ALWAYS make sure the canopy temps stay reasonable with an IN/OUT thermomter/hygrometer. The OUT positiong is planced directly under the light on the highest point of growth. At lights on 6pm in veg they can creep up to 33-34 but as it gets dark i find they come back to 29-30 as the air intake cools down. After midnight its 27 degrees when the nights are 15 degrees outside. On the nights when its stinking hot outside, i switch a few lights off. BUT ive found (and Roadblock i think you mentioned this too) that even mid 30's they still power on.

 

increase the water you are giving them... with the extra light and warmth they will really suck the water.... .."

<{POST_SNAPBACK}>

 

thats what ive done. i increased the watering from 1 lt per 3 hours to 1 lt per hour (lights on only). I usually take a sample from the slab, but it didnt have enough moisture in it to give me a sample! I figured that has to be tell tale sign of lack of irrigation.

 

thanks

[SukonmiSkunk]

would be good to see some pics of this..... maybe I could up my 600's to 1000's......

seems like they are loving it in there then..... kool

Ive just never heard of using that much light b4. when I first started my 1000's would do a 6x6 space with unreal results..never really had any problem with fluffy buds b4..... but more light if it helps is certainly viable...

I would be interesed to see how you go....... I might be in need of a change..

[keepleft]

every noticed how some slabs hold much more water than others,  its because of density and cut direction of the rockwool ,

<{POST_SNAPBACK}>

 

 

Hi rod good to hear from you. You know your rockwool!

 

yep sure have. I recently switched to VERTEX FATT BATTS from grodan classic slabs. The VERTEX hold more water. Not sure if this is a good thing! But there $10 cheaper a slab.

 

did you move your drippers when the girls went to the flower room as you may have placed the dripper in a different spot which could cause new rivers away from the main feeder roots , so the plant stresses slightly while it adjusts its root system , this could be the reaction your seeing

<{POST_SNAPBACK}>

 

i placed the drippers in the same general vicinity (which is in the top of the smaller grodan cube which is on top of the slab, an inch or so from the main stem. Seems logical?

 

once again another reason why I like high volume flow and medium frequency with Rockwool once the plants have formed a great root system ,, you do that by running very controlled low volume ( high air ratio ) and low nutes of around 8-12CF for veg and flush them once a week by running your tank for an 1hr or so just before lights out and a nute tank change , then let the slab get very dry , this is what develops roots bigtime and repeat the low volume cycle untill you go to flower , then give it to them , just make sure you are using low nute strengh untill you up the flow volume .

<{POST_SNAPBACK}>

 

 

ok this is what im trying to find out!!! i think im running a controlled low volume but i think it was TOO LOW for the increased wattage. At 1lt in 1 minute per 3 hours in the veg room at 50 watts per sq foot they were so nice and healthy and rapid growing. BUT i dont think that volume is going to cut it at the increase to 90 watts. (ive adjusted to 1lt per hour in 1 minute! = so rapid flow not a dripper system more like a hose!).

 

I run the tank for about 15 mins every 2 days when i add h202 to the nute mix to make sure they get plenty of it when its still active. Also I hand flush the whole slab with 6lts of water per slab once a week just to make sure theres not too much build up around the edge of the river

 

I think i might be running my nutes too high though - 18 to 20 cf in the reservoir during VEG. Maybe I should drop them back to 14 cf??? But i would have thought they would need the increased food at the higher intensity lighting

 

Im aiming to increase the irrigation gradually as they get bigger and start going into flower. I miss the days when i would give em 15mins per 4hrs of 20lts and they grew massive heads with no signs of pyth!

 

SS - im going to take some pics of the room tomorrow when i go there cause i want you guys to critique the set up and see what you think of it!

 

Thanks

Edited February 28, 2006 by keepleft

[F420]

Hi rod good to hear from you. You know your rockwool!

 

Theres not much Rod doesnt know, Hes taught me bloody heaps.

[Roadblock]

Hey thanks for the compliment Ferengi , I,ll get a big head , if I can get some of you guys to think about whats going on in your systems from ouside the square Im happy, I was a lot like Keepleft when I started , my brain was is constantly asking why is it so !

 

Rod