yellow spots. pics

[italian04]

yellow spots. a couple weeks old and have gotten a little worse. nutes at about 1/2 strength. ph=5.6 plants are 5 weeks and a day old. temps are high...around 90 during the day and 74 at night. running a 1000w hps with exhaust fan and portable a/c in room. need help. thanks in advance.

italian04 Reviewed by italian04 on 07-02-2008. yellow spots. pics yellow spots. a couple weeks old and have gotten a little worse. nutes at about 1/2 strength. ph=5.6 plants are 5 weeks and a day old. temps are high...around 90 during the day and 74 at night. running a 1000w hps with exhaust fan and portable a/c in room. need help. thanks in advance. Rating: 5

[stinkyattic]

Try to get your temps down. The leaf edges are curling up and that means your plants are uncomfortably hot.

[italian04]

ya thats the prob. im tryin to find a decently priced 400w hps but until then they r gonna have to use sum sunscreen so you think the heat is a reason for the yellow spots?? i just got my feminized seeds in the mail so im about to flower these females to be (hopefully). i know its early but id rather flower early and see what sex they are, than to leave them vegging and they turn out to be males. thanks so much stinky. ive read so many of your posts in the past two months its ridiculous. so do you think those plants look pretty healthy??

[stinkyattic]

Overall yeah. They look good. Instead of a HPS400, why don't you switch to an air-cooled hood, and get the ballast out of the room if you haven't already. As comparison, I've got 2000w in a 6x6x6 cube with air cooled hoods. You can get a lot of light in a little space if you run a high CFM blower, at least 200CFM, cooling your lights and exhausting that air out.

[italian04]

i think my hood is air cooled. All i have is an exhaust fan that sucks there hot air from the light and blows it out of the room. im not sure if thats a blower or what. im still a newb on that kinda stuff. what about the yellow spots? should i not worry about that right now

[stinkyattic]

Check the pH of your medium (runoff; there's a sticky in problems about it that applies to dirt but has explanations) and make sure it's correct- 5.8-6.2 for hydro, 6.2-6.6 for soilless, 6.5-6.8 for dirt. That's important, and so is making sure that your medium isn't holding undesirable fertilizer residues.

But the heat will make all that stuff worse.

Can you get a picture of your hood and exhaust system? I have to step away from the 'pooter for a bit, but if you post up the setup, we can try to make it work more efficiently, and that could end up saving $$ in a/c too. Woo hoo!

[italian04]

im doing DWC. 2 gallon buckets with airstone in each. they sprouted in coconut fiber plugs which were placed in ph ready hydroton. the buckets stay at pH 5.6-5.8 check twice daily. there really is no ph runoff. im using 1/2 strength nutes right now. ive heard that gh 3part lack magnesium and to add a tsp epson salt but im scared to try it. im goin outta town tomorrow night so i dont wanna do anything that might fuckem up more while im gone. thanks for all your help :thumbsup: in thie pics...the ballast is kinda wac but i got it off craiglist pretty cheap. works fine. doesnt really put off too much heat. the blower (i guess it is) sucks air from the hood and blows it outside the room. im not sure if thats how it is suppose to work but its doin pretty good. and with all that the room heats up pretty good. when the a/c is on is goes down to 84-90 humidty at 45-55. night time temp is 76

[stinkyattic]

Okey dokey I already see some things that could be tweaked.
First let's talk Magnesium. I don't know about the GH 3-part and its Mg problems, but I would hesitate to add Epsom salts to your res!!! You're right, that is kinda eek. If you like epsom salts as a means of Mg delivery, make a spray bottle up with 1/4 -1/2 teaspoon, a quart of water, and a drop of liquid dish soap, that you can lightly mist onto the leaves if you see Mg def signs, whcih look like distinct pale stripes between the veins. Not bright tan dead stripes though; that's something different. CalMAg Plus is also GREAT and if you look at the sticky in hydro called 'Latewood's Legacy', there is a great discussion of the GH 3 part as a grow tool.

Next your ballast! If you can get it up on a milk crate or at least a little off the floor, awesome. If you can put it OUTSIDE the grow area, awesomer. Ballasts give off a lot of heat.

The hood! Yup it is air cooled. So is the other end- the one we can't see in the pic- is that open to the room, or is your light on its own closed circuit and not exchanging air with the plants? Is there any way to make the curves in your ductwork smoother, or even straight? Turbulence within a duct will definitely cut into your total air flow! Do you know the CFM rating on your fan, and where is it in relation to the light, and to the exhaust ducting? A strong fan (100-300cfm) that is set to suck air through your exhaust is a must with a big light in a small space.

Gotta run, will check back later.

[italian04]

no it is open to the room. i just moved the ballast outside of the room. that light just gives off so much heat. the blower i have is pretty dam powerful. its definitly blowing hot air out of the room. im really not sure what else to do except get a small wattage light. and on the calmag ive been reading that u only need that with ro or distilled water. im using tap at about 120 ppm. im gonna make that spray you were talking about. and try it out. i guess ill just have to see if the plants flower well at this temp. they have been growing excellent so far so hopefully they keep it up.

[jnewell33]

from your picture it looks like the portable air conditioner is blasting away on your girls. I think that is the main the problem and if your temps stay at 90' during the whole flowering you are lucky they look so as good as they do. The portable ac will also lower humidity levels as well. Check the roots as well. Soggy plants sag.