Need Help 400 watt mh light adjustment.

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purplepride

Well-Known Member
I am on my first indoor grow. I started out with a 400 watt mh air cooled hood in my tent. I have a fan circulating over plants and another fan pulling air through my sealed hood to outside my tent. Temps have been from 72 morning - 80 degrees during hotest part of the day. I started out with the plants about 18 inches from the bulb when they broke through the soil. I lowered it down little by little through the last 4 days and today is day 5. They stretched out to about 2 inches around day 2-3. I have gotten the light down slowly to about 12 inches from bulb to the tops of the plants and they are working on there 2nd pair of leaves this morning. My question is. Is it normal for the light to be this far away. I know its 400 Watt MH but even 12 inches seems far away. How do I know where the sweet spot is? I dont want them to stretch anymore but I dont want to burn them either. Please any serious or knowledgable advice would be appreciated. Thanks

-PurplePride
 
Hey,are you cooling the light through ducting? Do you have that ability? When working with air cooled hoods sometimes they can be iffy I like using tubes because I can latterly stick them 6 inches away with ducting, if you are running ducting then you can get them close, with seedlings though u gotta be careful they really don't need that much light I put a 45 watt Flo over my dome for a couple weeks then set them under the mh
 
yes I am running fan and ducting through my air cooled hood. And i have a air king clip on fan circulating air in tent. Sorry for posting in so many forums. I am new and just trying to get multiple responses because I dont wanna mess it up bad my first time.
 
If u are cooling with ducting your fine, your babies will let you know when they don't like the light..all I can say is keep the hood cool and don't worry about your grow, they are like children they let you know when they are hungry, hot, sick etc...if you don't see signs, then don't worry to much
 
Two out of the 5 girls have little crinkles or something going on with the first two single leaves. The other 3 girls the leaves look perky. Just how they should.
 
purplepride said:
I am on my first indoor grow. I started out with a 400 watt mh air cooled hood in my tent. I have a fan circulating over plants and another fan pulling air through my sealed hood to outside my tent. Temps have been from 72 morning - 80 degrees during hotest part of the day. I started out with the plants about 18 inches from the bulb when they broke through the soil. I lowered it down little by little through the last 4 days and today is day 5. They stretched out to about 2 inches around day 2-3. I have gotten the light down slowly to about 12 inches from bulb to the tops of the plants and they are working on there 2nd pair of leaves this morning. My question is. Is it normal for the light to be this far away. I know its 400 Watt MH but even 12 inches seems far away. How do I know where the sweet spot is? I dont want them to stretch anymore but I dont want to burn them either. Please any serious or knowledgable advice would be appreciated. Thanks

-PurplePride
Click to expand...

why would you post this same post four times in a row, within 7 minutes?...as such I'll consider it as spam
 
Why would you waste your time posting that on my this thread if you dont want to help a new person out??? I said on other threads. I'm Sorry I was trying to get multiple responses and or input so I can make a more educated decision on setting my light. If you dont want to help thats fine. But realize I am human and I did not realize people were going to get that bent out of shape about it. Rookie Mistake. I dont even know how to delete the extra ones. Thats how new I am so if you care to let bye-gone's be by-gone's feel free to help me out. Otherwise Good Day. Thanks
 
Your footprint for that 400watter will be about 28x28 inches max and your optimal grow zone is from 4 inches(vented,8" non vented) from the light down to 30 inches. Young girls can not take the intensity so starting at 12-15 and slowly dropping the light to its final position when your girls reach maturity. JAS
 
JonnyAppleSeed420 said:
Your footprint for that 400watter will be about 28x28 inches max and your optimal grow zone is from 4 inches(vented,8" non vented) from the light down to 30 inches. Young girls can not take the intensity so starting at 12-15 and slowly dropping the light to its final position when your girls reach maturity. JAS
Click to expand...

Thank you, I finally got some straight up advice.. Not too worried about footprint at this time cuz I started them in plastic cups so they are pretty close together till I re-pot them. So I decided to dim my ballast down to 360 and the light is 12 in. from the top of the plants for now. Right before I switch to flower I will be running 600 HPS instead. Only running the MH for Veg. Optimal grow zone is 4 inches for vented, 8 inches for un-vented. And just so were clear what do you mean by down to 30 in? That seems like a long ways for a light to be away, or maybe i read that part wrong?
 
purplepride said:
Why would you waste your time posting that on my this thread if you dont want to help a new person out??? I said on other threads. I'm Sorry I was trying to get multiple responses and or input so I can make a more educated decision on setting my light. If you dont want to help thats fine. But realize I am human and I did not realize people were going to get that bent out of shape about it. Rookie Mistake. I dont even know how to delete the extra ones. Thats how new I am so if you care to let bye-gone's be by-gone's feel free to help me out. Otherwise Good Day. Thanks
Click to expand...
rookie mistake my ass....spamming 4 times in a row is not an accident....BTW I would not consider someone who has been around since March 2012 as a rookie

anyhow, I'm wasting my time on your stupidity because I want you to understand how fucked it is to post 4 times....so beyond this post you won't hear dick shit from me unless you are stupid enough to reply to this
 
Indoor Sun King said:
rookie mistake my ass....spamming 4 times in a row is not an accident....BTW I would not consider someone who has been around since March 2012 as a rookie

anyhow, I'm wasting my time on your stupidity because I want you to understand how fucked it is to post 4 times....so beyond this post you won't hear dick shit from me unless you are stupid enough to reply to this
Click to expand...

First of all this is my first indoor grow so I meant rookie to that specifically. Second I Joined RIU so that I could get advice on outdoor last year. Things are not always as they seem and I never said it was an accident. I posted it to 4 different areas hoping to get a lot of input. Not knowing people like you would be so sensitive and freak out because "OMG" I posted the same thing to more than one area of a site to try and get a bunch of advice. Oh and it seems as if it actually worked because out of all of those only one person actually gave me straight advice. So for what its worth stop freaking out. We are only human and I wont post things more than once again. Peace
 
purplepride said:
Thank you, I finally got some straight up advice.. Not too worried about footprint at this time cuz I started them in plastic cups so they are pretty close together till I re-pot them. So I decided to dim my ballast down to 360 and the light is 12 in. from the top of the plants for now. Right before I switch to flower I will be running 600 HPS instead. Only running the MH for Veg. Optimal grow zone is 4 inches for vented, 8 inches for un-vented. And just so were clear what do you mean by down to 30 in? That seems like a long ways for a light to be away, or maybe i read that part wrong?
Click to expand...
You will damage your bulb running it like that. Just raise the light and keep it on 600. These dimmable ballasts are questionable in my books. Approx. 36 inches down is where the intensity drops right off, your right its not as intense as 15 inches from the light but you will produce hard buds that far away, removing these lower branches in this zone will result in a yield drop, so be careful. If you keep growth within these perimeters you will get the most out of you plants. JAS
 
Thanks for the advice. It is a 400 watt mh bulb though so I dont want to set it at 600. Right now i've still been keeping the light around a foot from tops and it seems to be fine for now. There is a ton of new growth and I have never seen anything grow this fast. 1 week old today and they are taking off like rockets with no yellowing. The next day or so I will already have branches. After veg I will be moving the light up a bit and switching to my 600 hps. Not sure how far away that should be either but my air-cooled hood stays ice cold with my ventilation so probably closer than most would think.
 
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