Square feet and Watts.............?

[puff4twentynow]

What is the amount of watts you want to have per square foot?

Example Question: Is one 400w HPS enough to grow two plants within 4 sq ft.?

[Zandor]

The magic number is 50 watts per sqft. More light equals more buds and light from the top and light on all sides will grow more bud then just one light above. The problem with top only lighting is penetration to the lower branches. With top lighting only you will only get bud from the top 1/3 to 1/2 of the plant.

Yes 400w is fine for 2 plants. Use Mylar on your walls to increase the light to the lower branches it does help.

[puff4twentynow]

how many grams per watt should grow with 400w HPS for 4 sq ft @ two plants flowering for 60 days?

Can anyone answer that?????

[llamaman666]

Depends on veg, strain and all sorts of other variables. if you veg like 30 days it would be something around 3.5 ounces a plant. that is a little under 100 grams

[BILL THICK]

The magic number is 50 watts per sqft. More light equals more buds and light from the top and light on all sides will grow more bud then just one light above. The problem with top only lighting is penetration to the lower branches. With top lighting only you will only get bud from the top 1/3 to 1/2 of the plant.

Yes 400w is fine for 2 plants. Use Mylar on your walls to increase the light to the lower branches it does help.
Maybe you can help me decide on some lighting connsidering the factors
120 square foot room I was planning 1000 watt MH and 1000 watt hps from what you just explained would I do better breaking them down into several smaller watt lamps ? What might you suggest the best lighting arrangement ? thanks Bill Thick

[Zandor]

Bill
Light requirements can change with how you grow and your budget. I would be happy to help you but I need to know how are going to grow, the room size and height?

Will you be growing with soil or go hydro? If you are choosing hydro what method are you using?

How about budget?

Last what yield would you like to achieve?

In truth it takes about 3 grows before the equipment is paid off so budget for that. Saying you can upgrade later is one thing but you need a good base foundation to start. Good light, good nutrients, good air flow, cool temperatures, and a controlled environment.

[BILL THICK]

Bill
Light requirements can change with how you grow and your budget. I would be happy to help you but I need to know how are going to grow, the room size and height?

Will you be growing with soil or go hydro? If you are choosing hydro what method are you using?

How about budget?

Last what yield would you like to achieve?

In truth it takes about 3 grows before the equipment is paid off so budget for that. Saying you can upgrade later is one thing but you need a good base foundation to start. Good light, good nutrients, good air flow, cool temperatures, and a controlled environment.
Thanks for the response Zandor. I have a 10 ft X 12 ft room with an 8' ceiling(insulated attic above that). I am directing my efforts towards hydro, ebb and flow. Budget is not a major strain at present although could become one shortly down the road, but I prefer making every effort to produce a favorable harvest on the first crop, (however impractical it may be for my first grow-lol). Therefore I feel I would best be served by getting the proper equipment and necessary tools and nutrients.
My initial supposition leaves me considering 2 1000 watt high intensity light systems (1- mh 1 hps). But as I continue to absorb information and read opinions of those who are experienced I am leaning now to thinking I may want to break these into more lights with less wattage. thus I come to the point of asking your advice.
Also curious about distance(spacing) between plants . Any time and effort you may afford me would be highly appreaciated . peace

[rapid88]

Another way to have light reach all of your plant is to tie them down, as this exposes all the branches to equal light.

[Zandor]

What yield are you looking for? How much dry buds do want to grow for your needs?

If you want an easy start into Hydro Aeroponics or drippers are about as easy as it gets. You can build most of the equipment yourself.

So what is the number of plants or how many dry buds (total weight) do you want to grow?

[Beeblebrox.420]

The magic number is 50 watts per sqft
Disagree slightly. The number of watts per unit area will depend on the type of lighting, its efficiency and watts drawn per lamp. You want to shoot for about 10-15,000 lumens per square foot, which approximates typical direct summer sunlight. Lumens are more important than watts when it comes to grow lighting. Bear in mind that the lumes per watt figure for a given lamp will increase with higher wattages - in other words, the higher the wattage of a given lamp, the more efficient it generally is. I give typical lumens per watt figures for some common lighting types below, in order of efficiency:

Incandescent: 10-20 lum/w
Fluorescent: 35-100 lum/w
Metal halide: 80-120 lum/w
HPS: 90-150 lum/w

[eastwestconnect]

I got a question for you guys. In a room 7x7, do you think that a 1000w mh and four fluoros is good enough light, or do you think that I can get rid of the fluoros. I have them going right now and they are going good, but are 4 floros needed. Some info. for whoever answers I'm growing organic, and hopefully I can get enough to get my money back and have some chronic to smoke to tha head. One problem is the heat if I dont run the AC, it gets up too 100 degrees, 75% humidity because I am trying to keep it all in the room with no exhaust out. Is it possible or do I have to cut a hole in the ceiling and exhaust it up there. Any suggestions are more than welcome.

[puff4twentynow]

Ok. So the more lumens you have for your girls, the better yield right? I have 90,000 lumens shining down on four girls in a space of 8 sq ft. How much bud do you think i will get????

[BILL THICK]

would it not depend on what number of lights you had and what each lights wattage was?90,000 Lumens if from one light would be equivelant to one 600 watt hps light and would be about 4218 footcandles,you could get approx. 87,000 lumens using a 250 watt and a 400 watt hps but the foot candles total from those two lights would be about 3613 footcandles and the yield would be considerably smaller. All this not taking into considertation the diminishing of light at each square foot the lights are from the plants. if the light(s) were one 600 watt the girls would not be getting the full 90,000 lumens . since you said they were I would have to assume you were running 1 - 1000 watt hps if that were the case I would guestimate about 5 pounds. one 600 watt about 2 lbs
I am most likely off due to the intensity of of light decreasings as the distance from the light increases . I hope I am getting closer to the idea anyway .
thanks Bill

[puff4twentynow]

No it is not one 1000w bulb. I am running two 400w HPS @45,000 lumens each. This is my setup...........

Do you really think i will get more than one Lb?? :)

[Zandor]

See what you did Beeâ?¦..? You got everybody confusedâ?¦lol. Yes you are almost correct but I saw no reason to bring in the calculations for luminance VS watts VS PAR watts. The watts per sqft is a rule of thumb and not the best way to calculate useable light and does not take into account the height of the bulbs and only works for HIDâ??s. The conversation started out about HID so I just kept it there and made it simple. Calculating foot â??candles or lux is a more accurate way to estimate the amount of light plants receive. This still does not really measure the amount of light the plant uses. For calculations purposes I use 10,000 lumens and the formula I=L/D². You know how I grow so that even does not apply but itâ??s a fair rule for 95% of the people out there. But in a literal terms you are correct I did quote a rule of thumb.

Eastwestconnect â?? I just took down a 7x7x7 room and it had 9000w of HPS light all in cool tubes & 3 light movers. Your temperature is way to high. I ran one 10,000 BTU window unit AC to keep my room no hotter then 79f and I added humidity to bring it up to 80% during veg and then down to 50% until the last 3 weeks of flower when I take it down to 35-40%. I use ½ of my lights as sidelights not top lights. The increase of yield production is all in controlling the environment, using supplement CO² , and increasing light to all the branches, top, side and lower with direct light and not just reflective light.

Puff4twentynow â??On offence meant but, no you will be luck to get 4 ounces of dry bud from what I can see right now. Iâ??m just guessing but you donâ??t have glass hoods on your lights do you? Is that aluminum foil you are using on your walls and hood? What is the average temperature under those lights? Do you monitor it regulary?

[Beeblebrox.420]

Right you are, Z. I just wanted to provide a rough conversion table for people who aren't using HIDs. People might see your 50 W/ft^2 and assume that was true for all lighting types. It also doesn't apply linearly if you're using significantly higher or lower watage bulbs than the average (I assume the 50 W rule is based on a 400 W bulb average?) But, you know that, too. :D

[puff4twentynow]

Well i guess we will just have to wait and see what my yield will be......Here some pics........ 3rd day into flowering.......... :D

[BILL THICK]

Zandor with that many lights in a 7 x 7 x 7room was there a significant increase in quantity and/or quality to warrant that ammount of light? how many girls did you have in that space? I am still struggling with plant spacing and determining the best lighting arangement and with which lights.

How much heat do these HPS lights put out?!?

My Growroom is 10L x 12w x 8h + a large closet. The closet for holding my water resevoir(have 2 50gal drums), control unit(ebb and flow system) and starts and/ or clones. I have turned what was once the ceiling fan into a circular light mover that will hold,I (still undecided)tentatively am thinking of two 1000watt HPS lights with reflectors or maybe one MH 1000 w and one HPS 1000 w. walls will be covered with reflective mylar. have ventilation fan and input fan . Would flourescent lights or smaller HPS lights work for the side lighting?
Not really planning on crop rotation and if I do and need a vegetative staging area I have other area available so I started out thinking of trying 36 plants .... that was lowered down to 24 and am now giving consideration to only having 18 but then again there is the undecided factor of lighting and reasonable amount of spacing between plants.?

Can I get some input on my situation, any help advice or suggestions will be greatly appreciated. I have been doing so much reading and not being overly intelligent type trying to absorb everythng has just about left me brain dead. HELP!
Thanks
Bill

[Zandor]

Bill you don't want to start growing Hydro in a room like mine. It's not for the novice but I finished with 6 plants in KBS in that room. It was just less than 12 pounds this time dry. The new room at the new house will be larger so I can grow up to 12 plants in flower.


I use cool tubes and 10,000 BTU AC window type unit so my temperatures were no hotter then 78 and no lower then 70 for the whole flower period. With cool tubes you can get the light close with out burning your plants. The pictures in my gallery are from another grow, but it had 3 tons of AC with it too so no cool tubes.

Lets see Bob what yield are you looking for in the end. Thatâ??s really the question to ask. 10 x 12 is a big room for over 90% of the people who grow here for personal use. If you want to grow for a living that cool with me I donâ??t care personally the more the merrier I always say. Iâ??m a designated medical grower for several users here in CA and I donâ??t need to sell any myself. I just hated buying the crap that is on the street at those prices for my friends.

If you need would like help in designing a system to fit your needs I would be happy to help you. Do you have any pictures of the area so we can have before and after pictures?

The problem with light movers is not being able to cool the bulbs; you cool the room. But if you are good with tools then you should be able to do both. My preference is for cool tubes only because you can get them closer then any other HID light hood.

Rotation of your crop is a must if you want to get in more then a few grows a year. Buy with the size room you have I see no reason why not. Ebb & flow tables are fine but they are not the best or even the easiest by far either. Ebb & flow table make as much trouble as they save and if you use rock wool you are looking for problems

Drippers are easy, grow quick and cheep to build.

Aeroponics is probably the easiest thing to learn but they too have their problems. They are just a wet version of ebb & flow tables to me. Yes they are different methods but if you think about it the principle is the same and itâ??s limiting by design. Flexibility is not an option with either method.

[BILL THICK]

wow, each time I get close to deciding which method to use I find myself confused again. Yes Zandor I could certainly use your help and advice. I have read your post and you are obviously an accomplised technician. I would feel privledged to get your assistance.
I am not using the ebb and flow table I have gathered two 50 gallon plastic drums, made a control unit and have 5 gallon buckets with plant containers for inserts all to be gravity fed by control unit. I have removed the rug and have a cement floor in the 10' x 12' room which has a 3' x 12' closet. I have an exhaust and input fan set up[ , other than those the room is sealed . I have two window type air conditioners at my disposal. I have a few water pumps to use but not sure the gph capacity I will need. I had planned on using rockwool and hydroton grow rocks fro grwing medium but am open to suggestions on the grow medium to use. As far as that goes I am open to any suggestions as what to use even if it means scraping what I have already. I am still undecided on light set up although I had tentalively thought about (2) 1000w HPS on circular light mover but am now faced with distance of light from plants from lights and cooling of bulbs. considered lower watt hps for side lights. i have on my list to buy flora nutrient(3 part),cloning gel,mylar to cover all walls,general hydro ph+ and ph- and oakatron double electrode ph tester, and co2 test kit. I have given thought but not determined the necessary odor and security precautions that will be necessary. the ammount I wish to harvest is as much as possible although I do not intend to sell it . I am only going to be able to dio this for less than a year and that will be stretching it . my brother is paralyzed and I am trying to get him home once he is here there will be outside visitors here on a routine basis and growing will be not practical.
just out of curiosity what is entailed in getting a license to legally grow for medical purposes in cali?
not sure what what kbs means?
are drippers grown in soil or grow medium? what do you think is the best type of system for me to use?
I don't have any pictures of the room as it is now empty but I will take some for sure.
your advice on how to design and make use of the space I have will be of great assistance to me. I have done alot of reading but realize nothing can substitute for experience. I'm not a lazy person and will take whatever steps necessary to make this experience as practically useful as possible. I think its very commendable that you take the time to help those who need the advice of experience to assist them. I apprecite your time.
talk about rambling on , I better stop before I start to mumble.
Thanks alot
Bill

[Zandor]

That's enough to work with bill. If you live in CA I would not worry about other medical people visiting. Active Coal filters and ozone generators will take care of all the odor problems. Check back with me in a few day's I'll work up a design possibility for you and then we can go from there.

[BILL THICK]

Thanks Zandor, totally cool

[del...]

zandor...or we could do a photo-shoot of setting up a new hydro room grow for a perpetual garden...eh? if you can get to the vegas area i can supply the equipment and room then we document everything from the initial set up into vegging...

[email protected]

[Zandor]

Del.. contact member Garden Known I think he want's to do just that. I think we can work something out buddy. Vegas is only 1/2 day's drive from here.

[BILL THICK]

Zandor, hello waiting to hear from you,.... not rushing you just wanted to let you know I am still interested. Looking forward to your postings
Thanks and have a good day,
Bill

[HARDDON]

Zandor is probably busy climbing his trees. You have to yell harder for him to hear you.

He's prolly 20 feet in the air up there in the canopy of his rain forest.

[Zandor]

Bill....I will get you something this weekend. It's been a ruff week (heath wise) but I will come through for you.

[BILL THICK]

Thanks Zandor hey if your busy and not feeling well it can wait. I appreciate the help but a couple days is not going to make any difference if your not feeling well.
Say do you really have a canopy rain forrest ?
lol
I'll keep an eye out for your post. Be well
Bill

[puff4twentynow]

adsf

[BILL THICK]

Zandor are you still feeling poorly or what.....waiting to hear from you , please
thanks
Bill

[BILL THICK]

WHATS UP ???? IF YOU DIDN'T INTEND TO HELP WHY NOT SAY SOMETHING INSTEAD OF LEAVING ME HANGING

[Zandor]

You're right Bill, I'm sorry. This treatment is leaving me with less engenery then I thought. I'm reading over what I have for you now.

just out of curiosity what is entailed in getting a license to legally grow for medical purposes in cali?

I'm in SoCal and it's really easy.

not sure what what kbs means?
Killer Bucket System, it's how you grow trees.

are drippers grown in soil or grow medium? what do you think is the best type of system for me to use?
No drippers are used with grow rocks to top feed the plants. You can run drippers 24/7

Do not use rock wool save yourself some headache

You have about everything right only some controllers to make your life easer. You will need a fogger to keep up the RH using an A/C system.

How many plants do you want to grow?

lets set up a time in chat to handle the details quicker that way if you don't mind.

[BILL THICK]

sounds great to me Zandor you tell me what timne to go to chat and I will be there . what does one have to do to grow legally? talk to you in chat let me know and hey..... ty Zandor
bill

[Zandor]

5-13 about 9 am PST work for you?

[BILL THICK]

I WILL MAKE IT WORK FOR ME . THANKS I'LL BE HERE AT 9 AM PST 5-13
BILL