Choosing the best bulb

[GreenWolf]

:: SKIP THIS PART, IF YOU WANT THE TL;DR VERSION ::
Hi there. I'm relatively new to this forum, but I've been a long time viewer of many threads, as google indicates this as a good source of info many times.
Until recently I've acquired a couple of seeds (2, to be exact) and managed to germinate them using the paper tower method, followed by the glass of water one. Got 100% germination and the little babies are already both 4 inch tall.
I am keeping them outdoor, in 2 different pots and been making sure they are getting what they need: good sun bath, soil always moist and the occasional liquid fertilizer.
Now I've come across a small, but big, problem.. It is August and I've been told that I should be harvesting by now, not planting.
I wanted to keep things simple, but now I'm seeing myself being forced to go artificial light, to keep the growing progress...
I've done a little research and found a couple products (jesus ****ing christ, the price tab got ALOT lower than I initially saw).
This is what they look like, atm.

:: TL; DR ::
So my question is this: What bulb would you advise me to get? I got a large room to keep it, but NO ventilation other than the all-natural-wind coming through an open door.
Came across these cheap bulbs, but what do you, more experienced growers, have to say?
I have around 160$ to spare, and all the electricity I can use.

 

[Fuzzy Duck]

You going to need to think about better ventilation if growing indoors & more likely exhaust/extraction fan to remove excess heat from the grow area... these bulbs do warm up the area !

Might want to do a test run when you fire up your chosen bulb tho, ideally you want to keep temps under 80F.


Size of bulb & area cover...

600w 4 foot by 4 foot aprox.

1000w 5 foot by 5 foot aprox.

This may depend on reflector design tho which may be perceived as an area most people may over look


In veg stage metal halide or cfl, T5/8 tubes are used these are in the blue light spectrum range aka 6500k, i think MH are around 5500k on average.

Flowering well HPS these are often in the red spectrum 2100k 2050k.

You can get duel spectrum HPS which supports some blue spectrum as well of a large portion of red spectrum & can used for both veg & flowering

 

[GreenWolf]

Hello there, FuzzyDuck!
Thank you for your extensive and detailed reply.
I decided to go with either a 400w setup, or a 600w. I know that I would get most out of it from a 1000w one, but I better start... medium.

I managed to get some ideas on what to get, mostly by searching several products on the internet. After some hours of researching, I came across two brands.
The brand I decided to go with is either iPower or HTGSupply. Both of them seem good, in terms of quality!

I couldn't find the light spectrum specifications for the HPS, but the MH one is 4100k.. Is it too low?
And do you think 2 computer fans would do the job, if pointed directly at the lights? ~2inch away

 

[JuanCarlos]

I would go with a 600w as they are the most efficient HID light. I would look at a duct booster fan on your budget. You are going to be close to the $160, but I think you can fit it in the budget.

 

[Wolpertinger]

Hi Greenwolf,

I might have missed something. You mentioned different size (wattage) bulbs but didnt mention what size ballast you have.
I mean nothing by this, but what ballast do you have?
If you don't, take a look at Apollo on Amazon. You can get a 400 or 600 watt set up for under $200. Not the best, but economical..

I started with a 400 then a 600. Later I added 3 600 Phantom IIs and I do like those alot better. Just purchased a Mars 1200 with tent and have 2 platinum 300 LEDs which earn their keep quite well. This has taken 18 months to acquire so I can feel the pinch in the wallet when making decisions as well.

It has been an interesting journey, and Kudos to the pioneers on this board. I have learned alot here and in our local hydro shop as well

 

[Fuzzy Duck]

Mmm small computer fans are more likely not going to cut the ice...

You may need some thing like this

Inline fans need to be of suitable size roughly to be able to exchange the grow room air 20 times per hour (aprox)

I work on a passive intake vent & active exhaust other people may use active intake/exhaust on a negative pressure basis to keep the smell in the tent & let the carbon filter do its job.

You need to work out grow room volume W x D x H x 20 & this will roughly give you an idea of fan size needed (metric calculation btw) you could use one large fan or 2 smaller fans to do air exchange & volumes required, more likely best to use a slightly larger fan than needed tho... Oh ye this all warm air needs to be extracted from the grow room aka exhaust !


Back to lighting...

Mmm well ye some people think big is best 1000w is really not that great to be honest when one starts to look at umol, par etc & the inverse square law of light effect (hanging distance) !

600w pretty much meets the sweet spot tho with in given terms & a rather large area to discuss !


MH 4100k well they have been kicking about for donkeys years K / kelvin may range a little between brands if it says it MH on the label it will do the job for vegging... but MH may be viewed as some what old school by some growers.

When cfl or T5/8 tubes can produce equal results for veg at lower wattage than MH = lower electric bill, it is some thing worth looking at tho.

 

[GreenWolf]

@juan 600w? I do what to start with a few plants (only 2 atm) and take it from there.. Would the difference between a 400 and 600 be that much of a deal? And yes, I want a generally good yield and quality..

@wolf I dont know the size of the ballast.. But hey, here's the link!

@FuzzyDuck wow that seems a pretty sweet system.. Expensive looking too! I'll be looking into that once I get a more solid budget. Is it too hard to DYI?
t5/8 tubes seem good. But will it be ok if I hang on to mh/hps? will it affect production whatsoever?

 

[Fuzzy Duck]

Ye MH & HPS will be fine it works at the end of the day it's hardly going to effect production...

DIY can be pretty cheap depends on if you want to make a grow box or convert a room but a lot of choice's to think about !


I would be concerned about environmental issues such as temperature & RH aka relative humidity control tho in the long run for growing indoors.


When i first started out the grow tent kit cost me about £350 that was tent, fan, ballast 400w, Hps 400w, 125w cfl & leads/cable, reflector/hood, pots, 50 L bag of compost plus nutrients all included, the tent size was 90cm by 90cm by 180cm.

The first grow i used regular seeds & only got two female plants both produced slight over an oZ each which virtual covered the cost of the kit, 2nd grow i was saving money as it is cheap to grow your own

Made some minor tweaks on kit since then like a better reflector/hood, slightly better inline fan & oscillating fan.

 

[JuanCarlos]

Yes, for the little bit of money you are going to save, the difference between a 400 watt and 600 watt is a big deal in my opinion. You may be starting out with two plants, but if you decide to continue growing a 600 watt setup will light up a 4x4 grow tent nicely. A 400 watt will come up short unless you grow in a 3x3.

If you read Ed Rosenthal's Marijuana Grower's Handbook he talks about recommended light per square foot, which will increase quality and yield. According to him the 400 watt light would be ok for a grow area of about 4x2.

What others have mentioned is important as well, which is your ability to deal with heat in your space. Forget about computer fans. At a minimum look at duct booster fans.

Good luck to you. Might be worth grabbing some good reading material or sifting through the site's helpful FAQ section. How to Grow Cannabis - Everything You Need to Know!