How many cfls

[monkeytail]

I have four forty watt daylight cfls on my seedlings, will this be enough to grow them. 2 feet wide shelf that is 20 inches deep with lights overhead.

 

[Locked]

I have four forty watt daylight cfls on my seedlings, will this be enough to grow them. 2 feet wide shelf that is 20 inches deep with lights overhead.

40 watt equivs or actual 40 watt cfl's? It is all about the lumens and not really about the watts. You need 3000 lumens per sqr foot for the vegetative part of the grow and 5000 lumens sqr foot for the flower part. Those are minimums more lumens more better provided you can ventilate your space and keep temps in check.

 

[monkeytail]

Ya temps are hard?. Im in high temps at 28- 30 celsius with a 50 cfm bathfan for an intake. The air still feels cool to the touch compared to heat from ceramic heaters.

The soil feels cold too , with the high temps. Ive got to get a soil thermometer and check.

Soil temp should be 20 celsius , and 24 celciuse for airtemp?http://www.homedepot.ca/product/42-watt-twister-daylight/917986 6500k 2850 lumens 42 watt =150

 

[Hushpuppy]

You can grow them under that for 2-4weeks but by the 4th week they are going to start stretching for light. If heat is an issue for you then go to one of the online hydro stores (HTGsupply.com, accessdiscounts.com,) several others as well. Order some T5HO lights. You can get either multibulb fixtures or single bulb fixtures. Having those will give you the lumens without all the heat. You can carry those all the way through vegging, and technically all the way through flowering as well but not as good for flowering. For flowering, the HPS works best. Good grow mojo

 

[monkeytail]

You can grow them under that for 2-4weeks but by the 4th week they are going to start stretching for light.

Got my soil thermometer ,soil temp is 25 celsius , air is 28 to 30.

So its 4 weeks in vegetative , and then HPS?

Depending on how they grow, I plan to put them under HPS at 12 "'s

I have a 2 foot flourescent fixture , that I had started with that used two 18 watt bulbs. Could i get two of the t5ho lights and put them in that fixture or , I would need the complete new setup for them other lights?

Besides planting the seedlings in the soil and keeping them under the right lights, temps ,and watered for four weeks, is there any other soil additives or nutrients they need?

 

[The Hemp Goddess]

You need a T5 fixture for T5s. I highly doubt that 2 18W fluoros are going to take you through 4 weeks of veggy growth. You need 3000 lumens per sq ft.

 

[Hushpuppy]

You will need to replace the fixtures with T5 fixtures. I should have said that by week 4 they will be stretching rather than just starting to stretch. If you want to grow nice healthy plants then it is best to have some medium light(like you have now) the first week of seedling growth then ramp up the next week to 3000+ lumens per square foot of lighted space.

You can veg as long as you want. If you intend to switch them at 12" tall then you want to make sure you have good tight internodes(lots of branches between the top and bottom of the plant). Having lots of quality light between week 2 and week(4-6) at flip will ensure that you have tight internodal spacing before switching to HPS for flowering.

As far as nutrients go, You will want to start with neutral soil, not soil that has fertilizers in it already as that will burn the little ones up quickly. You will need to figure out what type of nutrients to use as there are many, and using nutrients are an absolute must for successful grows. You can either go with organic or chemical nutes.

I suggest you read all of the stickies on nutrients and read through some of the grow journals to see some of the different methods the people use for feeding and watering. Those will teach you a lot about what to expect from soil growing, and from different nute brands. Don't use Miracle Grow nutrients as those are way to potent for MJ.

If you have anymore questions, feel free to ask away. We will help any way we can

 

[monkeytail]

If you have anymore questions, feel free to ask away. We will help any way we can

At 2850 lumens per bulb, that would be 11400 lumens with 4 bulbs. At roughly 2x2 foot space =4 sq feet. Or just under 3000 lumens per square foot already. Maby one more CFL bulb?

I'll keep the cooler T5 lights in mind but for now I wanted to consider sliding a sheet of clear plexiglass between the lights and plants , to keep them cooler. Can I use clear plexiglass , without damaging the light spectrum reaching the plants? hxxp://www.homedepot.ca/product/clear-acrylic-sheet-080-inch-x-18-inch-x-24-inch/924840

Hopefully with the right fan placement , that would make them cooler and not hotter. Has anyone any experience with , shielding the plants from hot lights with glass or plexiglass or whatsbest?

When it comes to , having healthy plants to put into flower at 4 weeks I am having a problem. I have been told topping is the only way to , get the most out of a plant. Once I top its another week or two before is growing good again. If I top a second time , its another delay. Unless I am making a mistake here.

If soil is the measure of a good seedling, I could have an issue there too. I'm just a beginner, and am using Walmart miracle grow potting soil for both seedlings and plants, mixed with perlite 50/50. I am not trying to win an award just yet, but I will need the minimum soil requirements.

 

[The Hemp Goddess]

It is not just that the T5s run cooler and spread the light better. They put out a lot more useable light per watt than CFLS. Look at it this way....5 40W CFLs uses 200 watts and will give you a little over 14,000 lumens, while 216W of T5s will give you 20,000 lumens.

Topping is more a training technique. Whether or not you will get more bud is debatable. A longer veg time will give you a larger plant with more budding sites. Ultimately, yield is a function of many factors.

There is good soil information in the stickies. Starting with a good NON-PRENUTED soil mixture is important.

Most people with HPS lighting air cool their lights in the manner you are speaking of. I do not know how well plexiglass holds up to heat or how much it may filter the light. I use tempered glass for all my heat shields. You need a good exhaust fan to pull out hot air and bring in fresh cool air. Your plants need a continual supply of fresh air all the time the lights are on for proper photosynthesis.

 

[monkeytail]

It is not just that the T5s run cooler and spread the light better. They put out a lot more useable light per watt than CFLS. Look at it this way....5 40W CFLs uses 200 watts and will give you a little over 14,000 lumens, while 216W of T5s will give you 20,000 lumens.

.

For now I have over 60.00 of CFL bulbs plus NEW ac sockets in use, and I would need 9 T5 fixtures at 30.00 each . So another 270.00 + shipping +tax

I think they would fit in the cabinet, 9 would need about 12 inches width I guess. That would be nice, I'll remember that but will try to get a goodgrow with CFL.

Again what are the critical temps to keep in check, with seedlings? 24 celsius week 1 -4?

 

[The Hemp Goddess]

No there are far cheaper alternatives--I didn't pay nearly that much for my T5s. And initial cost is only ONE consideration--keep in mind every month when you pay your electricity bill that you could be getting the same amount of lumens for at least 33% less electricity usage. Simply put, CFLs are the most expensive lighting there is to use to grow. They also emit more heat and provide far less yield.

 

[monkeytail]

No there are far cheaper alternatives--I didn't pay nearly that much for my T5s. And initial cost is only ONE consideration--keep in mind every month when you pay your electricity bill that you could be getting the same amount of lumens for at least 33% less electricity usage. Simply put, CFLs are the most expensive lighting there is to use to grow. They also emit more heat and provide far less yield.

Well that price was with a 9 dollar pricedrop, so if you can show where to buy a T5 fixture with a bulb for less than 30.00. I'll be listening!

 

[Roddy]

Why would you need 9 T5's? I'm vegging 12 plants right now under 3. I, of course, am assuming you're talking 9 T5 fixtures...maybe you mean bulbs.

 

[The Hemp Goddess]

Well first of all, I would not be for buying individual 1 bulb fixtures--buy a multi-bulb fixture. Check out HTG Supply. They have some decent priced T5s. But my main point is that you really should be thinking beyond the initial purchase to what it costs to run the lights every month and what you are going to reap 3-4 months down the road when you harvest.

 

[Roddy]

:yeahthat:

 

[Mutt]

0 go to home depot and get a HPS or MH flood light for much cheaper
more light at less watts=more bud for cheaper
CFL's except for veg in small places ain't worth it.

 

[Sol]

If you can fit it, this is what she means.hxxp://www.htgsupply.com/Product-GrowBright-2-Foot-8-Lamp-High-Output-T5-With-Choice-of-Bulbs.asp

If thats' too wide there are smaller ones, including singles.

I happen to be in the market too, so i thought i would share.

 

[Locked]

This is what I dug up online real quick:

These are all on eBay....


T5 HO FLUORESCENT 24 2' 2ft 4 LAMP GROW LIGHT BULBS NEW

Item number: 120686744179 87 bucks shipped.



48" 4ft 4 Tube T5 Grow Light 6500K Bulbs Sun Hydro


Item number: 250855655691 99 bucks shipped

 

[monkeytail]

Why would you need 9 T5's? I'm vegging 12 plants right now under 3. I, of course, am assuming you're talking 9 T5 fixtures...maybe you mean bulbs.

We were comparing the Lumens 2850 per 42 watt cfl and 2000 per T5 bulb.
5 cfls would be 14250 and 8 x 1800 would be 14400.

I had seen the T5 bulbs that were under 2000 lumens.

Half the electricity , unless I then need to pay to heat the cabinet because they are SO COOL!......
and less heat is usually good too!


Nice T5 lights on ebay but i think i'll price lights at a petstore and get a few t5 singles to compliment my cfls and use both types.

 

[The Hemp Goddess]

This is actually the one I was thinking of for your 2' long space. It is 24 x 24 x 3-3/4" and puts out 20,000 lumens.

hXXp://www.htgsupply.com/Product-HTG-Supply-2-Foot-4-Lamp-PL-55-Tek-Lamp.asp

Not all T5 lights are created equal. You want the HO tubes that out about 92 lumens per watt.