Does flowering under CFLs take longer?

[Man1fesT]

I am 7 weeks into flowering using CFLs and this strain is supposed to take 6-8 weeks, however the ladies don't appear (to the naked eye) to be anywhere near being done.

I am wondering, does it takes longer for the flower phase to complete under CFLs than it does under an HPS or the Sun?
Does the estimated "6-8" week flowering account for any usable type of light? Or a specific light?

Thanks.

Man1fesT Reviewed by Man1fesT on 07-26-2009. Does flowering under CFLs take longer? I am 7 weeks into flowering using CFLs and this strain is supposed to take 6-8 weeks, however the ladies don't appear (to the naked eye) to be anywhere near being done. I am wondering, does it takes longer for the flower phase to complete under CFLs than it does under an HPS or the Sun? Does the estimated "6-8" week flowering account for any usable type of light? Or a specific light? Thanks. Rating: 5

[Man1fesT]

...Anyone?

[spfcm17]

I am also curious to see the answer to this question, as I haven't noticed (I could be blind) any threads that tell you to switch lighting, or that any lighting is necessarily better than others.

[crabbyback]

I don't use CFLs myself, but I don't remember reading that things take longer to finish under them.

There are numerous things that could make your plants go longer than you think they should. And, even in stable genetics, individual plants are just that, individuals.

So, maybe if you posted a picture and some information about the plant(s), someone could make a diagnosis?

[Italiano715]

Factors including long time finishers are:

1. Heat
2. How much lighting
3. How close the lights are
4. PH going in and out
5. Feeding schedule (how often give nutes)
6. Type of CFL lights
7. How many CFL light (lumen output)
8. and so on and so forth

You can't just base that a paper says it takes 6-8 weeks and go by that, because like above there are tons of factors that make a plant take longer and depending on how bad the situation it may not even get bigger, it may just mature rather than fill in. Heat will do that especially if not tended to correctly!

[Man1fesT]

I know many different factors can have an impact on the outcome of your crop but hypothetically, if two different crops with virtually identical environments except one has a 400w HPS and the other has equal wattage of CFL's, would the crop under the CFL's take longer to mature?

[BlewBerry]

I dont think that light will effect your flowering time...every other factor it will though. i.e. potency, taste, yield

[Italiano715]

I know many different factors can have an impact on the outcome of your crop but hypothetically, if two different crops with virtually identical environments except one has a 400w HPS and the other has equal wattage of CFL's, would the crop under the CFL's take longer to mature?

When using CFL's it doesn't have the same lumen output as a HPS, so you would virtually have to use more wattage from the CFL's.

Basically 250W of CFLs is not the same as 250W HPS...The HPS has a lot more lumen output then the CFLs, plus the HPS penetrates further into the canopy usually resulting in bigger buds, I.E. all other conditions are met.

[nomadinexile]

Lumen output is only part of the story. Is the hps air cooled? That glass takes out 10%+. Do you have your one light 3 feet above the highest part of your unkept canopy? (I Don't mean you, just hypothetical )
You get were I am going though right? I think equal would come out fairly equal if you do a banging job!

To the original poster: If you have everything dialed in, and are efficiently using 10000 lumens per square foot, you shouldn't have a longer harvest period. That would assume shorties or SCROG though. Otherwise, the plant will get weird if you let them get very tall or very far away from bulb.
2"-4" max. Oh, that's a lot of Cfl's per square foot though. 7 23 watters of the "bright white" I just saw would be 105000 lumens. That's a lot of bulbs in a small spot. So realistically, you will probably use less, and it will take a little longer. But with time, ingenuity, and good venting, you could do it. imo

When using CFL's it doesn't have the same lumen output as a HPS, so you would virtually have to use more wattage from the CFL's.

Basically 250W of CFLs is not the same as 250W HPS...The HPS has a lot more lumen output then the CFLs, plus the HPS penetrates further into the canopy usually resulting in bigger buds, I.E. all other conditions are met.

[MonkeyBone]

On my previous grow I had 18-20 light bulbs (CFL) that produced about 30 000 lumens on 2 plants. Took 3 months of flowering.