4 4ft T5s versus 400w CMH

[pinecone]

I have a grow cab with a 400w switchable that I'm running a Phillips CMH in. I've always managed to veg plants pretty long (2 months) under the MH or CMH light and keep them pretty short and bushy with some training. I've never had a plant that finished above 2ft, but I've never grown a real stretcher. Probably the biggest stretcher I've grown has been C99 or Reeferman's Red Congolese. Both these were vegged a long time and finished under 2ft.

Recently I purchased a 4 bulb 4ft T5 lamp to start my tomatoes and peppers for my outdoor garden. I would also like the use the T5s to root clones and veg MJ plants.

I currently have a cab full of quick finishing plants (Chimera C4) that are going into flower this week. For my next grow I'm planning on growing some stretchier plants (SSH, Kali Mist, Dutch Dragon, and Island Sweet Skunk (fed)) that I would like to keep shorter and bushier (all relative) and I'm wondering if it is going to be possible to keep them as compact under the T5s as they would be under the 400w CMH light. If I don't want them to stretch too much when should I start them under the T5s (now, 3 weeks prior to finishing my current crop, or somewhere in between?).

Any assistance you could offer would be greatly appreciated.

Pine

 

[Aerohead]

Maybe if you had the 8 bulb 4' fixture but I'm pretty sure 216 watts of T5 won't compare to 400 watts of CMH.

 

[pinecone]

Maybe if you had the 8 bulb 4' fixture but I'm pretty sure 216 watts of T5 won't compare to 400 watts of CMH.

Yeah, I'm pretty sure they can't compare and full size plants, but the differences might not be noticeable on a 1-month old plant with some training?

I guess what I'm asking is when does the difference in light power become an issue.

Pine

 

[Aerohead]

I believe light power becomes an issue when you are trying to avoid stretch and keep plants short. Spectrum is also a factor but since you are working with MH and CMH, you won't likely be impressed with half the wattage of T5. I am not knocking T5's I love them especially for veg, (never flowered with them) just don't think they will keep up with your HID's since you seem to have the headroom to use them.

 

[dbfr3sh]

i have a 4 bulb 4foot t5 light set up. i never topped and had a 5 week veg, of course i then bloomed under the same t5s and produced .8 gpw. all stayed small with only one lst.

right now im vegging 3 snowcap romulans and 3 power skunks under my 220w t5s and then flowering on 400w hps. good luck

 

[pinecone]

i have a 4 bulb 4foot t5 light set up. i never topped and had a 5 week veg, of course i then bloomed under the same t5s and produced .8 gpw. all stayed small with only one lst

What kind of plants are those? Are you attributing the short stature to genetics, the cool spectrum of the lights, or both? It doesn't look like they stretched at all.

Pine

 

[dbfr3sh]

they are feminized nirvana snow white (white widow x indica male). there mixed mostly indica probably why they stayed short and im sure the 5000*K t5s helped too. i never topped but always bent the main stem 90* to help aid in the bushing out. just for the fun of it i put up a scrog screen to divide the branches while they stretched in the first 3 weeks of flowering then took it off to finish.

 

[Wacky Tobacky]

400 watt CMH > 4 t5s

no question about it. i have grow with floros CFLs and t5s before. the CMH will have much better light penetration. if those plants in the pics above where grown with the CMH the buds would be fatter, more dense and better trichome production. right now im running a 400 watt CMH and HPS combo veg/flower. my past two grows before were with Floros and then a combo and floros and CFLs.

also the stretch will be crazy with a dominant sativa under floros. CMH will be better. also throw them into flower much earlier and train them.

heres a pic of my sativa under floros. this was almost 600 watts of t5s and CFLs. i dont have any better pics. these pics are pretty old i dont have the photobucket account any more but i found them in one of my old threads here.

oh and let me add that this bud was TRIPPY!!!!!! i found myself sitting at the comp and the screen would be shaking back n forth... lol i gave some to my friend (i didnt tell him i grew it) he told me he was talking to himself.

 

[dbfr3sh]

400 watt CMH > 4 t5s

... if those plants in the pics above where grown with the CMH the buds would be fatter, more dense and better trichome production. right now im running a 400 watt CMH and HPS combo veg/flower. my past two grows before were with Floros and then a combo and floros and CFLs. ...

what? i got over 7oz plus trim for hash off those 5 plants. 300w of t5 and a .8gpw....and definatly not shy on crystal production..

i put 400s to shame

 

[Bionik Kronik]

I hear 10 4' T5s is equal to around a 400 HID (MH or HPS depending on bulbs).

 

[Wacky Tobacky]

dbfr3sh honestly your plants look great and i see you have them dialed in pretty good. but are you seriously going to say that floros are better then HID?
i bet if you had those growing under a 400watt HID you would get better results. im not saying you dont get good results already with the floros im just saying better results.

 

[dbfr3sh]

i do agree and i hope to get that with my next grow. still vegging under the t5s but am flowering with a 400w aircooled super hps

 

[FreezerBoy]

dbfr3sh honestly your plants look great and i see you have them dialed in pretty good. but are you seriously going to say that floros are better then HID?
i bet if you had those growing under a 400watt HID you would get better results. im not saying you dont get good results already with the floros im just saying better results.

You can't say one lamp is better than another without taking the garden itself into consideration. Doesn't look like he has room for a 400 to me. If that's true, a 400 would be a disastrous choice.

 

[dbfr3sh]

not in that closet thats for sure. the 400 is for a 3 x 3 room

 

[pinecone]

If I don't want them to stretch too much when should I start them under the T5s (now, 3 weeks prior to finishing my current crop, or somewhere in between?).

I made this post because I was trying to to figure out when to sow my seeds under the T5 based on the availability of space in my flowering cab. At the time I already had 3 seedlings going under the 4 bulb (6500K) T5, and was considering starting more.

So far I'm really happy with the results I'm seeing, which is to say I don't see an appreciable difference between plants under the T5 and what I would expect them to look like under 400 watts of MH or CMH light (bushy and compact). On the basis of what I've seen so far I'm starting some more seeds.

Pine

A SSH seedling that started the germination process on April 14th and has been under T5 light since sprout