Just switched my hps for mh for the last week of flowering

[Crom1904]

I usually just add a 1000watt mh along with the 1000watt hps for the flowering stage always have greater yeilds that way:harvest:

 

[bobman]

what size is the space? 4x8

 

[sedate]

I couldn't take the yellow glare anymore.

Jezus fuck I hear that.

 

[bobman]

update:

Experiment ended yesterday after 5 cycles and I replaced with a hps. I few things seemed to be happening to the plants, that were almost done, witch freaked me out so I went with my instincts and I switched back.

First, a few lower buds seemed to be getting more leafy growth. I had read somewhere that doing this can also trigger the plant to go back to veg growth. Not sure if that was happening but that along with the next couple of things put the alarm out.

Secondly, the plants smell had gone faint. Before the plants had a cat piss pheno smell when I switched the smell become sweet and slightly fruity skunky. Yesterday at lights on they had very little smell and it was hard to interpret.

Thirdly, the main colas hairs were all white. For this plant to be over the number of days I took there mother I would except the hairs or at least some to be turning orange. The weird thing is once I switched back to hps hair color changed within hours. Most of these plants went from not looking done to looking completely finished and I expect after tonight they will all look the same.

Conclusions:
I will try this again and I believe there are potentially big benefits from mixed spectrum flowering. I believe my ushio 7000k was way too much blue.

Trich production increase-maybe to hard to measure.
Yield-I really believe that these plants did bulk up and it was caused by this light.

The plants really seemed to love this light especially the sativas that still have a few more weeks. Those plants really seemed to get going under this light, smell and growth both very much increased under this light.

 

[Jalisco Kid]

jk don't leave us hanging any details.

Like what? JK

I do not believe you saw, smelt, felt, that many changes in 5 days. Next time you change something take pics first to compare. JK

 

[bobman]

How the best rooms are set up regarding mh? And how you have used uv lights?

Smell 100% changed no doubt in both phenos. The smell is returning to the one pheno today. The hairs changed color very quickly once switched back no doubt. Weight gain and trichs are hard to measure even from a photo. I believe some veg growth made them bulk up. The majority of the size increase seemed noticeable on the mid to lower branches. This is also where the veg growth seemed to occur. I will take a picture tonight but my camera is a pain in the ass. It takes a couple of good shots then crap. I understand your skepticism I have a hard time thinking this would happen so quickly but I have spent a lot of time up close studying these plants over those 5 days.

 

[bobman]

Also regarding speed of change this is how I am looking at it. I take this strain to 70 days, 10 weeks. This strain does not do much of anything for the first 21 days or so. If you subtract that from 70 days that leaves around 50 days or less of bud production. I did this experiment for 5 days or 10 percent maybe more of its major bud production. I think major changes could in fact happen in that time frame at least the ones I noticed.

 

[bobman]

also jk what k values for mh in the rooms you were talking about or what would you suggest? I really believe the 7000k was to high.

 

[Jalisco Kid]

I used to use t100 bulbs that peaked at 310nm and some 39w at 285nm after reading some of Raphael Mechoulam's papers. I run them higher then most but for about 6 hours. I run about a 60/40 mix of eye's mh and sunmaster's warm mh. I also use eye's 1000w hps. During flowering I will use an eye hps 1000w with a eye 1000w mh and and a few warm mh's. I might switch up that group if it is around sats ,and go with all reg eye mh's.
Lately I have been running a few strains more then normal and I do not see that big of a change when I switch over the last 2.5 weeks. I also mainly just run 70 day strains. JK

 

[Seamaiden]

i'd like to try this but don't want to dish out 700 on 8 horticultural mh bulbs. think it's worth buying 25 dollar commercial mh bulbs?

Go for it! I'm working with two bare bulbs hung vertically from Lowe's right now, both 400W overdriven to 600W, one on a Quantum ballast (I love that thing more and more every day) and one on an Xtrasun mag-coil ballast. Both bulbs are Sylvanias, both under $25, one HPS and one MH that I believe comes up at about 4200K color temp.

The plants under the MH are shorter and more compact, so they're going to be rotated. However, I am completely blown away at the overall structure, growth rate and general 'happiness' of the plants in this set-up. It's working very well so far.

 

[seventhchild]

, both 400W overdriven to 600W,

HOW DO YOU DO THIS AND HOW MUCH DOES IT SHORTEN BULB LIFE? [sorry about the cap lock]

 

[Seamaiden]

I screwed the bulbs into their sockets, left the room and started the timer. I left the room because I was afraid, seen too many MH bulbs pop. I have no idea how much it may shorten bulb life, that was part of the reason why I did it, I wanted to see what would happen.

Sorry I don't have more information for you.

 

[Tobor the 8th Man]

Why would you do that seamaiden? I would think an overdriven 400w will not have the output of a 600w and your ballast would still be sucking up 600w of power. This seems wasteful. Buy a 600w bulb.

 

[Seamaiden]

My reasons have a lot to do with sourcing, as I am limited. I decided to give it a try, not knowing a hell of a lot about it other than it will likely dramatically shorten bulb life. I figured, Why not give a try? <shrug>

When I make another special trip to the hydro, I'll pick up some appropriate bulbs. But for now it's either underdriven 750W-1,000W (not even sure I can find that at Lowe's/locally, those 400s were the highest wattage I could find), a single old 600W HPS, or those bulbs.

 

[namaste]

mmmnn intresting :)

 

[mc1969]

I usually just add a 1000watt mh along with the 1000watt hps for the flowering stage always have greater yeilds that way:harvest:

kinnda the same here 1000 watt mh 3 400 watt hps works great

 

[lilredwagon]

i'd like to try this but don't want to dish out 700 on 8 horticultural mh bulbs. think it's worth buying 25 dollar commercial mh bulbs?

If you are using digital ballasts, check with the mfr. there could be a problem with the commercial bulb strike voltage- I have heard... always best to not blow up your stuff! :angry

 

[doctordank]

i guess thr rev from skunk magazine also preaches this style of lighting. im thinking about trying it out on my next grow!

 

[Nobodynobody]

know a fellow that flips to MH last few weeks. It helps to make dence buds. Wish i can do it. however got no room to open my hood by that week.... no room.

 

[motherlode]

one thing i always was curious about is that growers always say that hps mimics the fall sun colors. i would think the sun rays are always the same. do par values or spectrum from the sun really change in the fall. Is there any science behind that or is that human perception? I always notice blue crisp light in the fall where i live. Maybe the suns relationship to our atmosphere filtering changes par or spectrum?

in the fall the earth tilts on its axis increasing the distance sunlight has to travel through the atmosphere reflecting more red spectrum