600 Watt Blackstar vs 1K HPS - Flowering Problems - No bud sites

So I am a newby to LED but I have grown the same Lemon O.G. strain for 5 years now under 1000 watt HPS with amazing results. I regularly pull 1 - 1.5 lbs from each 1K light with this O.G. I veg for 4 weeks and flower for 8 weeks.
I grow in ebb/flow buckets, I use House & Garden nutes (+ Budswel, Sweet, and SM-90 in flower).

I currently am running two rooms, identical setups with the only exception being the lighting. They each have the same strain, same clones from the same mom, vegged side by side under CF, then split to the two rooms. Same nute schedule.

One room is two 1k HPS air cooled hoods over 16 - 3 gal buckets w/ 55 gallon RES. The second "new" room is two 600 watt Blackstar UV + two 240 watt Blackstar UV (supposedly roughly equivalent to two 1K HPS) over 16 - 3 gal buckets w/ 55 gallon RES.

I am experiencing the strangest problem I have ever encountered in all my years of growing. My two rooms are on the same flowering schedule. My HPS room is currently in its 8th week (flush) with massive, swelled up, stinky ass buds. My LED room has never started flowering. The plants in the LED room just kept growing like they were in VEG. They look good, they just wont kick into flowering! The first three weeks I just chalked it up to LED's taking longer to start. By week 5 I decided to just stay on the week 5 nute schedule since giving a Shooting Powder boost of P seemed foolish. Now I am starting to wonder what the hell it could be. I have absolutely NO light leaks - I have triple checked. My local Hydro guys are also stumped.

The only other run I did with LED was this same room set up but with only the two 240watt UV Blackstars and one 250 watt HPS. I got a decent flowering cycle altho my 8 week Lemon O.G. took 10 weeks to fully finish, the yield was so-so, but I was happy enough that I decided to invest the $1400 for the two 600 LEDs. I added the two 600's this run and removed the 250 watt HPS. I expected some differences but...

I simply don't have the power in my rooms to run a second set of 1K HPS and cooling fans. I thought that LED was my solution.

Has anyone else ever experienced this? Any solutions? Thanks!!

No I haven't but have you verified that there is not an error in your timers and the light schedule getting screwed some how?

#1 Check the timer first...........#2 Are you using a digital timer with those blackstars???? if so when the timer hits lights off go into the room and look at the panel, their may be leds still running dimly .......digi timers still let a trickle charge through which could keep the blackstar leds lit/ these particular panels have a known ground fault due to a shitty design........replace with a mechanical timer and fix the fault(check rasser's thread)...........No MJ strain should be still vegging without a light issue....good luck

PSUAGRO. said:

#1 Check the timer first...........#2 Are you using a digital timer with those blackstars???? if so when the timer hits lights off go into the room and look at the panel, their may be leds still running dimly .......digi timers still let a trickle charge through which could keep the blackstar leds lit/ these particular panels have a known ground fault due to a shitty design........replace with a mechanical timer and fix the fault(check rasser's thread)...........No MJ strain should be still vegging without a light issue....good luck

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This is insightful stuff, good to know!!

PSUAGRO. said:

#2 Are you using a digital timer with those blackstars???? if so when the timer hits lights off go into the room and look at the panel, their may be leds still running dimly .......digi timers still let a trickle charge through which could keep the blackstar leds lit/ these particular panels have a known ground fault due to a shitty design........replace with a mechanical timer and fix the fault(check rasser's thread)...........No MJ strain should be still vegging without a light issue....good luck

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^^^Listen to psuagro. Some of those blackstar units remain on dimly after they go out, all night, until they go back on again. It is a faint glow but will fuck your grow up good. Just wait until your timer goes off and once it does stick your head in there and see if the panel is actually out. I did not have this problem with my blackstars but others have so it is definitely one of the first things you should check.

Yup it's your problem right there. You must run the blackstar through a power bar (or surge protector or something) or else it stays lit all the time (my 240 does that...).

Sorry to hear you bought 2 of them though. Why did you wait for the other room to be all done before asking!!! you spent 2 months thinking they were just about to bud? Also, I am sure you know but the 2 bs 240 are about 270watts together and the 2 600 are drawing about 600W together. 900 actual watts for LEDs should be replacing your 1k light easily, not 2 though!! Look at other brand if you chose to get more leds ... you know what I think of Blackstar! let us know how it goes.

Hey All - Thanks for the replies but like I said in my post I have TRIPLE checked lights and there is total darkness, not a snatch of light from leaks or from units not shutting off. I am not a newbie when it comes to growing indoors, just a newbie to LED.


Thanks for the info on a digital timer still feeding some power to the lights, I had never heard of that but it makes sense - it just is not MY problem.


Oh and hey thanks for chastising me Endur0xX - it really helps alot when you try to make someone feel stupid! I love that you begin your comments with - "Yep thats the problem" - its not. Hearing from "experienced" growers like you is exactly why I avoided posting here for so long… I checked out your grow journals - IMHO if you are growing that many strains at once you still have some learning to do. But what do I know huh - I bought Deathstars?


I have not just waited two months to try to fix this. I actually have been asking actual fellow growers in person about this problem for weeks now as well as trolling grow sites like this one before in a last ditch effort posting here. Like I said my strain is a 8 week O.G. - its always week three that I start getting true bud sites, it was about week three that I started to notice problems.


I turned off my Big Blue Ozone generator as I have begun to suspect that somehow it might be responsible - I have had some leaf yellowing that I had attributed to the LED's being to close to tops that may not be that. I have not smelled it as being excess but at this point I am trying to eliminate all the variables. Think I will give it another week to see if anything changes.

Calm down^^^we are trying to help you.......so by this point your nine weeks in with no signs of flowering?? and you think its NOT a light issue??so you've triple checked everything that may have a light source(timers/meters/powerstrips/etc.)...your ozone generator is it UV bulb or corona discharge method? both create a light source....you may be correct on your culprit...........good luck

Ozone generators release very dangerous levels of ozone gas and are very bad to have in the grow room and around people and animals. Ozone gas is toxic to plants. That is probably your problem. Ozone if not regulated in very small doses can cause respiratory problems in people and animals. The filters and bulbs have to be changed regularly to prevent poisonous gases. They need to be calibrated in the parts per million but none of them are.....

Hepa filters are much better and safer. for smell just get a scrub filter. that works the best

Fantasy Farmer said:

Hey All - Thanks for the replies but like I said in my post I have TRIPLE checked lights and there is total darkness, not a snatch of light from leaks or from units not shutting off.

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No, What you said was "I have absolutely NO light leaks - I have triple checked." - You said jack squat about whether you checked your equipment for lights staying on etc etc. Which is why we brought it up.

Fantasy Farmer said:

Thanks for the info on a digital timer still feeding some power to the lights, I had never heard of that but it makes sense - it just is not MY problem

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^^^And there you have it. You never heard about it so you never checked for it therefore your previous statement about triple checking is pointless.

Anything else you want to ask about? We'd love to supply you with more help so you can come back and act like a dick to us.

Fantasy Farmer said:

Hey All - Thanks for the replies but like I said in my post I have TRIPLE checked lights and there is total darkness, not a snatch of light from leaks or from units not shutting off. I am not a newbie when it comes to growing indoors, just a newbie to LED.


Thanks for the info on a digital timer still feeding some power to the lights, I had never heard of that but it makes sense - it just is not MY problem.


Oh and hey thanks for chastising me Endur0xX - it really helps alot when you try to make someone feel stupid! I love that you begin your comments with - "Yep thats the problem" - its not. Hearing from "experienced" growers like you is exactly why I avoided posting here for so long… I checked out your grow journals - IMHO if you are growing that many strains at once you still have some learning to do. But what do I know huh - I bought Deathstars?


I have not just waited two months to try to fix this. I actually have been asking actual fellow growers in person about this problem for weeks now as well as trolling grow sites like this one before in a last ditch effort posting here. Like I said my strain is a 8 week O.G. - its always week three that I start getting true bud sites, it was about week three that I started to notice problems.


I turned off my Big Blue Ozone generator as I have begun to suspect that somehow it might be responsible - I have had some leaf yellowing that I had attributed to the LED's being to close to tops that may not be that. I have not smelled it as being excess but at this point I am trying to eliminate all the variables. Think I will give it another week to see if anything changes.

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Sorry I didnt mean to be rude. I was confirming what the other guys said because I had the same problem. I dont pretend to know everything at all I am a beginner.

this guy seems like he's just trying to narc on led's since he discredits every idea of the problem and keeps insisting the ONLY difference is the lighting?

One thing i have seen, is some strains just don't like led lights, other strains love it. Maybe your strain just isn't going to work under leds.

i dont know. im all for new tech and all, but i still dont undrrstand why we continue to re-invent the wheel. God knows i have wanted to try leds for awhile but me and hps go waaaaay back, i just cant seem to do it. if it was my grow i would take that led and sell that bitch and get another hid light. yea they might be more heat and more power but nothing beats it right now for monster buds grown correctly. its kinda like when i test drove an electric motorcycle a few weeks ago. topped out at 100 miles an hour looked like a relatively nice cafe racer, but when i hit the accelerator i didnt get that awesome suzuki gasoline driven katana torque so i said fuck it. im not knocking the early adopters, im sure in the next decade leds will probably surpass the hid lites but if ur not nasa why risk ur grow?

unless u have a shitload of cash and just want to research

Im not in it for the research but with the heat i get where i am a hps is never going to be a solution without insane ventilation so thats where the are a plus, i haven't heard this thing about different strains being worse under LED maybe that's where you should be looking because it doesen't seem like anything else, i'm gonna go research that now in fact! if led's just aren't as good we'll have to do everything else right then!

It was likely the ozone, I am getting bud sites now. Replanning the ventilation set up for next turn.

Thanks for the help those very few of you who bothered to do more than just skim my very detailed account of my problem and didn't waste your own time bothering to type your vitrial. Yea I am the Narc Dick here... thanks for schooling me. I am sure you will be happy to hear you wont ever have to hear from me again.

Hopefully someone else who has this problem will come across this thread and be helped.

keep us posted on what u end up getting

I wouldn't blame the LED's out right but they do have some issues with leakage or trickle currents. that being said, you grew fine with blackstar 240s before... and im pretty sure its physically impossible for a MJ strain not to flower unless it is stressed or something.... What i think... is your a big boy with lots of toys... and you need to go back to the basics.

If you put your plants in a ventilated room with just one of your lights and nothing more im gonna assumme they will flower... unless you found some specific strain on grass that doesnt respond to your particular spectrum from your Blackstars.....

go back to the basics and build up to where you are... when you see things stop working then you got your culprit.... but if your plants grow ( like in veg ) with the lights... then the lights are working just fucking fine. if your plants died i would be worried... sounds like your fucking up.

Ive never seen anyone else growing with LED's simply have their plant not flower... dont jump to conclusions... base your hate for LED off facts.


also i assume you're a comercial grower...

also ozone with literally oxidze your lungs.... so i would focus on the harmfull UV light to get more trics.... no harmful air for you or any other poor soul who lives close by (being comercial people dont think of others in the housing complexes or neighbourhoods)