Alternating mh & hps semiweekly during flowering

eachnewhour

eachnewhour

Well-Known Member
Would it be a waste of time and effort to alternate between 400 mh and 400 hps every other week (or so)? I can't afford another reflector and ballast and I certainly could not manage the heat of 2x400w, but I've been reading about mh during flowering may increase potency (and decrease yield).

thank you
 
Welcome to the site, eachnewhour!

I am no expert, so i have never tried it and have never heard of doing this. Common practice is to use MH during veg and HPS during flowering.
 
start off with mh for vegg, and as your plants get bigger and you goto 12/12, use hps or even better both, ive herd you can use mh whilst flowering with hps.
but if your only wanting to use only one lite. id go with the hps all the way.id say dont be swaping all the time, it may mess with the plants cycle.
 
keep us posted if you end up experimenting with that. althought it is typical as email said, to veg with mh and flower with HPS.

theres no harm in trying and we can all learn from someone elses trials!
 
I know that common practice is mh for veg and hps for flowering, I was merely thinking of experimenting a little after I read about how mh during flowering may increase the amount of crystals, especially on sativas. Some people are reporting a substantial difference (a much more "up" high).

Next grow (C99) I will give them some mh during flowering, but mostly hps. Maybe a 2:1 ratio, or so. 5 days with hps, 2 days with mh. And I will keep you posted, but if anyone have anything to say about this, I'm all eyes.

thanks!
 
go for it man.

i think ill give it a shot too on a small crop. im about to start flowering now, but its a crop of Ice and i really want to see my turn out with my regular practices. i have some seedlings in soil that are still young, so a couple weeks ill get on this.

keep us posted and ill do the same once the next crop gets rolling.
 
eachnewhour said:
I know that common practice is mh for veg and hps for flowering, I was merely thinking of experimenting a little after I read about how mh during flowering may increase the amount of crystals, especially on sativas. Some people are reporting a substantial difference (a much more "up" high).

Next grow (C99) I will give them some mh during flowering, but mostly hps. Maybe a 2:1 ratio, or so. 5 days with hps, 2 days with mh. And I will keep you posted, but if anyone have anything to say about this, I'm all eyes.

thanks!
Click to expand...

That's cool - experimentation is important. You could also try using both kinds of lights for the duration of the grow (that's what i do - i use a dual-spectrum).
 
i just saw on another thread, that a first time indoor guy found a 2in1 swtichable ballast (works with both hps and mh), which would make this experiment really easy. i asked him to post the link, once i get it ill put in on here.
 
there are a lot of switchable ballasts but the one i'm talking about has both an MH and HPS ballast. It is designed to use both lights (a 600w HPS and a 400w MH) at the same time or individually.

here is a link to the product (mine is the 1000w Sun System 7 - but there are others):
MH/HPS Dual Spectrum Grow Lights
 
email468: Yeah, mh and hps simultaneously would be awesome. I envy you :) Unfortunately I can't afford this yet (ballast, reflector, ventilation, electricity, you know). But maybe one day, maybe one day...

storzbickel: Yupp, got the mh/hps ballast already plus the bulbs. Got it from Headshop , Growshop , Bongs , Shisha , Waterpipes and Smoking Accessiors, for the record. And I'm glad to see you are willing to try this aswell! Just don't blame me when we both fail miserably ;)
 
not at all. i had alot more females in my leading crop now than i expected. so it wont be too much trouble if any of the blueberry group fails. i dont think we will have horrible turnout.

and email. so from my understanding both lights are pumping at the same time, which is where the "full spectrum" comes from?
because that blows the product i linked out of the water.

and can you run each bulb independently? i guess that could be a stupid question , because why would you want to if you can run both at the same time...
 
eachnewhour said:
email468: Yeah, mh and hps simultaneously would be awesome. I envy you :) Unfortunately I can't afford this yet (ballast, reflector, ventilation, electricity, you know). But maybe one day, maybe one day...

storzbickel: Yupp, got the mh/hps ballast already plus the bulbs. Got it from Headshop , Growshop , Bongs , Shisha , Waterpipes and Smoking Accessiors, for the record. And I'm glad to see you are willing to try this aswell! Just don't blame me when we both fail miserably ;)
Click to expand...

I saved and saved after getting very tired of dealing with crappy lights. i haven't regretted the dual-spectrum light but seeing the results using LEDs from VictorVicious has me second-guessing spending so much. But i'm happy with my results so i guess it really doesn't matter.
 
Here are some pictures - the ballast has a 600w HPS and a 400w MH capability and the reflector can hold both bulbs at the same time. You can run them at the same time (dual-spectrum) or independently. not the same as switchable which you have to run one or the other but not both simultaneously.
 

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i have a very powerful exhaust fan for the cabinet and the lights are air-cooled with a different exhaust fan. Otherwise, I think the temps would get way too hot. It helps that i live in a cool climate.
 
hmm.

i have a small exhaust fan in the room, but one of the walls is an exterior wall, so had went so far as to triple insulate it so i could keep a good temp going.

im about to order one of those right now, but im going to have to see about a larger or additional fan. going to have to take some measurements....
 
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