My plants look nice they are flowering should I switch from metal halide to a higher wattage HPS bulb?
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MH to HPS
- Thread starter TylerInNiagara
- Start date
That's what I was thinking.
I've had plants under a 600 watt HID fixture since October and I've alternated between bulbs a few times just to observe what would happen and to tell you the truth, I don't see any difference in the amount of buds and flowers using either light. I have the MH bulb in right now and have tons of flowers on the fatalii, cayanne, butch T, Bhuts and jalapeno (those are the only ones big enough for flowers or fruit right now). Now, just to uproot the other myth, I had the plants under the HPS bulb for a long time when they were younger and none of the plants look leggy. Instead, they are very compact and sturdy.
I like the fact that the stats on the HPS bulb say it puts out almost 40,000 more lumens than the MH bulb, but other than the light being a piercing red that hurts your eyes, I didn't notice the plants doing any different than under the MH bulb.
millworkman
Extreme Member
Higher wattage yea. But switching from mh to hps is pointless. Save your money.
Mainly because you have 600 watts of light, so it's hard to make a leggy plant under those conditions. What I said may also be strain specific. You may have peppers without certain proteins that control for the flowering process.
I've had many plants that I've grown that once I put under more yellow light of equivalent wattage were able to stretch more and produce more flowers (such as the micro Tina tomato I recently grew)
millworkman
Extreme Member
If peppers stretch they produce less buds and flowers. More nodes = more pods for peps. Keep em bushy and they branch out more producing more flowers and fruit. DIFFERENT LIGHTS ARE NOT NEEDED FOR PEPPERS TO FRUIT! MH/HPS, blue/red, it DOES NOT MATTER... Don't know how many times it has to be said.
Sorry Idosimon, but 600 watts really isn't a lot of light for the size and quantity of plants I am jamming under the light. There is at least 8-10 full grown pepper plants, a tomato and a basil plant all competing for the light. I stand behind my observations I posted.
This pretty much sums up my experience over the winter.
The bulb was free from a friend.
A lot of the time you won't really notice much of a difference as in a typical garden there's a bigger restriction/modifier to growth then the light spectrum, as long as the intensity is high enough plants will thrive and it's best to worry about other factors. Like fresh air, which people mostly forget about. As plants don't have lungs, they rely on the breeze to supply fresh air. Without a breeze, a leaf will use all the CO2 around it withing 2 minutes on average, shutting down photosynthesis, a couple simple fans are really a great investment. This may not have anything to do with your garden Tyler, just an illustration of how other variables will effect growth.
Another example for different variables effecting internode length is day/night temperature differences. Assuming you turn your lights off, the difference between day/night temps will effect how leggy/compact it is. Professional greenhouses will control that difference to tailor growth to their needs, the bigger the drop the more they'll stretch, the less difference or if it gets warmer then most plants will become more compact. Once again, that's usually a bigger difference in most gardens then the light spectrum.
Lumens are a measurement of light visible to the human air, which see's yellow better. As plants use blue/red wavelengths most, lumens aren't a great way to measure light output. PAR Watts (photosynthetically active radiation) measures how much light is put out that's useable, when you compare PAR watts mH & HPS is much closer. So unless you need a specific spectrum (or higher uv-b) then it really doesn't make much difference.
I've got 16 peppers crowded under a 400w MH. I do have a switchable ballast with an HPS bulb, but I've seen no reason to swap. I've already got loads of flowers and the plants are happy. I'll move them outside the last week of March and be piling up pods before July. Also, I recently changed from 18/6 to 14/10 and saw a way bigger difference than MH/HPS makes on peppers. Now is the time for structural growth. As long as you have enough wattage, don't sweat the light color so much.
The only reason i have found to switch between the two is temperature, if i am struggling to keep things from melting down... i switch to the HPS which runs at a much cooler temperature. Other than that... Any plant i have ever grown under HID's prefer the bluer MH.
Could you reference this? I've used both mH and HPS for years and never noticed a difference in heat output.
Dont switch just run both! Lol
1000w hps & 400w mh.
1000w hps & 400w mh.
TylerInNiagara said:
When u are growing indoors u use MH for vigorous growth (intense daylight resemblance) and when flowers start to appear u should switch over to HPS (resembles
the early morning and evening sun)
But that would be pretty expensive in electrical costs. So I'd prefer to grow them under CFL or T5 and for blossoming and podding I'd switch over to HPS
millworkman
Extreme Member
Blah blah blah. Its been said before. No need to switch.DevilsEyes said:
millworkman said:
Next season I will do a comparing test like here : http://www.3ch.co.uk/hps-vs-cfl/info_104.html (comparison of 150W HPS vs 250W CFL)
Will keep everybody informed about this, as I"m curious myself about what the difference would be.
Some say that its all the same (like our very polite moderator
), others say MH for growing and HPS for podding/flowering.