Metal Halide vs. HPS

[Apu]

I dont really know if this is the right forum to post this in but i couldnt find anything about lighting and im goin hydro so ya. Which is better MH or HPS from what i have heard HPS is a must for the flowering room. I have been looking at MH kits and such to try and save money or just going for a the cheapest i can find. And is a digital ballast better and why. Thanks for any help

 

[cannariffic]

Heres the best thing I've found so far. Get an Digital (electronic) HPS ballast and you can have the choice of running HPS or MH. All you need is to buy a HPS to Metal Halide bulb, which is like 60 bucks. Whereas, if you get a MH ballast and try to buy a MH to HPS bulb, you are looking at spending 100+ dollars.

With HPS ballast, you have the choice to run either or on one ballast.

Second, you can buy those dual arc MH/HPS bulbs. One bulb, with two gas envelopes, one HPS, one MH, in one bulb. Its an awesome looking bulb and I am sure it works just as well. Works only on an HPS ballast.

I actually plan on getting a dual arc in the future.

Def go with a HPS ballast and you have a lot of choices to go from there.

 

[cashmunny]

A lot of growers just use HPS all the way through. They are very efficient. Probably using HPS with a digital ballast will give the most light per dollar spent on electricity.

Ceramic metal halide bulbs (CMH) give off a nice balanced spectrum. But they only go up to 400W and you cannot use a digital ballast. A cheap magnetic HPS ballast should be used with the CMH bulbs.

I personally have a 400W CMH bulb in a closet grow. I'm happy with it.

 

[REZDOG]

If you only have one light,go with HPS.
A "digital" HPS ballast is fine,but it may interfere with your household electronics and land line phones,depending. I've used both,and the digital ballasts are clearly superior-though they seem to not last the years and years that analog ones do.
Digital ballasts start & shut down "cleaner" and provide more consistent power to the bulb,so they're more efficient. The savings in power between the two ballasts is negligible,it's all about the efficiency powering the bulb.



Cheers!

 

[MrBomDiggitty]

how much space are you covering with that cmh? 3x3, 4x4, or more?

 

[cashmunny]

how much space are you covering with that cmh? 3x3, 4x4, or more?

It's about 10 sq ft. 2' x 5' . I think the output of the light is about 30,000 lumens so 3000 lumens per sq ft. Probably a little low but I'm going to cull the plants I suspect to be males and not use all that space. Right now the plants on the fringes of the light are stretching quite a bit whereas the one directly underneath is quite compact.

The bulb produces a lot of heat. Even with the closet door open and a fan going the temp in the closet is consistently about 85 degrees, 15 over ambient. I've been thinking about cutting a hole in the ceiling and venting the hood into the attic. I can't imagine what a 1000W HPS would do in that space. It would be unbearable.

It's getting to be a friggin' jungle in that closet.

 

[REZDOG]

Imo: Use an air-cooled,vented 400w HPS on a 3' light rail.

 

[cashmunny]

Imo: Use an air-cooled,vented 400w HPS on a 3' light rail.

what's this I hear about the digital ballasts actually generating more lumens from the same bulb versus a magnetic ballast?

I've heard that there are a FEW digital ballasts that can drive a CMH bulb , but I was never able to confirm specific make and model.

 

[Hydro-Soil]

what's this I hear about the digital ballasts actually generating more lumens from the same bulb versus a magnetic ballast?

I've heard that there are a FEW digital ballasts that can drive a CMH bulb , but I was never able to confirm specific make and model.

The light you buy isn't going to make a difference until after you've learned to grow and run a few crops. Sounds like your current setup could use a bit more work before you throw any plants in there.

Do a search on here for:

Ventilation 101
Lucas Formula
Basic Water Chemistry
Odor Control (unless you live in the middle of nowhere without guests, or it's completely legal in your country)

That should get you a good enough start that you'll be able to figure out your own searches to your new questions. Once you have detailed questions to ask, you'll get much better help around here and your ladies will appreciate you more.

 

[Apu]

Thanks a lot for all the help fellow ic'ers. I think I'm going to get two 400w hps in abt a 9'x5' room with 8 bio buckets
Grow diary comin soon!

 

[CovertCrops]

MH vs. HPS for trichrome production?

MH vs. HPS for trichrome production?

Hi All,

I have 2 rooms, one room has 2 600w HPS lamps and the other room has 1 400w MH and 1 400w HPS lamp. I am growing the same strain (dirty harry from clones) in both rooms. The 1200w room is 2 weeks ahead of the 800w room yet the dirty harry specifically under the MH is far frostier than any other of the dirty harry. The only other thing that is different is that the 800w room is on canna and the 1200w room is on pbp. I intend to test this further on the next run but for the sake of conversation has anyone else noticed an appreciable difference in trichrome production when using MH?

 

[simedru24]

Hm.. 400 watts for a 9' x 5' room? Youre gonna need much more light to maximize yield. I would say you need at least a 1000w. I have a 4x4 grow tent using 600w Hortilux bulb. That way you dont have to switch lights during flower.

I forget how many lumens per square feet is ideal, but you should check that out!

 

[Lazyman]

Second, you can buy those dual arc MH/HPS bulbs. One bulb, with two gas envelopes, one HPS, one MH, in one bulb. Its an awesome looking bulb and I am sure it works just as well. Works only on an HPS ballast.

I actually plan on getting a dual arc in the future.

Don't bother, HUGE waste of money, and they put out LESS light than a regular 1000W MH, let alone a 1000W HPS! They also cost over $200 a bulb, and since you should replace them twice a year, you're throwing money away.

Don't use Hortilux Eye bulbs (MH or HPS) in any digital ballast, they will burn out FAST. Use Ushios, made in Germany.

 

[Lazyman]

You want a minimum of 50 watts per square foot of flowering space, about a third of that for veg. Works out to about 5-7K lumens per square foot in flower. For a 45 square foot area you would need 2250 watts minimum, 3000 would be better.

 

[REZDOG]

50w/ft2 is The Ideal.
Even on a smaller level....a 1'x3' SCROG with a 150w HPS,for example,is efficient as hell-and you can easily attain The Magic Number,1g/watt[/i],as long as you choose your strain wisely,and know your shit.