Metal halide and HPS

Is it better to use metal halide in the veg stage and then HPS during flower or HPS is fine?

I’m a first time grower and started seeds with 75 watt halide, week 2… 175 watt metal halide… week 3. 250 watt metal halide… week 4. 400 watt metal halide. Week 5. 600 watt metal halide. When I’m ready to flower was gonna hit it with 600 watt HPS.
I already had all the halide set ups from doing marine aquariums. I’m just curious if I’m doing too much. The grow is going just as planned but wondering if I’m creating too much work when need not.
Doing aquariums in my past has me extremely cautious about lighting and perimeters.


MH in veg, this is because it provides more blue spectrum light which is preferred Durring veg.

You can even watch a YouTube video on the morphology of plants and light spectrums to see the difference but that’s the short answer.

If you don’t mind I have an aquarium question.
Would a single CPO be okay in a 4 gallon biorb with a betta fish and 5 bloody marry shrimp?

What do you think?
I don’t mind the loss, my girlfriend would be crushed lol but I don’t care I just would rather have 5 shrimp then 1 CPO yet I really really want a CPO

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You would be better off with the shrimp and no other fish. Not sure what CPO means because I did coral reef tanks. A good rule of thumb with tanks is one inch of fish per gallon. Which means your pretty close to maxed on fish. snail and shrimp are not included in this as they are considered a natural clean up crew.
Btw very pretty fresh water micro ya got going there .

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Also if you add plants to the tank you can stretch the fish rule because they love the poop fish produce but you also have to have good lighting. And add a small amount of CO2 but they have diy reactors for like $10 can find plans anywhere on the net. I personally would take the beta to your local fish store and trade it in for the exact fish you want… trust me I have had fish I didn’t love and I would stink eye them shits to death.

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The beta is the fish we want lol
I do have it planted one big one in the back and the front little green stuff is one as well.

A CPO is a mini crayfish
Cambarellus patzcuarensis orange

Thanks for the compliment on the tank =)

Then do what you will a fish won’t kill the tank… just make sure your keeping an eye on your ammonia level. 20% water change weekly should keep you solid.

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Updated … in this hobby you over water in the aquarium hobby you over feed… be aware of the amount of food you feed… only feed every couple days not every day and keep it down to a minimum.

That is old school. MH (blue/white) in veg and HPs (red) for flower, but I have used both in lfower with good results.

MH are heavier in blue photons, blue photons reduce cell expansion allowing you to have shorter plants thst don’t stretch as much.

HPS is higher in red photons which has been generally agreed that red helps flowering, although some studies have challenged this theory.
Red photons are 15% more efficient at photosynthesis but the morphology of the plant changes and you get a longer node space, this is not ideal if you want consistent colas/buds.

Of course light intensity is a more important factor then the spectrum but those are some facts to consider.

But led is best and CMH/CHPS is a better option as well you can just go get a better bulb rather then MH /HPS

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I started my latest under 400 watts mh at 30 inches and t
Let them grow and close the gap until I was ready to flip then changed to 600w hps and they’re doing great. Buds stacking quickly

Well that’s certainly good to hear. I’m at about the same distance and they seem to be going well.

I’m sure leds would be a much better choice I just want to make sure I’m successful before I drop some real cash. Started with what I already had on hand. I also won’t really notice the change in electrical costs because I was using these lights in coral reef tanks

Here is the thing. No matter which way you go; From T5 T7, to CFL, or whatever for propagation to MH, HPS, or LED. You and you alone have to make the decision based on your budget and personal choice.

I have so many different almps and ballasts that I do not even know where a few of them are. LOL

Do what feels comfortable. You evolve after you learn for yourself by amking your own choice. Eitehr way. No matter what you choose, you will be able to grow successfully.

Always willing to help someone build a gorw op plan.

Oeace, lw


My next grow I’m thinking I want to change to LEDs based on the heat situation I just noticed over the weekend. I’m gone for 3 days at my summer cottage and upon return noticed the area was hot ass hell as it was in the 90s outside I got lucky by having so many fans or could have been a real issue. I have fixed it by adding an AC unit but certainly not something I want to run all the time.
Do you have an LED set up you would recommend.
I have a 4’x4x6’ tent
Money is not a major issue although I’m wanting to stay below 1k. My spouse is pretty tired of my expensive hobbies. If I could be around $500 I might still get a few kisses here and there…lol

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That settles it. Im going to switch after this grow to some hlg 600’s in the big room now that I know she gonna kiss me here and there. Just for clarification where exactly is here and there? :laughing: :rofl: :joy:

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I might be lucks with a lip kiss…lol she been mad as hell for 4yrs over the 25k I dumped into coral reef tanks. Unfortunately now I’m no longer interested and came up with a new hobby. :joy::rofl::joy::rofl::joy:
After 22 yrs of my shit … Uhmmm yeah she’s not the boss of me.


It may be old school but HPS is tried and proven to grow tight buds. I use HPS and Cree Cobb led at the same time.

Here’s a tip bro, run the MH HPS at night when it’s cooler. Good luck!

I currently run my metal halide off 11am -5pm unfortunately I live in an old Victorian brick home so there isn’t central heat and air. I do like the growth and plan to run HPS during flower just not there yet. I’ve just lifted the light quite a bit to see how that goes, maybe that will work.i don’t have AC running now . I’ve never been a fan of LEDs in the aquarium trade due to coral growth issues but it seems like everyone here prefers it over the MH or HPS. I was thinking it was different with plants but I’m 2nd guessing now that you said bud structure could be an issue.

Depends on the led. Some of these new ones defiantly grow tight bud but cost plenty.

Where as a 600 watt hps is about 120 bucks. Hps also shines in winter when heat is needed. I use both led and HPS

Are you having heat issues? You got a vent fan running?