Lighting question

[buckeyebonger]

I purchased a new light system which holds 2 bulbs. I got the ballast for 600 watt bulbs and found that there were MH bulbs that used the same ballast as HPS bulbs. I bought 2 of each. I used the MH bulbs for vegetation and the plants look great. I noticed on the box for the MH bulbs that they were "conversion bulbs" which have the light spectrum for both MH and HPS. The plants are now ready to start budding. Which would be best, HPS or the full spectrum MH bulbs which also have the HPS spectrum? I'm sure both would work, but would only HPS spectrum light produce better buds than the full spectrum MH bulbs? Conversly, would just MH be better for vegetation than the full spectrum bulbs?

Both bulbs are by Ultra Sun.

 

[BudAficionado]

Someone who has done side by side grows will be more qualified to answer, but given HPS greater effiency, you should get more lumens/intensity from the HPS bulb if it's the same wattage, especially in the red spectrum. Also, with a lessoned blue spectrum, your buds should be more dense with HPS. This is all imho, you understand. Using one of each bulb might be an interesting option as well.

 

[Hogdady]

The term "conversion" refers to the MH lamps ability to be used in conjunction with an HPS ballast.....

 

[buckeyebonger]

thats the direction that i was leaning. the bulb can only put out so many lumens and i want them to be red spectrum. but at the same time, i thought that the blue spectrum combined with the red might make it bushier and larger and produce good buds at the same. don't know. i think that i will try just hps this grow and then the conversion bulbs next time with the same seeds. it has a chart on the side of the box that shows as much red as the hps bulb. or as suggested try one of each. since the bulb uses the same ballast, as noted , it will be no problem. it will obviously take some time, but i'll post the results. if i get the same yield with the full spectrum conversion bulb, it will be convenient since i only need to buy one bulb rather than alternate between hps and mh. then i'll have to find out if just a mh bulb gets better vegetation than the full spectrum.

 

[Hogdady]

I honestly think that you are splitting hairs here....I've seen tremendous results with just hps start to finish.....just my observation

 

[Giantsfan24]

I'm using a 7200K MH bulb, will go to a 4000K MH for the first couple weeks of flower then over to a 2100K HPS bulb for the remainder until harvest.

The theory is that the intermediate bulb will reduce the stretching of the first two weeks of flower and make the internodal distance shorter.

I've never done this but it makes sense on paper...