How and when to switch from 600w MH to 600w HPS

[Surf420This]

Ok guys, hit day 28 Veg yesterday (4 weeks for those too stoned to count ))...Not too far from making the flip and want a head start before it gets here. I am using a 600w MH for Veg and will switch to 600w HPS for flower. My question is, do I switch the bulb a week before 12/12, right at 12/12, or right after 12/12? Also, when I flip should I use 1/2 strength grow nutes with 1/2 strength bloom nutes, or just switch cold turkey? Please let me know if my girls seem like they are on the right track.

 

[Julz]

21 days.. is 3 weeks, I would give them 1 to 3 more weeks of veg for your tent. I would change the lamp from MH to HPS when you change the timer to 12/12. 18 hours of HPS is a lot. Its much different light from the MH. Depending on your nute line, you can just add your bloom to your current mix with the veg nutes in there. Just check and see if your veg nute is high in nitrogen. Too much nitrogen in bloom causes stretching. If it is, ditch it after the third week in flower and just make a bloom mix.

 

[Surf420This]

Lol thanks I meant 28days,updated. As for the lights,thanks,sounds good to me. I'll give that a go. The nutrients line I'm using is roots organic grow and bloom.

 

[Julz]

Roots is a good brand, I would stick with it if its working for you in your environment. I'm going to assume you have Roots Buddha Grow? Which has no nitrogen, and could probably ride along in your bloom nute mix just fine maybe stop it week 3-5 to reduce your PPM so you can add some bloom boosters towards the middle-end. If you are staying organic, unsulphured molasses is a good additive. Roots organics uses it in their line or you can buy it stand alone and add it. Blackstrap and Grandma's seem to be the favorite brands. Hope this helps you along the way.

 

[Surf420This]

Damn, good info Julz. I appreciate it. Yeah im trying to stick with the same nutrient line throughout. Not trying to add any more stress to the girls than needed. Im gonna give your advice a go come time to flip. Good lookin out! Ill keep ya updated

 

[Julz]

Happy to help, in the beginning its a ton of info to try and cram into your head! Its best to learn from doing so don't worry if you feel like you make any mistakes just keep truckin' forward.

If you have a chance, I would grab a small bottle of superthrive, and give it only to the very short plants to try and get them to grow a bit taller so they match up a bit more to the taller plant. Once you start flower you will want them to all kind of reach the same point at the top. If you still have shorties just put something under them, so the top of your canopy is level to your light.

Can't wait for your update