400w MH or 600w HPS for stretch?

[Zen Medz]

I have a Lumatek digital ballast that allows 400 or 600 watt settings. After veg I have been keeping the 400w MH in until 10-14 days into flowering then I put my 600w Ushio HPS in. It seems to control the stretch a bit but I'm curious if it's hurting my overall yields with the lower output. Any comparisons or thoughts? 400w MH for first 10-14 days of bloom or 600w Ushio HPS? Cheers.

 

[coolbud]

if your having issues with the stretch and cant let them stretch like the hps would then just keep the mh untill the stretch days end , it wont hurt your yield with nothing.good day

 

[Zen Medz]

Coolbud, I have a 3x6 table on top of a cabinet so I can only let my ladies get 3.5 feet max at the end of their stretch. I'm going to use a screen this go round and usually just run my 400w MH for veg and during stretch. I think I may take a small hit on my yield but I don't think it's that much. For a typical 9 week strain running a 400 MH for 10 days out of 63 days is only 15% of the total bloom cycle. If there was a minor difference between the two bulbs it's probably not noticeable because of the short period that it's being used. If anyone has done any comparisons I'd love to hear some feedback.

 

[habeeb]

some people use MH for flowering. saying HPS lacks

I wouldn't be concerned, yield would be more dictated by root space / plant size / genetics then light intensity alone..

another way to control stretch if you need to, is topping