Leaving an MH light on through flowering...

Curious what effect it might have on the girls. If the MH bulb were never traded out for the HPS, what would happen? I suspect that it would just lower yields some but they would still flower and those flowers would be fine. A bit smaller maybe, but still fine. Thoughts?

Yup some say blue spectrum light loke MH has more potent flowers. I go for a mixed spectrum though.

Ive never re-invented the wheel with anything in my grow. But some people here would defend flowering with mh to the end.

l keep the Mh thru week 2 flower, then put the little sun on them.

MH will give you fluffy potent bud, and much more leafy plants. HPS will give you denser bud, aka more weight. The reason MH gives more potency is the Blue/UVA/UVB (especially UVB) stimulates the plant to produce resin, as resin protects the plant from UVB light. I never use MH, but I added in 2 tanning bulbs to provide UVA/UVB and some blues for flower. Most people use reptile lamps instead of tanning bulbs (tanning bulbs require a special fixture [built my own fixture]) as they fit standard fluorescent fixtures.

So, @nomofatum, if you weren't worried about electricity costs could you run both an MH and a HPS together?

SativaSumo said:

So, @nomofatum, if you weren't worried about electricity costs could you run both an MH and a HPS together?

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Yes, but you would want 2 HPS for every 1 MH (or to run a lower watt MH) and it's difficult if not impossible to get them to mix fully before the light reaches the plants. I want the UVB effect mostly so I went with a bulb designed to produce UVB light that also kicks out UVA and some blues...

Mixing MH and HPS is generally left to large grows with tall ceilings.