600watt dimmable mh

caper40

Active Member
i just purchased a 600 watt dimmable ballast which accepts both mh and hps bulbs question i have is when my seedlings pop do i put them on the 600 mh or have it turned down till they grow a bit then turn it up
 

6ixclouds

Well-Known Member
I have one too, I've only used the HPS Bulb but the MH is a bit hotter. I'd say start off at 300w mode they don't need all the power yet, and that way you can keep the light closer. Just remember to always make sure that when you rais or lower the light sure that you put your hand in between the plants and the light, about a half inch from the top of plants and hold it there, make sure it's not too hot for you to hold it there comfortably and you should be good. How many plants though, and what size space?
 

caper40

Active Member
germinating 5 seeds hoping to get 4 seedlings and they are white cookies from crop king my tent i around 5x5 with about 6 ft of height
 

6ixclouds

Well-Known Member
Nice! Good luck! You can start the light lower in the tent on 300 and put your cups or pots close together under the light, then raise and turn up as they grow just like you said earlier,, long as you keep it close as you can while making sure it wont burn you'll be good :)
 

herballuvmonkey

Well-Known Member
I would keep them under cfls or fluorescents until you get a decent tap root then put your 600 on them at full power 18-24 inches away. When you dim your light it stresses the bulb and you will get less time out of it. Use the mh until flower switch to hps in the 12/12.
 

tropicalcannabispatient

Well-Known Member
how do u know if u have a decent tap root
By the foliage, abundance of leaves., i wouldn't use that 600wt yet, IMO is just a waste of electricity, since they are seedlings, they dont need that much light., but if u dont have anything else I'll recommend from 2 and half to 3 and a half feet, that 600wt is overkill for seedlings and a waste of light. Of course IMO, u might fry them. Good luck!!!
 

6ixclouds

Well-Known Member
yea if you dim it low and keep it far to start your'e good just pay attention and either turn it up or move it closer if they are stretching... whatever wont fry em lol. just always do the hand test test before leaving it after changing the light's height. tropical is right I'm pretty sure, I've read It'll lower your bulb life to dim but oh well, i do it, ill just have to buy a new bulb sooner. It's handy though.
 
Don't dim your bulb, raise and lower the height of your fixture. You want to keep lots of light on your plant to try and keep it short and squat. Dimming/less light often leads to stretching and more bulb changes. Put it 4ft away from top of small plants. Herballuvmonkey is right when they get stronger you move the light closer slowly. I never move my lights more than 6 inches up or down in a day. You have to let your plants adjust. Make sure your light distance moves with the canopy as it grows. Finally, monitor your water closely as to not drown them and cause mold versus under watering and them dying. You want to get it right in between to get the roots to stretch for more water.
 

209 Cali closet grower

Well-Known Member
Hit them with a t5 or cfls first. Then use the 6, a month later.

If you want to use 6, now dim it. To 300. Check heat with back hand. If its warm, it's to hot for seedlings.
 

caper40

Active Member
had to ship back my 600 w setup it wouldnt startup but on the bright side i got some cfls and my seedlings all popped out of the soil
 

hotrodharley

Well-Known Member
no more 600 in stock went with a 400 instead hope its enough
Should cover a 4'X 4' area well enough. Keep them under CFL a bit but I put them under the MH very quickly but at a distance. 16" is a good start and then raise the plants to it or lower the fixture. I lower an inch a day with new seedlings/young plants.
 

herballuvmonkey

Well-Known Member
Was it magnetic or digital ballaet. A lot of times the magnetic ones wont start because of a bulb. Had that a couple of times when i was using them. I use str8 digital now
 
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