beebs Posted March 29, 2023 Share Posted March 29, 2023 (edited) If using a CDM alongside an led for temps in winter months, which CDM bulb is best, 4k or 3k? Edited March 29, 2023 by beebs Link to comment Share on other sites More sharing options...
purepotstill Posted March 29, 2023 Share Posted March 29, 2023 4200k is veg only, at least on the paper. I use a 3100k from start to end and had good results (with autos). Link to comment Share on other sites More sharing options...
beebs Posted March 29, 2023 Share Posted March 29, 2023 I've seen reports of folks using the 4k from start to finish 1 Link to comment Share on other sites More sharing options...
KC Posted March 29, 2023 Share Posted March 29, 2023 You can use a blue spectrum for flowering, it will probably yield a bit less though. I've not done it with cmh but I have with normal metal halides (E40) 1 Link to comment Share on other sites More sharing options...
beebs Posted March 29, 2023 Share Posted March 29, 2023 I'm using 2 CMH in my space for my present grow and using 4k bulbs for first couple of weeks flowering in the hope of preventing some stretch, as height is an issue, then switch one out for 3k bulb. 1 Link to comment Share on other sites More sharing options...
Michael Luchóg Posted March 29, 2023 Share Posted March 29, 2023 Some folks say there's different terpene development using the blue light in flower. That's what I did, but I just didn't have another bulb. I'm looking to see if I can find a 150 watt unit. They're like hens teeth I guess, everything on electrical stores/sites is LED. They have lots of CDM bulbs but no unit or ballast. 1 Link to comment Share on other sites More sharing options...
Michael Luchóg Posted March 30, 2023 Share Posted March 30, 2023 I see an ''RX7'' type MH unit. They seem to be discontinued in some stores, an outdoor floodlight I mean. Would you folks think this might be useful for extra light and heat during the winter months, or the wrong type of unit to buy? 2 Link to comment Share on other sites More sharing options...
KC Posted March 31, 2023 Share Posted March 31, 2023 For the same sort of money you could get a electronic ballast with a bulb and a reflector from a grow shop (250w). Not cmh but a normal E40 fitting one. The rx7 would be fine though, I just think the spread might not be very good in that housing. Bulbs are cheap mind. 1 Link to comment Share on other sites More sharing options...
Michael Luchóg Posted April 2, 2023 Share Posted April 2, 2023 On 31/3/2023 at 2:28 AM, KC said: For the same sort of money you could get a electronic ballast with a bulb and a reflector from a grow shop (250w). Not cmh but a normal E40 fitting one. The rx7 would be fine though, I just think the spread might not be very good in that housing. Bulbs are cheap mind. Thanks @ KC I thought of that, well I have one in a flower space but only use it for a few hours every few nights, and a 315CMH balllast, but no bulb and no desire to burn more wattage than I need. Also I'm looking at a wardrobe at the moment, 115cm x 50cm x 180cm(LXWXH) and I have an LED panel, 165 watts . It's a bit of a nuisance because it's too strong. I think some plants ,seedlings don't like the blue diodes so much, but it's OK when turned down. I'm thinking of a wardrobe for vegging and growing autos. The 150w CMH might just be right alongside an LED, and for extra heat. Anyway, asides from maybe a poor spread in the housing, there might be a hot spot. I suppose a fella could leave the glass or perspex on the unit. To be honest, it would surprise me but I wouldn't be terribly surprised if I knew or discovered that a 150w CMH was very near par with a 250w HPS. 2 Link to comment Share on other sites More sharing options...
Goohfy Posted May 29, 2023 Share Posted May 29, 2023 On 30/03/2023 at 7:03 PM, Michael Luchóg said: I see an ''RX7'' type MH unit. They seem to be discontinued in some stores, an outdoor floodlight I mean. Would you folks think this might be useful for extra light and heat during the winter months, or the wrong type of unit to buy? I would only get this if I was worried people are snooping around my grow.There’s a lot better lights heating out there but don’t get me wrong it made me smile.peace Goohfy. 1 Link to comment Share on other sites More sharing options...
Michael Luchóg Posted May 29, 2023 Share Posted May 29, 2023 (edited) Just now, Goohfy said: I would only get this if I was worried people are snooping around my grow.There’s a lot better lights heating out there but don’t get me wrong it made me smile.peace Goohfy. I got a 150w HPS instead! Stupidly though, I did buy a 150w CMH unit but there was no ballast in it. Another item for the recycling centre. Edited May 29, 2023 by Michael Luchóg Link to comment Share on other sites More sharing options...
Goohfy Posted May 29, 2023 Share Posted May 29, 2023 Just now, Michael Luchóg said: I got a 150w HPS instead! Stupidly though, I did buy a 150w CMH unit but there was no ballast in it. Another item for the recycling centre. Are shit yeah another one bites the dust I’ve done it and I will do again.peace Goohfy. Link to comment Share on other sites More sharing options...
Amnesialocal Posted December 26, 2023 Share Posted December 26, 2023 Philips produce a CDM-T 250w bulb 3000K and I assume associate ballast. Anyone try it? Link to comment Share on other sites More sharing options...
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