Philips 315w CDM Elite (CMH)

[Dank Whisperer]

...better than 600mh any day...

There's a common misconception regarding those, don't know if you know. 600w is HPS only, and MHs are conversion bulbs made for HPS systems -- like the CMHs made to retrofit into 400w MH systems. Not the same difference in performance you'd see between HPS and MH in the 250, 400, and 1000w segments. I don't think conversion-type bulbs, or dual-arc bulbs for that matter, are ever as capable as what they are made to replace. I assume they include a component that creates a loss.

 

[Dank Whisperer]

Wondering if these CMH would be a good upgrade from the t5's and maybe produce vegged plants that would handle the Gavitas a bit better and maybe require little or no dimmed period. Thoughts?

I swear I remember somebody saying they needed to be hardened-off before going under the CMH, which he achieved by keeping the light(s) up high at first, but they could also dimmed with a Philips ballast. I don't have first-hand experience, but I'm sure others who do will tell you that "upgrade" is a bit of an understatement. Intensity will not be an issue from what I understand.

I'm outgrowing my fluoro fixture for vegging, so I'm in a similar position as you. I was going to convert to a 400w system for veg, until I came across CMH. It's in the realm of 600w HPS in terms of weight, and quality seems to be improved by most accounts. You can run them all the way through flower, but I've got a new DE that will be in service for a while (not that I won't be flowering with the CMH as well). Now I know why all of those 400w systems are on CL[FONT=Arial, Helvetica, sans-serif]

[/FONT].

 

[Scrappy-doo]

That's the answer right there thanks for the suggestion Rives. Didn't even know the philips ballast could do that.

Why is it the philips ballast has all these extra features and none of the other one's do? Welthink used to have a dimmable version but haven't seen it online lately.

 

[Scrappy-doo]

I'm liking those socket converters AM. They look perfect for placing the bulb where a 600 would normally sit.

 

[beta]

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[willowz]

I'm still having a tough time finding a tent that will be a good fit for 2x of the Phantom 315s with air-cooled hoods. I think 3'x6' would be perfect but I can't find any tents close enough to that size. 4'x8' seems way too big (and tougher to tuck away in a dark corner of the basement), and 2'x4' is obviously way too small.

Am I going to have to custom build something? It needs to be stealth or easy / quick to break down, so all of the custom built options I can think of are out of the question. It's time to get moving on something and I reeeeeeeally don't want to deal with the added cost, complexity, and loss of cross light that running two seperate 3'x3' tents would cause so I'm pretty desperate for ideas at this point. Any suggestions out there?

Buy a actual large enough camping tent and then outfit the inside with the desires specifications that would maximize cross lighting benefit. But, is that benefit really worth going through that hassle?

Thanks.

 

[willowz]

For small personal grows (non-commercial) (my needs) I don't think the DimLux 630W Dual fixture + 1 x Philips Agro + 1 x Philips 942 4200K (both bulbs used throughout the whole grow), can be beat? Any suggestions?

 

[willowz]

I also say this because the DimLux has built in features that maintain the bulb over time. Meaning, they have a lot of experience built into the design, longevity, and maintenance of equipment.

 

[frostqueen]

I also say this because the DimLux has built in features that maintain the bulb over time. Meaning, they have a lot of experience built into the design, longevity, and maintenance of equipment.

Am I missing something? Why are you so worried about bulb life when they last for 3-5 years? And are only a $75 replacement?

I like the DimLux 630 idea for a single-light option in situations like yours. In a 4x4 or 5x5 tent or cabinet that would work out great I bet. The other option might be two Phantom setups in a 3 x 6 tent or cabinet. About the same price either way.

I've been told at a local shop that dimming CMH bulbs skews the output spectrum quite a bit. Does anyone here know anything about that?

 

[rives]

I'm still having a tough time finding a tent that will be a good fit for 2x of the Phantom 315s with air-cooled hoods. I think 3'x6' would be perfect but I can't find any tents close enough to that size. 4'x8' seems way too big (and tougher to tuck away in a dark corner of the basement), and 2'x4' is obviously way too small.

The closest that I can find is this one. The 80L is 2'-7" x 4'-11" x 6'-7". I've been using a GL80 (2'7" - 2'-7") for almost 5 years now and it has been a great tent. In most ways, I prefer it over my Secret Jardin 120.


http://www.ehydroponics.com/growlab-80l.html

 

[rives]

I've been told at a local shop that dimming CMH bulbs skews the output spectrum quite a bit. Does anyone here know anything about that?

The Philips literature states that dimming will alter the spectrum, but I've never seen anything that tries to quantify the extent.

 

[Hammerhead]

There's a common misconception regarding those, don't know if you know. 600w is HPS only, and MHs are conversion bulbs made for HPS systems -- like the CMHs made to retrofit into 400w MH systems. Not the same difference in performance you'd see between HPS and MH in the 250, 400, and 1000w segments. I don't think conversion-type bulbs, or dual-arc bulbs for that matter, are ever as capable as what they are made to replace. I assume they include a component that creates a loss.

Yes I was aware of that. I started with a 400mh changed to 600mh. I had much better results with the 600mh conversion than I did with 400mh. I had a 1k but too much heat so dumped that setup.. 600 where/are the most efficient don't know if they still are. None of these lights are used to flower with. All of my flowering lights are Gavita/E-PAP 1k's. I pop in 1 4kMH DE into the center fixture at week 6 to help finish flowering.

 

[beta]

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[willowz]

The Philips literature states that dimming will alter the spectrum, but I've never seen anything that tries to quantify the extent.

SunPlix claims that dimming the bulb will increase the blue spectrum, whereas the higher temperatures will increase orange and red.

 

[rives]

Looks like that might be the one! Do you think I'd take a hit yield wise with 2'7"^2 per light instead of 3'^2 per light? Why do you prefer the Growlab? Do you have a 315W LEC in your GL80? Would you feel confident that you were maximizing space and efficiency running 2x air-cooled 315s in a GL80L?

Thanks for the recommendation!

I would doubt that you would see much difference in the yield, that is only a couple of inches on each side if you have the plants centered. I run 2 plants side-by-side across the 2'-7" dimension and the extra 5" doesn't seem like it would have much impact, particularly if nobody makes that size.

I prefer the zippers on the GL over the SJ, they work easier. The SJ zippers seem a little more heavy-duty, but they don't move freely and always seem on the verge of binding up.

The weight of the material is very similar with the GL perhaps being a tiny bit heavier.

I like the GL door design better - they use 2 doors with a center zipper, even on the GL80. The SJ is 4' wide and has a single door, and every time I open it the door flops in toward the plants because of the negative pressure from the fan. It is difficult to support and unzip, you have to remember to keep the zipper handles up on the top right, unzip down the side and across the bottom with the lower one, grab the door with your right hand, and unzip the top the top with your left.

The SJ has more ports for running various things through and each port has drawstring socks on both the inside and the outside of the tent. The GL has fewer access points and single socks. The number of ports may be related to the size difference, I haven't really checked out equivalent tents.

The internal framework of the SJ is a little bit more stout, but again, it may be related to tent size. The SJ, even thought it is larger, only came with 3 slide bars for the top to support hoods, filters, etc. The GL came with 4. The 3 for the SJ are all the same length and are meant to be run parallel to one another, the GL's are set up so that 2 bars run one way and 2 bars run the other (the hangers on 2 of them have are longer and drop below the bars that are at right angles to them). For me, this gave a little more flexibility.

Yes, I'm running a 315w in the GL80, but it is in a Bell 600 hood, not the LEC. I have run (2) of the Bells side-by-side in my SJ tent, and the 4' x 4' dimensions makes it a bit tight one way and not enough coverage the other. I think that the 80L would be a much better fit for both dimensions.

 

[Avenger]

I've been told at a local shop that dimming CMH bulbs skews the output spectrum quite a bit. Does anyone here know anything about that?

see this post:
https://www.icmag.com/ic/showpost.php?p=7137089&postcount=886

 

[frostqueen]

see this post:
https://www.icmag.com/ic/showpost.php?p=7137089&postcount=886

Thanks, guys! Great info. That isn't too drastic a spectrum shift, at least looking at that chart.

 

[frostqueen]

Here's an interesting tent-related hypothetical question: let's say you had two tents or cabinets with highly reflective or white walls. One is 48" x 48", the other is 32" x 32".

Generally speaking, 30-36" is a good ballpark footprint size for a single 315. If you were to hang a 315 in the center of each of the above tents, which would be better?

In the 32" tent you will have wall to wall canopy at full ppf; in the 48" tent (provided you stay within the 36" max footprint) you would also get major side lighting from the walls reflecting back onto the lower growth.

I'm just thinking out loud here. I really like the cycloptics idea of using your walls to channel light back in to the undergrowth.

 

[rives]

I run a 31" x 31" and a 48" X 48". I've run both one and two 315's in the 48". My experience is that a single fixture in both provides fairly equivalent results in overall weight but the 48" gives more numerous but smaller buds (usually run 3 or 4 plants in the small tent, ran 5 in the big one on this run). I had to keep the light further away on the 48" in order to cover the additional plants, and I think that is probably what caused the drop in size but I think that even if you kept the same plant number, you would see the same results - it's a long reach to the sidewalls and back to the plant. A tent somewhere in the middle might provide better results, the jump from 6.5 sq.ft. to 16 sq.ft. is pretty substantial. From the recommendations that I got, Cycloptics likes pretty dense light coverage and keeps the fixtures fairly close to the sidewalls.

 

[timmur]

One 315 in a 2.5' x 2.5' tent should be nearly ideal in terms of PPF.