OK, just looking for a few pointers. Have done a wee bit of research and like the look of these. But there's way too many options...cheap ones worry me, and expensive ones worry my CC. 315w vs 630W ? 3k vs 4k ? Single or double ended bulbs ? Built in ballasts vs separate ballasts ? Best reflectors ? I like to try and keep things as simple as possible, less things to go wrong. Looking at a 1 m2 grow, or thereabouts. Any, and all suggestions would be appreciated.

Hi all, Hope your all having a good christmas. Just got the loft build sorted and now onto the kit. I have a few questions on light in the veg and flower. My space is 1.2x2.4 and plan on having 8 in Autopots. Ive been to a shop today to have a look at lights ect and the guy in there has advised x2 600w HPS with a Maxibright Horizon CDM 315w for supplemental lighting thats sits in between, this light covers a 1.2x2.4 tent. My question is, the CDM is mainly for the veg and the first few weeks of flower right (UVA, UVB), so after that i can turn it off in flower and leave just the HPS for flower?? And second, if i have the CDM on in veg can i turn my x2 600w HPS down to say 400w in veg without comprising growth ect?? Cheers

Hi guys, Im upscaling my grow from a tent to a room. Im hoping to put 4 lights in, i already have 2x600w HPS.. but would my 8” 1008m3/h extraction be enough? I cant find a calculation. My room has a calculated volume of 12.6m3. More light = more heat ..weep tia

Help needed! Currently I am using 400W HSP in a 0.80 x 0.80 x 1.60 m (approx. 2.6 x 2.6 x 5 ft) tent. But I want to switch to CMH/CDM/LEC. After a lot of reading, I decided to start with a Philips 315W 930 Agro for veg. and flower. But I need help to find the right one. Suppliers simply use the same terms for different types of lamps, see the list. But usually they don't show pictures of the box or the type printed on the bulb. How can I be sure I'm buying the right one? Can someone explain what to look for? As far as I understand the box and Bulb should both state "Greenpower" and "CDM-TP", see image. Is this correct? Thanks, Tracker06 Picture found on the internet

Well i'm not happy at all with these CMH lights, the 942 Daylight lamp has just died after only around 3600 hours of use! Luckily i went into the growroom just before the light was due to come on as i took some pictures to update my grow diary, pics took the light came on and as soon as it got to its full brightness it suddenly went off. I did not touch anything and waited for the bulb to cool, not long as it had only just come on. Looking at the lamp from underneath i could see a brown mark on the ball thingy inside the the lap so i unscrewed it. I put my 930 Agro lamp in and the light came on perfectly and stayed on. The 942 lamp is obviously blown or something, i cant say that brown patch was there before but it looks suspicious, i do know it does not work now and not happy at all as these lamps cost around £100 each last time i checked. I purchased the whole CMH kit back in 2017 but the 942 lamp has only had around 3600 hours of use i'd say. I've done around 5 grows with it, i use T5 lighting for the first couple of weeks and average 4 weeks of 942 lamp veg, then maybe up to a couple of weeks under the 942 at the start of flowering... So thats roughly 28 days of 20hrs use which is 560hrs, 14 days of 12hrs = 168 so total average for a grow 728hrs.. 5 grows use is only 3640hrs use and they say the average life of these lamps are 20,000 hrs! Has anyone else had one of these lamps die prematurely? Looking at the box of the 942 lamp it says manafactured in 2016 although i did not purchase it until mid 2017. I suppose i can't do anything about it now as Philips or the growshop would not interested. I'm just glad i was in the growroom as it was due to come on and i saw it go off after a couple of minutes. The plants are at Day 7 into flowe so the 930 Agro was due to go in there soon anyhow. Thing is, now i'm expecting the 930 to go soon too as its not had so many hours use yet. Here a picture of my CMH kit and both lamps. > See the brown mark on the bulbous thing? >

Has anyone seen the latest 630w and 945w cmh lamps? They don't appear to available in the UK yet but they both appear to be very interesting. 2000umol for the 945w and amazing spectrum. I do hope Philips decides to do a version.

Hi All, its been a while since I posted here though I do check in regularly to keep in touch. Apologies if this is a long post. Hii all, I’ve been getting over 1g/w consistently for the last few grows using 4 x cdm in maxibright twin reflectors in the 1.2 x 2.4 tent and 2 x cdm in focus x 1.2 tent. Been changing the lamps from 942’s to 930”S as needed. Just recently changed out all the 942’s to 930’s for flowering and discovered that 2 of the 930’s didn’t fire up - upon closer inspection one was ‘cloudy inside and one appeared fine. No idea why as the others are all working fine- oh well. Also recently got an Apogee MQ500 to check par levels. In the tents, lights are hung to give a fairly even 750 umols for early flower (lowering the lights to give approx 850- 900 later in flower), but I was amazed when checking the sunlight last week that the outdoor light levels were about 2,000 umols. No wonder the outdoor girls are romping away so well! so, in the search for perfection, I’ve hung a new 942 (to add a little more blue spectrum) in the centre of the large tent with the 942 in a horizon reflector which is designed to give a fairly even coverage of 1.2 x 2.4 making a total of five x 315 cdm’s for that tent. Overkill? I’d also like to put an additional light in the centre of the 1.2 x 1.2 tent - possibly a QB for improved canopy penetration - the 135w HLG quantum board might be ok at 3500k - the 265w is probably well over the top (as would probably be an additional 315 cdm). Any opinions? Anyway, and on a different topic, after this year’s faffing about with our Saharan summer weather, I’m thinking of a totally closed loop system for next year if funds will permit. Thinking of a split air-source heat pump Opticlimate at running at 30c with co2 supplementation. Has anybody used this system. Thanks again to all at 420 for this amazing community resource.

Looking to upgrade my 1.2 tent to a 1.5 next grow. Also want to upgrade my light, currently running a 600w hps with a battered old adjusta wing reflector I was given to get me started. Looking to get either a 1000w air cooled hood with an adjustable ballast or 3 315w cmh’s. I’ve read that cmh lights run cooler than hps.. My question is, will the 3 cmhs give off less heat than the air cooled 1000w? I’ve struggled with my temps on these hot days we’ve been having. Can’t turn the extraction up anymore due to noise (can hear the neighbors talking through the walls!) so need to find other ways to keep temps down. I understand with the 1000w I probably will have to run it at 600 or even 400 at times. Do they do adjustable ballasts for the cmhs as well? I’ve not looked too much into them due to cost tbh, but will stretch some how if it means keeping my temps good! Any help or advice on the lights or how to keep temps down in summer would be much appreciated

hi guys, so, my big old gavita 1000 needs the bulb replacing and im wondering if its worth dropping the cash on a DE or just going CMH. my mate just finished his first grow with CMH and was really impressed. im running a 1.2m2 tent which is twice his size. i seem to have had issues in the past with the gavita producing too much heat even though i have a decent extraction. i know i will be reducing my actual light output but i think with the much lower temps i might not see too much negative affect. its only for my own consumption anyway. and i guess i could always add another light easily enough. i normally veg for a couple of weeks under a 250 MH so would it be worth even buying the veg lamp and just go with the agro lamp? is the maxibright setup the best? or is it worth spending a little more on the LEC? my local grow shop has these 2 deals: Maxi bright Daylight Digital 315w CDM Single Kit Maxi bright Daylight digital 315w CDM Single Kit uses an advanced electronic ballast to power the Philips MASTERColour CDM-TMW Elite 315W EL and Philips MASTERColour CDM- TMW Elite Agro 315W EL lamps for excellent PAR output from the lamp per watt of power consumed. £239.95 Maxi bright Daylight Digital 315w CDM Single Kit + Lec 315 Reflector Maxi bright Daylight Digital 315w CDM Single Kit + Lec 315 Reflector uses an advanced electronic ballast to power the Philips MASTERColour CDM-TMW Elite 315W EL and Philips MASTERColour CDM- TMW Elite Agro 315W EL lamps for excellent PAR output from the lamp per watt of power consumed. £329.95

Have the above space and wanted to no if it would be possible and if not and only 2 315cmh would be best would I be better going with 2 315cmh or 1 630cmh for my space

Alright guys! I'm getting rid of my 1.2m tent for a bult wooden groom in its place. I have a dilema though! I am going to have 2 x Ceramic metal halide dimmed to 250w and 1 x 250w hps in the middle. My plan is to nail/screw all three reflectors to a plank of wood so they can all be raised and lowered a the same time... the question is how do I raise them from the door as I won't be able to get to the back once plants are flowering. here is a diagram of the layout of the venting, all simple no problem there. here is a diagram of the reflectors at their highest position and at the lowest position. I have thought about using a electric winch but I am out of my depth loking at them. I did find one electric winch made for raising and lowering lights made by sunsytem but they no longer produce them, and the only ones left are in america... I did think of a manual winch but apperently they are not suitable for lifting weights over head. If anybody has any experience on what manual winch is suitable or an electric one! Or any ideas people may have. If I have not been clear please just ask and i will try to clear it up. thanks in advanced FC