This LED vs HPS grow will compare the Platinum Led P600 with a 600W HPS. I am very interested in LED grow lights and want to see how they perform. There are so many opposing opinions that it seems the only way to find out the truth is to try it.
My main interest is not saving power or even saving on replacement bulbs. The purpose of this LED vs HPS grow is to see if yields are comparable and if there is a difference in the quality of the cannabis grown.
Those that favor LED grow lights claim they get better trichome coverage, higher THC and better terpene production. This makes sense because there is less heat generated. I have often thought my lights might be cooking my buds.
Those that favor HID lighting claim they get higher yields from HPS and the buds are tighter. If yields are close there may be an advantage to using LED row lights because of the reduced cooling costs. The one thing I definitely don’t want is wispy buds or a lot of popcorn.
One common HPS vs LED argument is that the penetration of LED grow lights cant match that of an HPS grow light and therefore the buds will be smaller and looser.
I have seen beautiful buds grown by both methods. In the end I think results are more dependent on the grower than the lights themselves. To that end my yields have been good and quality has been excellent but because I am a closet grower heat is a big issue. With summer coming on it will be extremely hard to keep my temps down with HPS lighting.
The Grow Lights LED vs HPS
- 1 The Grow Lights LED vs HPS
- 2 The Grow Closet
- 3 The Strain – White OG from Karma Genetics
- 4 LED vs HPS Side by Side Grow Comparison
- 5 One Week Old White OG Seedlings
- 6 My Platinum LED P 600 Is Here
- 7 HPS VS LED Week 2
- 8 Week 3 HPS VS LED Comparison
- 9 Week 4 LED VS HPS Shoot Out
- 10 Week 5 For White OG LED vs HPS Comparison
- 11 Week 6 LED vs HPS White OG Grow
- 12 Week 7 LED vs HPS – Day 21 Of Flower
- 13 Week 8 600W HPS And Platinum P600 LED Par Testing
- 14 HPS vs LED Week 8 Pictures
- 15 LED VS HPS – White OG Week 9
- 16 Week 10 Time To Harvest
- 17 Post Harvest – Final Results Not In Yet But…
- 18 Final Yields LED vs HPS Comparison
- 19 What Does It All Mean? LED vs HPS – What’s Better?
The 600W HPS
The 600W HPS is being run off a 1000W Solis Tek digital ballast. It is in an Adjust a Wing medium reflector. I get good coverage with this set up and good yields. I am not that concerned about the power it uses but because I grow in a closet the heat it gives off is a concern.
I am currently using cheap IGrow bulbs in my 2 reflectors along with a Solis Tek splitter and they seem to work fine, but because I am only going to run one light I will use my Eye Hortilux 1000W bulb and dim it to 600 watts.
The Platinum LED P600
The Platinum LED P600 is being advertised as an 800 watt equivalent not a 600w replacement but LED manufacturers often exaggerate the performance of their grow lights so I wanted to go a bit bigger.
Also the 36″ length and the shape is a better fit for my grow room and matches the 3 x 3 coverage area for a 600 watt HPS bulb. I think I can compensate for any difference by running this light higher up.
Platinum Led Grow Light P600 Par Test
If you look closely at the floor of the grow tent it is marked into 6″ squares. If you look at the shape of the foot print the light actually makes you can definitely see the light is not as bright in the corners or the outside edges. This is why I went with a slightly larger grow light rather than the P450 which is billed as a 600w HPS replacement.
Grow Light Costs LED vs HPS
The HPS grow light set up I currently have would cost $354 on Amazon. That’s pretty affordable and you get a top quality digital ballast and bulb. The Adjust-a-wing is very light weight, easy to hang and spreads the light very nicely.
LED grow lights usually cost more than this HPS lighting system but if you are going with something like a Magnum Reflector the costs are not that different.
The Platinum P600 LED currently sells for $659 on Amazon. So the LED array is almost twice as much as my current set up, but supposedly delivers more light. That still remains to be seen though.
If you buy the Advanced Platinum Series P450 450w 12-band LED Grow Light which is a direct replacement for a 600w HPS it would cost you $539 currently. The price difference here is about $185 more but you would quickly make up the difference on your power and cooling bills. And if you go for a more expensive grow hood the P450 could cost you less.
With a LED vs HPS comparison it can be hard to compare apples to apples because there are a lot of things that come into play besides the initial purchase price.
I hope by the time this grow is over we both will know what is best for our growing situation.
The Grow Closet
My grow closet measures 2′ x 8′. It has 3 of my high pressure DIY Aeroponic totes in it. Each tote has 10 grow slots in it. Cooling is with a 6″ S&P fan. Space is very tight so I use 2 small tower fans for circulation.
I am thinking about finding a way to isolate the lights from each other but due to ventilation concerns it might not be possible. It might not even be desirable because it might be nice to see the effect of the blended light on my plants.
The Strain – White OG from Karma Genetics
I have grown White OG twice already so I am fairly familiar with it. However this time there will be a twist to it. My favorite cut is what I call the Spear Pheno because of the shape of its colas.
I have 30 of these started but they are fem seeds that I made accidentally. In other words I had some nanners. It was a mixed grow so I cant say they are 100% White OG because the pollen could have come from my Biker Kush plants too. All seeds came off my spear pheno though so that will hopefully be dominant.
I planted 33 seeds and germination was 100% but I got rid of 3 that were slow starters. I honestly did not expect to have this many seedlings. I may get rid of some more along the way. Hopefully most will look like the mom. She grows a long, dense top cola and nice sized lower buds too.
This is a straight 12/12 from seed grow and should be interesting.
LED vs HPS Side by Side Grow Comparison
I am waiting for my Platinum LED to come which should be less than a week so as soon as that happens the side by side grow will start.
Right now the seedlings are 6 days old from germination and under my HPS lights. Not much to see really but here is a picture of some. They are just starting their 2nd set of true leaves.
One Week Old White OG Seedlings
Things are moving along and seedlings are doing well. There was a mix up with my order so I still don’t have my LED yet but it should be here in the next few days. Right now they are under my 2 600w HPS lights with a 6500k CFL hanging down low for some blues. HPS are all the way up and there is still plenty of light for these little guys. Because I am using a splitter they actually run at 500w and not 600w. Here is a couple of pics taken 7 days later.
My Platinum LED P 600 Is Here
My LED arrived just before the end of week 1. It is bright as fuck, I can’t look at it without hurting my eyes. Also quite a bit heavier than I expected. According to specs it is 24 pounds.
I hung it way up high and the plants got about 3 hours of LED light yesterday. Today I moved it down to about 28″ and also moved the 600 watt HPS down to the same height.
Here are a few pics:
There is a bit of bleeding over from the 2 light sources. I am considering some sort of divider but I am afraid of cutting off air circulation so I may just leave it as is.
At this point the LED can go lower and closer to the plants but I want to acclimate them to the light slowly. The HPS is pretty much as low as I can go without causing heat stress so eventually it will be going higher and may bleed over more than I want it to.
Plants will be starting on their 2nd week of 12/12 tomorrow and I don’t really expect to see a lot of difference between the two lights just yet.
HPS VS LED Week 2
Well it is a full 2 weeks I guess, boy the time flew by. These ladies have only been under the LED for 3 days.
Temperatures are about 5 degrees cooler on the LED side but that really isn’t a big surprise. The LED plants look a bit stockier than the HPS ones and that really isn’t much of a surprise either.
I have hung some panda film between the 2 lights and so far so good. There is room above and below it so there will be cross ventilation. It does a good job of separating the light sources. Not sure how well it will work once my screen is in place though.
Anyway here are a few pictures at the end of week 2:
The HPS side is definitely taller and it also looks fuller at least from this angle. The real test will be when they start to flower. I expect that to start in the next week or two.
Week 3 HPS VS LED Comparison
Well plants are all under their individual lights now separated by the panda film. I now have 12 plants under each light. I may cull a few more and get it down to 20 because there are a few runts on both sides.
There has been an issue with stem breakage and I lost a couple of nice plants on both sides and repaired a few with duct tape. I am not really sure what causes this.
It may actually be genetic because I have never seen this on non OG strains. It does not appear to be a rot or fungus. The stems just develop a hard woody spot that is very brittle. They are top heavy and it strains this spot. It actually looks like the main stalk overgrew the stem just above the neoprene collar.
Well good thing I started extra plants for this side by side. I am actually a bit disappointed in this grow because it just seems to lack the vigor I would expect to see.
The HPS side looks better to me than the LED side at this point. It is taller which is to be expected being under an HPS but it also seems stockier which did surprise me. The seedlings are very close to starting to flower and stretch and the LED plants look to be a few days ahead of the HPS plants in this regard.
The White OG was given a heavy defoliation just before taking pictures. I want to give all the lower branches a chance to develop and being covered by fan leaves slows or stops them from growing.
Here are some pictures for week 3:
First the side under the Platinum P600
The tallest plant is 12″ right now. A few more pics of her.
Here is a few shots from the top. If you look carefully you can see they are ready to start flowering.
Here is the HPS side The tallest White OG is about 17 1/2 inches. Overall I think the HPS ladies are showing more vigor and look better but the LED lighting makes it much harder to really see and compare the plants. Next time I will switch off flowering and take pics in veg mode where there is a lot less red.
These ladies are now at 1000 ppm. I bumped up the nutes from around 600 ppm because they are getting ready to start flowering.
Week 4 LED VS HPS Shoot Out
I has been 4 weeks for these White OG ladies and they are starting to flower. The LED plants are a few days ahead of the HPS plants and the buds seem more developed.
I have removed a bunch of plants this week. I started with 32 and they are down to 20, 10 on each side. I got rid of any that had suffered from broken stems and tried to leave the largest best looking plants on both sides.
There is 1 plant under the HPS that is healthy but pretty short and a few smaller shorter plants on the LED side that seem behind the others.
On the other hand the HPS plants look better to me overall. They are about 6 inches taller than the LED girls and look larger and fuller. On the LED side the plants almost look stunted to me, at least in comparison. Internode spacing is much shorter but some leaves look much smaller too.
I may have had the lights too close to these ladies. There are no signs of bleaching or any kind of burning. I have moved the lights to about 16-18 inches above the plants from about 12 inches.
When you look at the pictures you can see the size difference clearly. The screen is 28 inches above the totes. The HPS girls are going through it now and the LED still has about 6 inches to go.
HPS Plants Week 4
Here are some shots of the 600w HPS plants. They are pushing through the netting today. Bud development seems slower than the LED plants but it looks like there are going to be more bud sites on them.
LED Plants Week 4
Here is the LED plants. You can see they are shorter and smaller. You cant even see the screen in these pics and the tallest plants have about 6 inches to go before they reach it.
Bud Shots Week 4
Here are some early flower bud shots. The LED plants are a few days ahead in the process but in the end I don’t think it will matter that much.
So far I think the HPS side seems to be doing better and looks healthier but maybe I just am not used to purple plants. I did try turning off the reds and using the veg setting for some pics but the camera did not seem to notice so everything is blurple. I may try some lights out pics next.
It is kind of hard to see what is going on under these lights and the light is deceptive. Your eyes don’t really pick up how bright the LEDs are because of the color, that is until you turn away and realize you are seeing spots!
Week 5 For White OG LED vs HPS Comparison
This is the end of week 5 for my White OG girls. This was a 12/12 from seed run and the flowers look small to me and I have to remind myself that this is really just the end of week 1 in flower.
The HPS Girls
The HPS has stretched much more than the LED girls. There is much more branching especially lower down. I have begun to lollipop them and remove a lot of small side branches that will never amount to much. The buds don’t look as solid as the ones on the LED side but I think there are more bud sites.
The tallest girls on the HPS side are easily a foot taller than the tallest LED girls.
Tallest pheno center
Taller pheno stacking
Shorter pheno developing nicely too
Lots of lollypopping and will probably have to go through these girls again soon.
Size differences are apparent even with an S1 of this strain.
Start of a nice top cola
White OG buds forming and stacking already on this girl.
The LED Girls
The LED plants are much smaller and more compact. The buds themselves look larger and are definitely more firm while the buds on the HPS side seem more wispy and less mature.
The plants on this side seem to be putting more energy into bud growth and less into growing so many side branches.
Temperatures on the LED side remain about 7 degrees cooler than the HPS side. I suspect some heat is drifting over from the HPS light. Today they are 74 degrees and the HPS side is 82 degrees.
White OG Plants with flowering and veg lights on Plants with just the Platinum LED veg lights on Nice bud Starting to stack
Another bud close upMuch shorter canopy on the LED plants
It will be interesting to see how things develop from this point forward. Last week I thought the HPS ladies looked better but this week I am not so sure. The buds on the LED side look much better to me and are nice and firm. With tall strains like OGs a tighter node spacing is a definite advantage especially if headroom is limited.
Week 6 LED vs HPS White OG Grow
Well week 6 is over and it is also the end of 2 weeks in flower. On the LED side most plants are ahead of the HPS girls as far as flowering goes. The buds are fuller and tighter while most of the HPS buds are wispy in comparison.
But the HPS girls are much larger and more vigorous and they make the LED girls look stunted by comparison. The LED colors fuck with your head. Much brighter than they first appear and it is hard to really see clearly under that light.
I am a bit surprised at the variation in plant heights on both sides considering these are S1 seeds.
HPS White OG Day 14 Of Flower
The HPS plants are much larger and have produced more side branching and more bud sites. I have thinned out the bottom again and removed a lot of bud sites on lower stems and branches because they will never get enough light to really size up. I will probably have to do it again before things are done.
My reflector is now up as high as it will go and I may need to do some neck breaking if the stretch continues much longer. I think it will end in about a week though.
White OG Upskirt.
Lots of difference in size.
White OG on the left looks promising
Tall girl with lots of bud sites
It’s a Jungle even with fan leaf removal
My favorite White OG on this side
Nice stacking starting.
HPS White OG Day 14 Of Flower doing its thing
My favorite White OG girl on this side
Another bud shot
And another cola starting
And still another cola starting
My favorite again.
LED White OG Day 14 Of Flower
The White OG under the LED lighting has much more compact growth than their HPS sisters. It seems to have much less vigorous growth and much less side branching. Internode spacing is much tighter and leaf size is smaller too.
I am a bit worried that I had the lights too close and may have caused some stunting although no bleaching has shown up. The Platinum P600 is very bright and throws a lot of light and seems to penetrate well even all the way down to the totes.
The buds themselves are much fuller and harder and this may be because the spectrum is making the plants put more energy into flowering than vegetative growth.
LED group shot week 2 of flower for White OG
The totem pole in the center is my favorite on the LED side
This is the spear pheno
One of the taller WOGS
Another nice WOG cola forming
Here is another taller WOG
Above are a few canopy shots. You can see a pile of fan leaves I removed on top of the tote but they wont be staying there long.
Nice buds forming
I see trichomes forming on the leaves already
Frost starting on this one too
Top bud on my fav
WOG Spear pheno
WOG Spear pheno again close up
Early frost warning
These ladies are starting to show signs of frost
Week 6 Final Thoughts
It is still to early to say which lighting system will win this comparison. My thoughts are that the HPS will win on weight simply because the plants are much larger. But right now it looks like the Platinum LED will win on bud quality. It also occurs to me that mixing both types of lighting may produce the best yields and quality of all.
Week 7 LED vs HPS – Day 21 Of Flower
Buds continue to size on both sides of the grow closet and week 3 of flower is coming to an end. The HPS girls are twice the size of my LED plants and are pretty scraggly looking.
The LED plants look like miniature versions of them but bud development is further along and although the other side has more buds they are smaller overall and not as dense. There is more resin development and better smell on the LED grow White OG plants.
I still think this LED vs HPS grow will turn out with the HPS yielding more simply because the plants are bigger. I wish I had done this run from identical clones but I really wanted to see what was in the White OG seeds I made.
The HPS Girls
The tall girl below is getting really close to the light. I wanted to supercrop her but I really want to see how her cola stacks naturally.
Here’s the HPS side of the grow closet.
HPS cola shots below. These are the 2 best and look the most like their mom.
The LED Girls
To my eye, the side of my grow closet with the White OG under the Platinum P600 looks much better. There is more bud development going on and a lot less energy going into wasted vegetative growth.
Full LED shot above and below. I think there will be some really top shelf buds coming from here. Front view of the Platinum LED side of the grow closet Short plant in center is my favorite so far and I took a cut from her in early flower which hopefully will take. The lady above is really stacked! She is the most like the original mom. Also nice and short. Some of the other girls are no slouches either. A few LED cola shots below.
Week 8 600W HPS And Platinum P600 LED Par Testing
I have been wanting to do some par testing on my HPS vs LED grow for a while but the Apogee par meter runs about $370 and I did not want to spend that much on a meter. I would rather spend that money on updating my lights themselves.
Fortunately I was able to get a deal on a Hydrofarm Quantum Par Meter which costs about $100 less and do some testing.
I am really glad I got this par meter and the results I got were really surprising.
First PAR stands for photosynthetically active radiation. To dumb this down to plain language this is the wavelength of light from 400 -700 nm. that plants use to grow.
Because LEDs use optics I did not want to rely on a single reading. Any LED manufacturer can put a par meter under a tight beam and get amazingly high PAR readings.
But that is a false reading because the reading 6 inches away may only be half that and plants cover a much larger area. Also readings are highest under the central core of the lights footprint and this is true not just for LEDs but also for HPS lighting as well.
I could not find a par footprint for a 600W HPS bulb although there are many for 1000w bulbs. What I was able to find was par ratings for a 600 watt bulb range between about 800-1000.
Below is a par map for a 1000w Gavita Pro DE. These are probably the most efficient HPS lights available and what most commercial growers use. To be honest at $489 each I would use them too except that they put off so much heat you need 11 foot ceilings to use them. So not really an option for most of us.
Anyway, what you want to do is average all those points and that will give you your PPF or photosynthetic photon flux. You want to know PPFD or photosynthetic photon flux density because this gives you the light intensity falling on your plants as active photons. This is the actual amount of light your plants have for growth. So as an analogy a PAR reading tells you how hard it is raining and a PPFD reading tells you how much rain is actually falling.
So I raised both grow lights to 24 inches above my screen measured from the bottom of the reflector. The HPS bulb was actually about 28 inches above it because the Adjust a wing is bowed.
It is hard to take readings when their are plants in the screen and the meter does not give a stable reading, it goes up and down within a range. So this is not an exact science but I tried to use the middle or average range.
To get the PPFD you have to convert your space to a percent of a square meter. I am going to assume each side is 4 x 2 and my math says 8 sq ft as % sq m = 74.322432 so I am using .743 as a multiplier.
I will post all my par readings in another post because this one is long already and because I am also testing some COB LED grow lights and want to include them too.
You can check this grow out at: https://420dotcom.com/karmarado-strain.html. As you can see the canopy is so dense it won’t be possible to take meaningful par footprint readings at this time.
600W HPS PPFD Readings
Here are the readings from the HPS in my Adjust A Wing Medium reflector.
600 W [email protected] 28″ AVG PPF 234 PPFD = 173.8
600W [email protected] 12″ AVG PPF 653 PPFD = 485.1
Results were surprising to me. I thought these would test much higher. Numbers were very similar to the Gavita at 36 inches. I noticed that there seemed to be a lot less light on the socket side of the reflector. My taller plants are in the 12″ range although I had one get to withing a few inches of the bulb and had to supercrop her.
Platinum P600W PPFD Readings
The PLATINUM LED P600 @ 24″ had an avg PPF of 606. PPFD = 450.2
Overall the individual PAR numbers were much higher than the 600W HPS at 24 inches, with a PPF more than double. You would have to run the HPS at 12″ height to compete and running it that close is not really practical. The P600 was very similar to the readings for the Gavita at 24 inches.
At 18″ the core readings were double that of the Gavita and my plants experienced bleaching.
Full Gavita footprint PPF was 619.8 in a 4×4 area. I am assuming they ran it at 1150w so that makes comparison to a 600 or 1000w HPS difficult. Multiplying by 1.48 the % of a square meter:
PPFD = 917.3 So the Gavita is the best light in delivering photons but unfortunately most of us cant use it at full power and would have to run it at lower wattage.
Week 8 Final Thoughts
The P600 Platinum LED is an extremely potent light. It’s long narrow shape allows lights to be placed in rows over a 4′ wide grow and the shape seems to have more uniform coverage in the core area of the grow.
I believe this light is a better choice than the 600W HPS and even comes close to the Gavita in par output without all the heat problems.
The Gavita tested just slightly higher than the Platinum LED, 619 vs 606 but that was with a full 4×4 footprint while my other readings were based on a 2 x 4 footprint. When I extracted a 2×4 slice of that footprint the PPF was 596, actually slightly lower than the P600’s 606.
There are still several weeks to go on this LED vs HPS side by side. I don’t think that the Platinum will win on yield due to grower error.
I had the light way too close early on and I think the plants were stunted. I moved the light up but still had bleaching occur on my top colas. These lights are really very powerful and they do cover the area very well. I was concerned when they did not show a complete footprint and only a center point but my fears have been put to rest.
Definitely recommend these lights but next time I will keep them much higher up.
HPS vs LED Week 8 Pictures
White OG HPS Girls – Week 8
Growing nice spike colas like their momma. One was just inches from the light which is on the ceiling. Had to bring her down a notch, would have loved to leave her standing.
I hated to break this one back!
White OG LED girls – Week 8
Too much of a good thing! The Platinum P600 is crazy powerful and I didn’t raise it fast enough! So there is bleaching on the tallest top colas now and one a bit lower started to foxtail.
I got a PAR reading of 2460 at the top of my tallest cola. Summer sun is about 1000-1500. No wonder she bleached!
This one has the worst bleaching. Nice foxtailing. Snow on the mountain? Nope. Bleaching. Lots of nice lower buds forming under the trellis. Pretty lower bud almost looks ready to harvest.
LED VS HPS – White OG Week 9
This is week 9 of a 12/12 from seed grow with White OG. These girls have been in flower for about 6 weeks now.
White OG – HPS
The White OG under the HPS has stretched a lot. One large cola was growing right under the back of the bulb and was within a few inches from the light itself. I did not want to but I had to supercrop her and she is now laying across the screen now.
These girls are much bigger than the LED plants and the colas are larger too. However these buds are much looser and airier and sometimes size can be deceptive.
White OG – LED
These plants are smaller, about half the size of the others. But the buds are much denser and well ahead of the HPS plants.
I am noticing that there are hard individual round buds on these and the flowers have the look of bud clusters instead of lots of loose pistils.
The LED plants look like they will be ready way before the HPS girls. Buds will be smaller and more dense. Maybe they will be close in weight to the HPS even though they are smaller.
Normally this is a 10 week strain but because it was straight 12/12 I think both sides will need an extra week or 2 to mature.
Week 10 Time To Harvest
It is week 10 and it is harvest time. Today is 70 days from flip on this 12/12 from seed grow. This strain normally goes 9 or 10 weeks depending on pheno.
The White OG under the Platinum P600 LED looks ready to harvest. The girls under the 600w HPS actually look like they could go longer.
Since this is a side by side how fast plants reach maturity is an evaluation factor. I honestly don’t know which side will win as far as weight goes but the LED grown buds are definitely tighter and harder.
Looking forward to the weigh off. Looks can be deceptive and the LED plants are definitely smaller and colas are not as large but they are packed with buds from top to bottom.
The HPS grown plants are much larger but all the buds are concentrated above the screen. The colas are nice sized but have a lot more young pistils on them.
I am going to give both sides 2 days of darkness before harvesting to give the HPS plants a bit more time to ripen. Trichomes are mostly cloudy on them but there is some amber on the LED plants.
White OG Under 600w HPS
These ladies made a messy leggy canopy and some had to be broken back because they were too close to the light. They also produced some arm sized colas and a few seemed like they had much later maturity.
White OG Under Platinum P600 – 345 watts
Compared to the HPS these plants are much tidier. They are smaller plants and produced harder buds from top to bottom. They definitely matured faster.
Week 10 Final Thoughts
Some of the size difference between plants may be grower error. I bleached several tops with too much light. I did not have a par meter at the start of this grow and it turned out these girls were getting about 2400 umols which is twice what they should have gotten.
Chalk one up to grower experience. This was my first grow with LEDs and I underestimated their power. With HPS you worry about plants getting burned by too much heat but plants getting too much light is a new concept for me.
Post Harvest – Final Results Not In Yet But…
This week I harvested and trimmed my buds. I always green trim and take the buds off and spread them to dry. I cant remember the last time I hung my plants.
I don’t have final weights yet but I can tell you that the HPS yielded more, but it was a hollow victory that could have gone either way.
LED buds left, HPS buds right LED HPS
What’s Wrong With This Grow?
First I have to say this is a flawed side by side caused by operator error. I should have used clones instead of seeds. I thought my S1 seeds would be fairly uniform. I tried to evenly divide the plants between both sides but I failed.
There was widespread differences in yield and size although they almost all had the spear cola shape. Like I said I should have used clones!
Secondly I kept the Platinum too close and stunted the LED plants. They were getting twice the par they should have. 1000-1500 is all plants can handle unless they are getting additional CO2, which they weren’t. They were getting 2400+ because the light was to close so they bleached and stunted.
LED vs HPS General Observations
The Platinum P600 pulls 345 watts at the wall and the HPS pulls 600 or a bit more. The manufacturer claims it can replace 800w of HPS but to me that is doubtful. Most LED makers seem to exaggerate the replacement power of their lights.
I have done a lot of searching about this and come up empty handed. No definitive answers any where. I read that HPS is about 35 % light and 65% heat. LED lighting is the reverse. About 65% efficient and 35% heat. But depending on chips used and how hard they are driven it can be only 50% efficient and I would bet some cheap Chinese LEDs are below that.
So my best guess is if you have a good quality LED or COB you can reduce your HPS watts by 35% you will have the replacement wattage you need. So for a 1000w HPS replacement:
1000 x .35 = 1000-350 = 650w LED
800 x .35 = 800-280 = 520
600 x .35 = 600-210 = 390
So you can see the P600 falls short of a 600w replacement and certainly can’t replace 800 watts. Of course this is an oversimplification because spectrum also plays a role and so does actual par.
But you are not going to replace a 1000w HPS with a 100 watt UFO. I think you need to be around 50-75% of the wattage you are replacing. The Platinum P600 LED is a good light with high par readings but I think it is a 500w HPS replacement. I am glad I went a size larger. I have seen great numbers from the P450 but compared to 600 w of HPS I think the results would be disappointing. Savings is not so much in electricity but in the amount of heat you need to remove.
Both sides had healthy aeroponic roots with lots of fishbones. Root size was about the same for both sides.
The HPS buds generally were larger and were very hairy. There were lots of big pistils on the buds.
The LED buds were smaller but harder and better formed with less pistils and more developed individual buds.
The LED buds were earlier. The HPS side was almost a week behind. Both sides had stopped drinking and had cloudy trichomes by the end of week 10. I gave the HPS girls an extra 4 days to catch up before harvest.
Trichome coverage and stickiness was about the same.
There was way more larf on the HPS plants and 3 plants really did not produce anything. They were overshadowed by the larger plants.
The largest plant was on the HPS side. It was closest to its mama which bore 75 grams. I weighed it green at 255 grams. I have found my plants will weigh 30% of their green weight when dried to 60% relative humidity. So this plant will produce about 76.5 grams dry. It was the only one out of 20 plants that went this high and it ended up on the HPS side which is why the HPS will win. If it had been on the LED side results would have been different.
The remaining plants were in the 100-150 grams green range except for the 3 HPS plants under 10,30 and 45 grams that were almost total larf. The highest yielding LED plant was at 150 grams green. All the LED plants produced usable bud. There was some larf but nothing like on the HPS side.
I will post final numbers once everything has dried.
Final Yields LED vs HPS Comparison
So everything is dry now and the here are the LED plants. The bag weighs 10 grams so the Platinum LED produced 155 grams or 5.5 ounces.
The 600w HPS side produced 175 grams or 6.25 ounces. So 20 grams more than the LED. I don’t know if you can tell from the pics because I squeezed the bag some, but the buds are looser and the bag is much fuller proportionally.
What Does It All Mean? LED vs HPS – What’s Better?
I know the HPS produced more bud. It was not as firm as the LED buds and it used almost twice the wattage to pull only 20 more grams.
Total yield was 11.75 ounces or 330 grams for both sides.
The HPS had the biggest plant in the grow but also the most plants, about 4, that produced next to nothing. Total GPW 0.29
The LED pulls 345 watts and gave 0.45 GPW. Plants were smaller but budded up nice and there was less larf on them.
Not my best grow for sure but there was a lot of variation between plants. Both sides produced some nice buds and have good resin production and smell. The potency of this strain is very high and since I am not testing it would be hard to say one is better.
In short the HPS won on total weight, but not by much. It used a lot more juice to do it. GPW were much lower so it is obviously the less efficient light. It also gives off a lot more heat and I think bud quality is lower due to the heat.
I am convinced LED is the way to go. The only really advantage I see to HID lighting is the start up price. The lower purchase price will get eaten up by bulb replacement costs, higher electric bills and higher venting and cooling costs.
LED Trichome Shots
HPS Bud Shots
HPS Trichome Shots