Hello Grasscity blades! I'm going to be doing a grow comparing these lights, all parameters of the grow will be kept as identical as possible, except the lighting source. Most measurements will be in US units, but I'll try to remember to make the conversions for you folks that use the metric system. Conversions will be rounded to the nearest whole number, or even decimal. For example, 10.4cm will be rounded to 10.5cm. 10.29cm will be rounded to 10.25cm. First off, we'll be growing in a Gorilla Grow Lite, 24x48x79" 61x122x200.5cm, with a divider installed in the middle, making it two equal 24x24 61x61cm areas with shared ventilation at the top 12" 30.5cm of the tent. Ventilation will be provided by a variable speed Ventech 6" 15.25cm fan and filter, rated at 440CFM 12.5 Cubic meters/min We'll be starting our seeds in small 3" 7.75cm pots, up pot into 1gal 3.75L, then up pot into the final 7 gal 26.5L containers, but we'll only be using 6 gal 22.75L of medium to leave some space at the top. Soil will be my own mix, we're using a 5:1 ratio of soilerlite, with about 5% Coco coir for improved drainage and increased O2 levels at the root zone. Nutrients will be the full line of Humboldt County's Own (Except Purple Maxx since we're not growing a purple pheno). And of course we'll be growing Dr Krippling Incredible Bulk This is a Feminized photo strain. Now onto our lighting, since that's what we'll be comparing here. We'll be using a Mars Hydro 100x3 Mars is a full spectrum light, so we'll be growing with everything Mars has to offer from seed to harvest. Mars lists a 150-170w draw, which gives us somewhere between 37.5-42.5 watts per square foot. We'll be using a Platinum LED P300 Platinum has Veg and Bloom switches, so we'll be using the Veg cycle from seed to flip, and we'll be using full spectrum from our P300 after the flip. Platinum lists a 93w draw in Veg, which gives us 23.25 watts per square foot. Platinum lists a 185w draw in Bloom (full spectrum), which gives us 46.25 watts per square foot. Both lights are using 100 diodes, and are pretty much on par with each other on paper. We'll be vegging under the more common 18/6 light cycle, and flower will be done under the more common 12/12 light cycle. Both lights will be operated by the same timer as well, to ensure the on/off cycles are identical.
I'd also ask that there not be any arguing over which is better, or arguing that HPS is better, etc.. I have both lights. I got my Mars last year, and got the Platinum this year, and was curious how they'd perform side by side, since they're both pretty equal in specs. Discussions/questions about the grow are welcome, but lets try to keep it on topic! If you'd like to chit chat, you're welcome to visit my Failboat journal in my signature! Lets get into specifics of the environment now. Ambient room temp sits between 68-72 F, or 20-22.25 C. Ambient room RH sits around 45-55%. I have two digital thermometer/hygrometers on the way now, and will take tent readings when these units arrive. Current tent temperature is 75 F or 24 C. And this is usually the hottest the tent ever gets. On to the tent, some measurements, and other details. The tent has been divided in half exactly, using a wood frame, covered in 4 layers of white tarp material. The pots are all identical as well. Here's the P300 side: And the Mars side: Mars lists the germination light distance at 24-30" 61-76cm, Vegetative light distance at 18-24" 45.75-61cm, Flowering light distance at 12-18" 30.5-45.75cm Platinum does not list specific growing distances on their site, so I'll be starting both at 26" 66cm, and will make adjustments as needed if we see any bleaching. Platinum: Mars: UPDATED INFO AS OF AUGUST 1st: In a perfect world, the plants would remain the same heights, as would light distances, resulting in a truly perfect comparison. However, we all know plants will all grow at their own rates, and the lights themselves can cause a variation in growth as well. We're going to start with 26" 66cm, but we're going to give the plants a little freedom to grow as close as they want to the lights, but I have decided that following the ranges listed by Mars will probably be the most fair to also show intensity, and penetration as well. Most specifically, if we see any stretching or bleaching, we'll give a plant a slightly closer, or further light, allowing the light to perform at a more optimum distance for the plant, but only within the listed ranges for each stage of growth. I think this will be a happy medium between comparing intensity and penetration, while still allowing both lights to operate at optimum distances within the given range. If the plants end up needing varied light distances, we will include measurements in every update as well, so everyone can see what the plants are doing, and what keeps them happy under each brand of light.
Nm I over read it. I'm really interested to see that part. Veg only vs full blown panel. Stretch node spacing etc..
I thought I should use both lights as they were intended to be used, to keep things interesting. So basically on paper, during Veg (18/6) we're going to see a comparison of 93w draw Veg spectrum Platinum vs. 150-170w draw full spectrum Mars. When I flip to 12/12, we'll be seeing 185w draw full spectrum Platinum vs. 150-170w draw full spectrum Mars. During Veg, Mars has a 57-77 watt advantage. During Flower, Platinum will have a 15-35 watt advantage.
Welcome aboard everyone! Today is day 3 of germination, and nothing breaking ground yet. My germination method does not involve soaking or paper towels (I would likely damage a taproot upon transplant), instead, I prefer scarification. It's a simple process that involves lightly scratching the testa, or seed coat, through various methods, depending on the seed you're germinating. Some seeds have a tougher testa than others and require serious scraping/scratching. For Cannabis seeds, I use a foam center or thin wood nail file (It has to be flexible to prevent too much force from being applied) on the fine grit side, and just use it to roll the seed back and forth in my hand 5 times. You want the seed to roll, if it remains stationary you can take too much off, and actually damage the seed. Once that is complete, I plant taproot down into my medium of choice, which in this case is soil. Then just keep it moist, but not soaking wet. I typically plant about 3/4-1" 1.9-2.5cm down, and usually see sprouts in about 5 days. Digital themometer/hygrometers should be arriving today, I'll get some readings on those this evening after they've been set up in the tent.
Meters are in. I'm in the middle of installing a new gas tank for my truck, so I don't have the full baseline properly done, I'll get a good baseline tomorrow. I left the meters in for several hours, and just opened the tent and got these readings: PlatinumLED: 47% 72.5F Mars-Hydro: 52% 76.8F I then switched the meters between sides, and left them in for 10 minutes, and got these readings: PlatinumLED: 49% 74.5F Mars-Hydro: 59% 75F Temperatures seem to be accurate within 1 degree. Humidity has a bit of a variation to it. I'm going to take a few readings tomorrow and see what we get, just to establish some sort of baseline. I will switch meters back and forth between sides as well, just to make sure I'm getting a good average reading. But so far it looks like the PlatinumLED runs a little cooler than the Mars. But this is just Veg spectrum on the platinum vs. full spectrum on the Mars.
1 hour later I took some readings again: PlatinumLED: 54% 70.5F Mars-Hydro: 55% 77.7F I'll continue monitoring in 1 hour intervals tomorrow, and will continue switching the meters back and forth. Have a great night everyone!
At 8:00 am within seconds of opening the tent: PlatinumLED: 47% 72.8F Mars-Hydro: 65% 78.6F I gave both pots a watering, a little more on the Platinum side, as she seems to dry out faster. The soil on the Mars side stays moist longer, so I want to see if an increase in watering to Platinum's pots will help increase the lower RH levels that I'm seeing. No water levels given will flood either pot, as I have excellent drainage with my soil/perlite/coco mixture, so we won't see any slow growth or slow emergence. On the topic of emerging seedlings, today is day 4 of germination, and after watering I was able to see the loop from the stem on the Mars side, nothing visible on Platinum's side yet. I have switched the meters again, will close up the tent for a few hours, then come back and take another reading, and see what we can see with the seedlings. EDIT: 1.5 hours later: Platinum: 57% 70F Mars: 58% 78.6F
I agree, I think once I flip the bloom switch, we'll see temps equalize. RH has evened out pretty much too. Right now I see 64% on the Platinum side, and 57% on the Mars side. And it looks like both seedlings will be emerging today also, which is really cool to have them pop on the same day, it makes things that much more even for the comparison. PlatinumLED Bulk is just visible at the surface now, wearing her fancy seed helmet: Mars-Hydro Bulk has emerged without a helmet and is ready to get things started:
