ViparSpectra XS1500 LED Grow Light

Germination update -- #2 sprouted Jan 20 #1 sprouted Jan 21 re-planted #3... twice, third time is the charm it turns out. Fertilize first irrigation and on with 10% or more runoff. I don't feed heavily. It merely maintains a consistently fertile environement. So, what went wrong? Tap water change pH out of nowhere from a steady 8.4 to ~7. Add to that the new substrate i mixed up is more acidic than expected. These two factors comounded for a pH near or below 5. Third seed was given a proper environemnt and it sprouted in a healthy manner. This was laziness, but positive note is i am re-stocked on pH strips. Had just enough to test tap and runoff of a few pots. I've gone back to a promix / vermiculte mix. Four parts of the promix BX and three parts extra coars vermiculite. This ends up being the 50/50 peat : vermiculite+perlite ratio that i want. It's fluffier, it holds more water, pH balanced, and i don't have to do anything but mix it up. KISS - i deviated without significant potential for benefit. very stupid About grow: Some autoflowers in max PPFD relative to ambient environment -- I do not control for VPD nor add CO2. I do avoid any temps below 68F. We'll go seed-to-harvest under a ViparSpectra XS1500 LED grow light in a 36" by 36" by 60" grow tent. Seeds were sown directly into substrate. A simply mix of sphagnum and vermiculte, so this is a Soilless grow. It makes use of simple methods. I fertilize the same mix of balanced nutes from beginning until the end with 10% or greater runoff. Runoff goes down drain, or I toss it outside in warmer months. This maintains proper concentrations in the substrate. Each time i fertilize, it resets this concentration as long as I adhere to the excess runoff to waste. Virtually impossible to overwater or overnute a plant if you stick to a simple wet-dry cycle. Top inch or so dries before I repeat irrigation. Keeps roots driving down to moister areas insted of the surface and helps avoid pests and bad microbial growth to some extent. These are not guarnatees but related to probability and risk. I will react to any individual plant's needs in regard to nutrients. Minor adjustments might be made per plant based on how it reacts. Few plants operate outside of a normal balanced mix. My lack of environmental control does inevitably lead to a slightly ever-changing needs of plants to some small degree relative to ever-changing environmental variables. Know what you feed and stick to good irrigation haibits relative to your growing methods.. makes diagnosing problems much simpler. --------------------------------------------- About Lights Hello, folks... This light was sent to me by ViparSpectra. It looks like an excellent light for the price point. They used the most efficient 'white' LED diodes (LM301). They come in both 3000K and 5000K varieties. The average is around 3600K, so it should do you well in both vegetative phase and bloom phase. The 5000k will promot branching early and 3000k will promote bud development late. It also includes diodes for 660nm and 760nm wavelengths (far red and infrared). Meanwell drivers are a well known brand with good efficiency. It has a quality heatsink, too. This is an excellent light that can take you from seed to harvest and produce high quality buds. 8% Coupon Code - XSNobodyBud Note, my screen name is slightly different. Use any code you find for that matter. There are several out there. There are no commissions invovled with this particular code, but I did receive a free light. Nonetheless, I'm an honest guy about this stuff. Amazon US: XS1500 https://amzn.to/3aD5ef2 XS2000 https://amzn.to/3iVUU4J XS4000 https://amzn.to/324iXaV Amazon CA: XS1500 https://amzn.to/31cdHml XS2000 https://amzn.to/3halyGw XS4000 https://amzn.to/32kJzVp Official Website: https://www.viparspectra.com How to use the light based on its specs: Overall, the marketing and advertised specificactions for this light are spot on - without holding me accountable for every minute detail. However, the efficacy is more likely around ~2.5-2.6umol/J ballpark based on specs of bulk of diodes (samsung chips). I'm going to work with ~400umol/s for this fixture. It's a ballpark figure. (375-400 ish). Also based on bulk of diode's manufacture specs... Ballpark figures. PPFD in 2x2 or 4 sq. ft. equals about 1080 PPFD You would want CO2 in this context. 850-950PPFD (~35-40DLI) over 12 hours or about 550-650 over 18hours is roughly your ceiling with ambient CO2. This value can vary by garden. PPFD in 3x3 or 9 sq. ft. equals about 480 PPFD over 12 hours or 720PPFD over 18 hours This is near bottom for a photoperiod in bloom phase given only 12 hours per day, but 720PPFD is still up in a good range for an autoflower in nearly twice the space as above. PPFD x hours of use x a fancy factor provides DLI. So, you can see these things are directly proportional to DLI. Google "DLI Chart" (daily light integral). you can reference time and PPFD for resulting DLI. It is a simple chart of values. Best Practices: Photoperiods- ****Stick to 4-5sq feet for a photoperiod receiving 12 hours of light per day and you will produce as good of buds as you can produce with ambient CO2 levels. A light meter can help determine optimal height. The PAR maps above are a great resource too. 12-16" is probably going to be the sweet spot for this smaller footprint. LUX meters give relative intensity. Compare intensity at edge to middle by percentage. Try to maximize even coverage for your space. Autoflowers- **** You can use this light in a 9 sq ft area, if growing autoflowers, or want kick ass vegetative growth. Math above is based on an 18/6 cycle. It is directly proportional to time as i stated. So, twenty hours of light per day would provide 1/9th more PPFD per day and therefore 1/9th greater DLI too. 720PPFD over 18 hours will produce awesome buds. Over 20 hours, you are right back near ceiling with ambient CO2 - Is 4 hours of darkness enough? Moving on. I'd wager 16-18" will be your height to cover this larger footprint. Again, a light meter and the par map picture provided can help greatly here. Now, all of that is a ballpark to start out. Observe plant and react to its behaviour to fine tune how you use any light. Too much light -- plant may get weak or even fall over. It might get droopy up top, etc. Extreme issues would cause bleached spots that spread quickly in most intense areas of light. Too little light and you will see stretching and pale stems early on or merely too much stretching later. Internode length, too short or too long, will quickly tell you if you need to adjust intensity of light provided. Over the next couple weeks, you'll see me going through this learning curve, too. When you get this light you'll want to torch your plants, but use this information to your advantage. It'll save you time finding that happy zone for coverage and distance from canopy. In the case of a quality light, more is not always better. ------------------------------------------------ FWIW, if you regulate CO2 and elevate it to 'max' levels needed, you can theoretically provide upto ~60-65 DLI over 12 hours. This is a ceiling of ~1500PPFD and ~1000PPFD over 18 hours for an autoflower. Do not try to reach these levels without lab precision in your environment and growing methods. Even then expect to fall moderately short of this theoretical ceiling. I cannot give suggestions here, as i don't regulate CO2. Ambient CO2, figure roughly 35-40 DLI. Regardless, plant dictates these boundaries. This is merely a good starting point -- observe and adjust to reality.