Feb 22, 2006 · As far as I know, HPS (high pressure sodium) is the most efficient lighting system. With grasses, etiolation doesn't seem to be as much of a problem as it would with e.g. tomatoes.

Dec 20, 2006 · Unlike HPS, you can bring the light practically right on top of the leaves without experiencing leaf burn. Its amazing how if its done right, you can have cuttings rooting in the …

Jan 6, 2007 · A 600W HPS - the proverbial design "sweet spot" - coupled with a digital ballast - less than $250 USD, with a power factor of 0.99 or so - would be far less efficient due to heat …

Dec 28, 2011 · From seeing commercial growers, I usually see greenhouses have metal halides, hps, or T5 flourescent bulb setups so having the right kind of light is very important. For …

Dec 2, 2009 · One option may be to get a 1000watt HPS, or metal halide plant light, which should be enough to keep the plants happy, but cost a lot. Another option is to keep the plants …

Oct 21, 2014 · A 250 watt hps should be adequate for small seedlings in a 80x80cm area, as long as you have lots of reflectors keeping the light in. Once your seedlings get bigger, they will …

Jan 5, 2007 · MH has hazards, HPS is better, but it has a very high operation temperature, as is the MH as well. also your power costs are VERY high. You can get a PFC easily buy buying a …

Sep 4, 2015 · The Excelvan PG01 LED grow light will emit light in the red and blue wavelengths at 620-630nm and 460 to 470nm, these wavelengths correspond to chlorophyll's absorption …

Jan 22, 2007 · The MH/HPS bulbs also can and do explode sometimes during operation sending very hot glass not to mention the vapourized mercuric oxide (s) into the surrounding air. Yes, if …

Dec 20, 2006 · In this class are HPS, or high pressure sodiums, and metal halides. Besides needing a fixture, you will need a reflector, and a ballast to start off. The cheapest of these are …