Ballasts

[Ian Cameron]

I am a great believer in the old saying - "He who asks a question is a fool for 5 minutes, he who does not, remains a fool forever".

So, here we go, I recently had given to me 8 HPS ballasts, 16- 1000w lamps, 20 umbrella shaped reflectors, plus various other goodies. Came from a now defunct medicinal operation.

Question 1: Is it possible to run 250w or 400w lamps on these ballasts? They are coils with capacitors and  igniters separate. I have checked out all the units and they light up with no problem.

              2: The reflectors are 48" in diameter. My grow beds are 26" *48". Would the reflectors work on them with reduced wattage lamps? If not what would you folks recommend?.

             3: Should I be using vertical or horizontal lamps? I plan on starting with fresh ones.

I have been running T5's for 2yrs, 200w per grow bed and need to replace them. Heat is not a problem, up here in central BC and on wood heat I can use every BTU I can get.

Thanks for any help

Ian

[Glenn]

1~ Yes. Using lower wattage lamps with higher wattage ballasts is quite ok, but not the other way. It is a typical strategy to use lower wattage lamps while plants are small and less densely leafed. Then to use the higher wattage lamp raised higher to cover wider and denser foliage. There will NOT be as much of an energy savings as if you used a 250 watt lamp with a 250 watt ballast. There is simply more losses in a higher rated ballast whether used or not. and I think running 250 watt lamps on a 1000 watt ballast will actually burn about 325 total watts. While a 400 watt lamp will draw around 460. 

2~ The shape of reflectors does effect how the light is directed. Shaping it to more directly light the largest volume of young growth is what I think we should aim for (pardon the pun) but that might be more opinion than anything else..

3~ I do know that I have had better results with vertical lamps. AND I advise to keep from creating bright spots on the lamps themselves. Keeping reflectors from beaming light and heat right back at the lamp is one concern, but the larger concern is defects on the lamp surface. Dust, debris, vapor, and even small amounts of oil from fingerprints are neglected thieves of our highly prized lamp's lifespan.

I hope this helps.

[Ian Cameron]

Well, thanks for the advice Glenn. I think I will try a 250w and a 400w lamp, plug my watt meter in to see what is actually being drawn from the ballast. I kinda thought about the unused power overhead and did not quite understand how to calculate it out. It should be interesting to find out the real draw of a 250w - 400w Vs. the rated output of the ballast.