[StirCrazy]

Originally Posted by Canadian

I know you like to say this but what is it based on? Your measurements of a Tek fixture in Safari way back when? For reference, I measured the PAR of my 6x24W ATI Sunpower fixture with 8 month old lamps in a 24x24x20 tank and found the following measurements:

At the surface: ~ 600-700 μmol m-2 s-1
Mid tank: ~ 400 μmol m-2 s-1
Bottom of the tank: ~ 200 μmol m-2 s-1

.

your own measurments confirm it.. I had 600 with the cheep bulbs and 720 with my ABs at the bottom of a 24" deep tank plus 6" air so for a distance of 30" so at the bottom my MH were putting out over 3X what your lights are.

you don't need to get defencive of the T5's though as they do have a place, they replaced PC, VHO ect and do a exalent job of it and offer more color combanations which is great. but for the pure punch power you can't beat MH.

another problem that comes to light is the numbers the T5 people like to use to compare are old sanjay tests and such were the MH were tested with out reflectors. test your T5 with out reflectors and tell me what happens. the same thing happened when 150watt DE first came out on the market, which led to claimes of being better than 400 watt SE set ups. the 150 bulbs were being tested with optimum reflextors against numbers that werre derived from black box testing.

to show how much reflectors can skew things, there is now way I should have had a higher PAR level with my 250 watt SE AB's than 400 watt SE's but I never found a 400 that could beat mine. but that is cuze I used computer generated reflector patterens designed for office lighting and made my own reflectors out of 98% silvernickel plated material which is the highest you could get at that time. the 400 Iwasaki was on a home made pollished aluminum reflector.

I have so standoffs and a good T5 ballast so I will get some bulbs and if I get my MH this week I will do some "no reflector testing" just have to figure out how to eliminate the reflector in a 150 watt DE. I can do it in my garage so I can set up exact distances from the center of the bulb. heck I can even go longer distances if I want to see the drop off values. won't be till after christmas though.. going to be busy with a new puppy next weekend for a while.

how are you liking your new meter and which one did you end up getting?

Steve