Gilles;57197 said:Problem with that is the method of measuring. Full tank / how full / how cloudy is the water or is it crystal clear? etc...
hbosman;57198 said:Indeed true. If they were all measured under the same conditions though, at least you'd have comparison.
I used this chart two years ago to buy geissemans and GE Starcoats. Recently, I learned that 4 bulbs over my tank was too much. Since my Geissemans and GEs are old, I dug out two Current bulbs that appear to be low PAR (on the chart) and my plants are still doing just fine and I fight algae less. My tank is 22 inches high.
Now I'm more inclined to buy T5 HO bulbs that are locally available and look good to me. The shipping charges for bulbs kills the price advantage of buying off of the net. Unless, you want a specific bulb of course.