Quote:
Originally Posted by andsoitgoes
I think I saw that page a while ago, it makes my head hurt 
Hm, so supplementing with 10k PC bulbs would be necessary. Now, my question is can a bulb be found (14k) that has a minimal or nonexistent drop in PAR?
Especially seeing as that page has tests from almost 10 years ago, the technology has to have improved somewhat, right? |
Sanjay's page is very easy to use:
1. Go to "Search Performance Data"
2. Go to "By Ballast" (in your case)
3. Select "Watts = 150", "Ballast type = HQI" (for your DE bulbs), "Shielded = Both" (your unit is most likely shielded, but you get a better idea seeing both options)
4. Submit
5. The chart that pops up default ranks from highest PPFD (aka "PAR") to lowest. For example, the G-man 10K shielded bulb has a PAR of 72. Not bad for a shielded bulb. The highest PAR comes from the unshielded Icecap 6500K.
As you can see, PAR values tend to degrade as K-values go up.
Another interesting bit of info Sanjay gives you is the "CCT" column. This is the ACTUAL measured colour temp of the bulb. For example, the shielded G-man 10K bulb's actual colour is slightly warmer at 8,552K whereas the Aqualine Blushke 10K bulb comes in cooler at 12,229K.
Sanjay's data is by no means "out of date". He constantly adds to the data as he tests more bulbs and ballasts. He uses the same bulbs and the same ballasts that we use. The 10K G-man bulb he tested is the same 10K G-man bulb on J&L's shelf and the M81 HQI ballast is the same design of ballast sitting under your tank. This page is one of the too few UNBIASED + scientifically valid sources of information in this hobby.