There's a lot that goes in to what PAR a specific type of coral seems to like. There's also a lot that goes in to exactly what PAR is but for the sake of my comments and reflections, let's just go with PAR being the amount or intensity of light that our tank inhabitants are receiving. ARC owns 2 PAR meters and I have had the privilege of taking quit a few measurements in fellow member's setups. One thing that I keep thinking is that PAR doesn't matter nearly as much as I used to think it did. Obviously there has to be some pretty intense light to grow corals but for a long time I focused on PAR as the main reason I was limited in what I could grow.
Over and over again I've taken reading that I would have otherwise though impossible. For example, one member had a clam at the very bottom of his tank and the reading was 80-90 PAR. I assumed it was a fairly new addition and felt bad because I assumed it wouldn't make it very long under such a weak light. When I asked how long he'd had it, it had been in the system for 2+ years. In another case, I saw a Walt Disney frag with full polyp extension and good growth under 600 PAR! In the past I would have assumed the coral would bleach in short order with that kind of light intensity. Finally, I was at yet another member's place and the highest PAR anywhere in the tank was around 100 with most of the tank getting quite a bit less. What did I see in that frag tank that 'didn't have enough light'? SPS, Zoas, LPS, and softies galore all looking full, happy and fully colored. So, what gives? Was I mistaken yet again in my belief that PAR was one of the most important elements in reefkeeping? I'm finding out the hard way that nutrients play a significant role but I would have never guess they were equal in importance to PAR.
Side note: ARC does have 2 PAR meter and I'd be more than happy to come and take a reading or work out a rental if anyone's interested. Another member has the other meter and takes care of the North/Northwest side of town but I'm available to cover anyone from Duluth down to South of the city. I live in Stone Mtn and if you'd like to arrange a PAR reading, hit me up over DM and we'll talk schedule.
Over and over again I've taken reading that I would have otherwise though impossible. For example, one member had a clam at the very bottom of his tank and the reading was 80-90 PAR. I assumed it was a fairly new addition and felt bad because I assumed it wouldn't make it very long under such a weak light. When I asked how long he'd had it, it had been in the system for 2+ years. In another case, I saw a Walt Disney frag with full polyp extension and good growth under 600 PAR! In the past I would have assumed the coral would bleach in short order with that kind of light intensity. Finally, I was at yet another member's place and the highest PAR anywhere in the tank was around 100 with most of the tank getting quite a bit less. What did I see in that frag tank that 'didn't have enough light'? SPS, Zoas, LPS, and softies galore all looking full, happy and fully colored. So, what gives? Was I mistaken yet again in my belief that PAR was one of the most important elements in reefkeeping? I'm finding out the hard way that nutrients play a significant role but I would have never guess they were equal in importance to PAR.
Side note: ARC does have 2 PAR meter and I'd be more than happy to come and take a reading or work out a rental if anyone's interested. Another member has the other meter and takes care of the North/Northwest side of town but I'm available to cover anyone from Duluth down to South of the city. I live in Stone Mtn and if you'd like to arrange a PAR reading, hit me up over DM and we'll talk schedule.
My plan will be to switch lights and measure the before and after. I’m in the Dunwoody area.
