Nate you want to take several different very broad topics and combine then into one little package and thats not going to happen here on MR.
A few topics your talking about are how to achieve a low nutrient system in a close environment, how low nutrient systems affect corals, how light affects corals, how corals use that light, coral colors, the list goes on.
Don't want to get too off topic here, but MR is full of little bits and pieces of info which you piece together to get a bigger picture of what should/should not go into an aquarium. The issue on this thread should be light and how light intensity (low or high) plays 1 of the many parts to a successful aquarium. For a successful aquarium, every aspect has to be correct. 1 of these aspects is lighting which is what was intended by this thread. I agree that other factors influence this lighting issue as well, 1 of which was pointed out by both you and Deanos in Article 3 of the lighting vs flow series. That article gives a lot of good info on how much lighting should be hitting corals given a specific flow rate.
I said this last month and I believe others agree. Don't obsess about your ppfd levels, just make sure you have a good lighting setup with regularly changed bulbs. And like Rich said...
You and others have been saying "don't worry about PPFD", but why? When I went from my old 400W setup, to my new 400W setup, my PPFD doubled. Again, not saying that it has helped yet, but just saying that it has doubled. If there is any empirical evidence or articles showing why PPFD doesn't matter that much, then pls point them out to me. But so far people have just said "it doesn't matter that much" without any backing.
I couldn't agree more with what Rich said. Which is why I got rid of my old lighting system and went with one that was proven successful. If I still end up having problems, I'll know that I'm barking up the wrong tree. Still too early to determine if it has helped or not. I have seen improvements, but don't want to jump the gun on it.
You might want to look elsewhere in the tank, when I said filtration earlier, I didn't mean test your tank with a hanna meter. Filtration is a broad subject, so I have a few questions for you.
Are you still using the same dsb and rocks you had in your system before you joined MR when I delivered my chiller to you?
My old sump is gone along with the rock and chaeto in there. I now have a clean and empty sump with filter
socks, 2 phosban reactors with phosar and carbon. I've had the new sump a little over 2 months now
Now I DO still have the same live rocks and sand (my display tank sandbed is not DSB, just the Fuge was) in my display tank that I've had since I started my system. Don't want to put words in your mouth, but are you saying that this could a prob? Hadn't thought about that at all.
Not sure if you remember but when I was by you that time I told you to dump the stuff in your fuge area and when you finally did it this year your inorganic phosphate dropped from .08 to .03.
Yes. That totally helped. I don't remember you suggesting it but I'm sure you did. Should have done that a LONG LONG time ago.
Paul, after re-reading my post, this may come off as combative. Hopefully you don't take it that way. Just want to challenge a couple things and see what you and others have to say. I respect your opinion highly. This hobby is filled with a lot of assumptions and "I thinks" which have shaky backing. I know we have a LONG way to go and I'm sure everyone has beliefs about reefkeeping that are incorrect and need some challenging (myself included).
Thanks,
Nate