Thanks SPS911, ups did not remember were it was and couldn´t find it.
Ed,
I have a doubt, earlier in this thread you mentioned:
"but most acros color up best under my lights in that 350-450 range. Some of it's species specific.............Millis like more intensity especially reds/ pinks. Most smooth skinned acros will color better at 250-350 range."
I thought that 6 hours of of full light was more than enough for acros, but I read that you give acros a full 8 hours of light. I understand that it would be 8 hours of 350 par . What would be the effect of only giving 6 hours or 8 is better?
I thought you could give more than 6 hours of light but you had to decrease the par.
would acros color up better with 8 full hours at high par ( high beging the range you gave above 350-450)??
What would be the effect of supplying more than 450 par? less color?
Sorry for asking to much
Hopefully this will cover the questions...........first off---
A combination of intensity, spectrum and nutrient levels all play a role. Flow is also important, but most people don't struggle with that.
You can do less than 6 and probably be fine. I do eight hours full on because it works for me as far as enjoyment of viewing the tank for a certain amount of time and what still works for growth and color.
I'm not a fan of the dominant blue dawn/dusk look, so I don't use it. When I've run any type of dawn/dusk, I just would not turn all the lights on at once. It's really more for the fish, they prefer to acclimate slower to the light, but if you have ambient lighting from windows or whatever, that serves the same purpose"¦"¦"¦"¦.corals don't need dusk/dawn in our tanks.
Another reason for 8 hours is again for the fish"¦"¦..I don't think they'd do as well long term only getting a short duration of light. In the end you do what you like, works for your schedule and still accommodates the animals in your system.
On natural coral reefs in less than a half hour the sun is hitting the corals at full intensity and at much higher levels"¦"¦"¦..the important thing to remember is the earth is moving, so each section of a coral gets a lot less (time duration) of that intensity"¦"¦"¦"¦ it's a reason they grow in such nice perfect shapes. It's very similar to how a tree looks that is in an area open enough to get all angles of the sun.
Our tank lights are static so you don't need anywhere near that same amount of par.
Also remember, what I'm relating is my experience with T5 and par levels. They can be used as a guideline for other light forms but aren't exact rules.
It's really more important to look at the corals and how they are visually affected. You don't need a par meter and are probably better off without one, but since LEDs have been out everyone thinks they need to know exact par numbers.
A par meter is good for defining a top and bottom area to place the corals. I gave you that range"¦"¦between 500 and 200. The rest is a matter of looking at the corals and how they respond, color and grow when placed in that range.
For example, the smooth skinned acros will bleach or pale if I set too them too high in my tank and a milli at the bottom of the tank will brown out.
Sorry for being so long winded above"¦"¦.in short, for acropora the point is to use a lighting system that creates consistent spectrum across the whole length and width of the tank. You then just need to set the coral at a level in the tank where it does best"¦"¦"¦"¦the par levels I gave you can suggest a good starting point.
If you get those variables nailed down it's much easier to work out a duration that fits your livestock and personal enjoyment.