Some Carbon use/light intensity observations for ya.

[Canadian Man]

Well here's the story.
I change my carbon on a monthly basis. When the month is almost up I do notice a green/yellow tinge to the water. For the past 4 month's I have been keeping track of my findings which are as follows.

-When my carbon is changed my Green star polyps, plate coral and Open Brain(which I have not had the full 4 month's) act difrently for the next few days after changing the carbon. The GSP's open in the morning (when the light's come on) and stay open for about 4 to 5 hours, they then close up for the rest of the "light's on period". when the light's go out they open back up again. The Plate coral react's in a similar maner with it's horizontal polyps closing later in the day. The brain coral takes on a more shrunken appearance but it's been lightening up over the past few month's anyway and expelling it's zooanthella every so often.

- Now I hope I understand the obvious explanation for what's happening. Basically the carbon cleans out the yellow's in the water allowing more light to penetrate the aquarium? Make Sense?

To all you people that don't use carbon, would knowing that if you used it on a regular basis you would get "MORE" out of your light's make you want to use it?

To all the people that do use carbon, do you notice similar finding's in your tank? How do you run the carbon?

The carbon used was/is Seachem carbon in a bag and it's in a spot in my sump that forces water through the carbon but not all the water is forced to pass through the carbon.

Let's here some thoughs.