How much nori do you feed your tangs?

[TCU Reefer]

I'm starting to slowly stock my 215 and I want to get an idea how much nori to feed tangs. I don't want to over pollute the water with too much so what's a good rule of thumb (if there is one) for feeding nori to your tangs?

 

[hdtvguy]

I have 9 tangs in my 300g. I feed a good high quality red nori sheets. I feed 7-8 a day.