Yea, the tangs are smart little dudes. Most sps only extend their polyps at night as I stated earlier, but the tangs chew the tips down enough that there are NO polyps left. As for macro algea in my tank, NO WAY. That stuff is very invasive and can overcome a tank rather quickly. Also, if you trim the algea allot (which I have had to do) it releases a toxin into the water that the SPS do not like. I have about 30 pounds of Macro in my turf sump and I take this hugh mat out to trim it and let it sit in another unit for a couple days so the macro can heal and not release these toxins. I usually cut it in half and throw it away. To bad I can't put it in my compost heap. As for feeding, I feed 2 or 3 times a day. These guys are fat but I think the sps must be like chocolate to them. Another thing about having macro algae in the tank is they grow over openings in the rock work which slows the water flow down and that becomes an issue. Although it sure looks nice. I do put small rocks into the main tank that have macro on it so the tangs can eat it. They usually clean it up in a week or so and then I change out that rock with another one with macro on it. Works pretty good. I am thinking about getting a piece of plexiglass and standing it in a corner and trapping these tangs in there. I have figured out a way to pull the plexiglass closed after they get in it. Kinda funny to sit and watch TV with a piece of fishing line in your hand waiting for the fish to go into it. Of course, they hide unless there is food floating around and then their hunger overtakes their caution. Next time I have a problem with hair algae, I am just going to buy a bunch of hermits to fix this problem. I usually start getting hair when my RO needs to be changed out. And by the time the hair starts, it is to late to really stop the problem. Sure, I change out the RO immediately, but by the time you realize you have an algae bloom, it has not reached its peak yet. And before anyone tells me to buy something that absorbs the phosphates, those things never truly work. Just a bunch of money wasted. I think I will try the net/food idea first. I think this time I will use white fishnet. They won't go near green or black anymore. Haha