<a href=showthread.php?s=&postid=6622099#post6622099 target=_blank>Originally posted</a> by Angel*Fish
I think part of the reason for this is that your question is somewhat vague. Maybe if you post which types of tangs/angels you want to keep,we'll be able to give you a higher quality answer.
Depending on the type. adult angels range in size from about 2.5 in to about 1.5 feet. Mature tangs may reach from ~7 inches to over 2 feet, again depending on the species.
Bioloadwise - the 3 inch angel is practically nothing in a 300g. But even though a 12 in angel is only 4 times longer than a 3 in., it is many many times bigger & would affect the bioload much much more than say 4 of those 3in. fish. A 12 inch angel might be 20-30 times the bioload of a 3 inch angel.