How much each feeding?

I always seem to guess at how much I should be putting in there for my guys.
Right now I only have a medium size yellow tang and two percula clownfish. One small one medium. Also, a peppermint shrimp
I am giving them about 2 pinches (maybe 20 tiny pellets)of hikari marine -s- pellets and a pinch of o.s.i spirulina flake. Twice a day.
Is this enough for them?

 

If they are getting larger yes. If they seem to be getting skinny you will need to add more.

 

Only had them a week.
How about what I am feeding? Its good stuff but is it enough nutrients?

 

A good rule of thumb is to feed just enough that will be consumed by your fish within 3 minutes, with as little as possible hitting the bottom. As far as how often, two or times a day (small feedings) should be fine. Also, check your nitrate level every two or three days until you feel comfortable with the amount and frequency of your feedings. If nitrates are getting too high, your probably feeding too much.

 

the more nutrients you can export the more you can feed...
this comes in handy when you strive for an ultra low nutrient system (ULNS). if interested in one, try googling it for details on how to achieve