Sick Fish?

[wild eats]

We have two puffers and a tang in a 180 tank. They all seem to have white spots on their fins. What could it be and how do we take care of them

 

[wild eats]

Yes, they do resemble salt sprinkles. Do you know what this might be, and how to treat it? Also I keep getting brown algae in my tank. My nitrite level is high. I am doing tank change and vaccuming. Would you have any other suggestion on what might be causing this. Thank's!!!

 

[wild eats]

I didn't find anything on hyposalinity. I did a water change, vaccum and treated for ich. The fish look better, the water look's great. Salinity is where it should be. I keep getting brown algae tho. Not sure why. The tank has been going for two months now. I wonder if over feeding could be the culprit? Do you have suggestions on how much to feed? I have two puffers, two damsels, and a hermit crab. I feed krill, brine shrimp,silversides,blood worms. I do these in very small amounts. But am unsure as to the amt. of each, or total amt. of all combined. Also I am getting ready to add some live rock. I have live rock from last time my tank was setup, I will add new rock, to get the old growing again. Any other suggestion's would be helpful.