I'm not on my regular computer, so I can't see your photo right now.... However.... Ich looks like grains of sugar or salt.
If this is what he has, the simplest treatment is simply to raise the water temperature to at least 86F (30C) IF the other fish in the tank can withstand that high a temperature.
Ich is a parasite. Elevating the water temperature prevents them from reproducing, so eventually, the parasite dies out.
Keep the water temperature high for at least several days after you see the last of the white spots. If raising the temp to 86F (30C) doesn't help, try increasing it to 87-88F (31C), as sometimes the parasite is resistant and higher temps are needed.
That's it. If it's Ich, then just elevated temperature is all that's needed. There's no reason to use medications, IMO. Keep the heat raised until at least 5-6 days after you see the last of the white spots, in order to make sure they've all died off.
-- If you want more detailed info on Ich, read on:
The white spots that you're seeing are from parasites that have burrowed into the fish. While they're burrowed into the fish, they're protected from harm. They'll eventually fall off, but it takes a few days. So it can take about 5-6 days to see results using the heat method.
There are 3 parts to the life cycle of Ich: Stage 1) trophont
- this is the stage where you see the white spots. The parasite has burrowed into the fish, where it's protected from treatment (which includes medications, salt and heat). So treatment isn't effective here. This stage lasts several days. Stage 2) tomont
- the trophont finishes feeding, and falls off. It's now called a tomont. Since it's in the water column, treatments (medications/salt/heat) are effective now - BUT only for several hours. It then forms a protective cyst around itself, so treatment isn't effective. Unfortunately, the organism is reproducing during this time. Stage 3) thermonts
- Several days later, the cyst bursts, and lots of new organisms go in search of a host fish. They have several days to find a new host, or they will die. Treatment is effective during this time.
So basically, you have to treat while the parasite is either in the early part of stage 2, or during stage 3....
Some people also use aquarium salt or medications (especially ones that contain both malachite/Victoria green and formalin) in addition to heat. But obviously, heat alone is less toxic than adding salt/medication, so it may be something you want to try first - but it does take time to treat this way.
Because the parasites go through three stages, you'll also need to continue treating for at several days after you see the last of the white spots go away. This is because the parasite is only visible during stage one. There are other parasites in the tank going through stages two and three, (but you can't see them,) so you need to continue treatment until it's gone through the entire life cycle sequence.