purple tang

The lack of spots doesn't necessarily mean they are getting better. It might though.
Ich has a life cycle where some of visible parasites will drop off and fall onto the substrate to reproduce and reinfest any fish they can. That gives no indication of how many are still left infesting the fish. The visible white spot is actually not even the parasite itself AFAIK but is the indication of where it is deeper under the skin. It's just a symptom.
I would suggest doing some searches on it, there's a lot of information out there.
Here are is one article about it.
Marine Ich/Cryptocaryon irritans - A Discussion of this Parasite and the Treatment Options Available, Part I by Steven Pro - Reefkeeping.com

Be careful though, there are a lot of opinions out there about it.

 

Screwtape i just read that article. It is very thorough and gave me good information. I was thinking about the hyposalinity treatment. Now I always thought a quaratine tank was a waste and infections were rare but Im going to buy one now. Obviously i wouldnt buy a giant QT but this article says to keep the fish in the QT for a pretty long time, would this be bad putting 2 tangs in there? Now the article also says that the trophont is most likely to leave the host during the night. So i figure tommarow i buy a QT and get water in there. Make sure everything is spot on including the 1.010 salinity. Then the next night, when the lights go off wait 2 hours, take the two tangs out and get em in the QT. Then daily, do a 50% water change untill the fish look and act clear of ich(not that their acting funny right now). Then increase the salinity by .002 each day till its 1.025 then bring em back in the DT. By then all the parasites in the DT should be gone right? Thanks for showing me the article! and everyone else whos giving me info.

ps: Im not sure if the water change is even neccasery daily because the salinity should kill the parasite on its own; let me know what you all think

 

I'm no expert on this, I've never had to do it so I'm just encouraging research and sharing what little I remember of some of the articles I've read in the past.
Here's one article on it in case you haven't seen it yet, not that I'm necessarily encouraging this method of treatment, just because you mentioned it.
hypoOSTtherapyart.htm

AFAIK in order for treatment to work you need to have all your fish in treatment pretty much otherwise the ich still has a potential host to continue it's lifecycle. Are those the only fish in the tank? Otherwise they could just be reinfected as soon as they are returned to the tank. I believe a fishless period of 6 weeks was recommended last I looked into it, to be sure. Some people have gotten away with less of course.

If you decide on hyposalinity you can't just treat them until they look and act clear you will want to do the whole period, I believe minimum 3 weeks. A little longer to be more certain I think. If you do it shorter there could still be parasites in the tank. Keep in mind that these parasites are living things and aren't necessarily going to drop off the fish at the stroke of midnight or aren't going to necessarily be completely eradicated on the 21st day of treatment. There is always variability in these things.
Also I would make sure you're 100% trusting in your salinity measurement method, refractometer would be preferred, with calibration fluid.

 

Nope in the tank i have the 2 tangs, a clown, a fairy wrasse, sixline, and two damsels. How big would you say the tank would have to be for this? Cause i dont want to stress this fish more. My cousin said increasing the temperature works also but im a little reluctant to do that in the display tank with everything else. And yes im gunna need to get a refractometer

 

That's tough with that many fish. I would consider at least a 55g, bigger if you can. Maybe make sure you have some in-tank acclimation containers or some type of dividers available in case there is aggression or something. Is there maybe a reef club in your area that you could ask for help or borrow a tank?

Increasing the temperature a little bit can apparently speed up the life cycle of the parasite from what I've read, depending on what you are keeping your tank at now it might not be a bad idea, even a degree or two will speed it up a little bit and every little bit might help. Bumping it to 81 or so shouldn't harm most things although I won't say everything, it depends what other stuff you have in the tank and how healthy and settled in everything is.

 

I would just let them go for now. Transfering them to a smaller tank will just stress them out more. The quarantine tank is a good idea, but for you specific situation, I don't think it will help. I would wait a little longer to see if there is any improvement. Just keep the water as clean as possible, wet skim if you have to, and make they are eating. As long as they are eating, they should be able to fight off the parasite.

 

+1. I agree with waiting a bit longer to see if they can fight it off. I have tried removing fish before when they are sick and it really does stress them even more. Let alone the stress of being in an unfamiliar environment (the hospital tank) or the treatment. I have a purple also that went through this when I first got him. It took about 2 weeks for the white spots to clear up, but during that time, I kept him well fed with a variety of food but especially the nori soaked in garlic and vitamin C.

 

Yeah I'm gunna keep them how they are since everyones eating and acting fine. Tonight I'm gunna bump the temp up to 81 tonight from 79 and see how that is

 

This is a little off topic but why make another thread for just one thing. Im not sure when i first noticed this maybe a week or 2 weeks ago, but theres little shells, rock rubble, and hemit shells all of the sand bed. My hermits all have black shells and im finding white and purple shells everywhere. I havent arranged my rocks in a while and theres little pieces it looks like of rock on the sand. and finally theres these baby clam looking shells and i dont know where there comming from. i usually take them out but with the tang having ich im trying not to put my hand in there as much. and now im getting brown algea on the sand so its gotta be from these things!

 

Brown "algae" on the sand is usually diatoms which are natural. If you control your nutrients properly they may bloom up from time to time but should disappear within a few days or a week.
Those shells are either falling off of or out of your rock or possibly came mixed in with the sand and are just making their way to the surface because they're less dense than sand. All natural processes in a tank. I just leave that junk in there. I think it makes it look a little more natural but if you don't like them in there it doesn't hurt to take them out, I doubt it's the source of your issue though.