ok, there JW, the QT is a 20 gal, and the medication is this stuff called "ParaGuard" by Seachem, I haven't tested the water yet, but I plan on it soon, I haven't went out and gotten a test kit yet, the LFS here says that I don't really need it (I thought they would have sold it to me just to make some money anyway) but that's words from the 4 or 5 stores here, they don't open till 10 am, but I plan on it as soon as they do open. I'm pretty sure that it did spread from other fish.........I had some Damnzels from a store in there b4 and they had passed away (I have never had any luck with that store anyhow, they are just on this side of town) and I waited about a week till I put the new fish in there.........and in waiting for a reply, I read the diseases and treatments page, and found out that the parasites can live 21 days without a host (bummer) I yanked out my filter and there are actual parasites on there (big ones)!!! I also noticed them in my 55 in the substrate, are they supposed to be there? cause the 55 is doing great! the fish are happy, and they look very healthy, might these be the same parasites that are killing my fish? I also did a fresh water dip on the Beauty erlier.......hopefully I will be able to save it......it really is a beautiful fish! also, how can I get rid of the parasites in the substrate of the 55? I have a horseshoe crab in there somewhere that I haven't seen in a couple of days, either it is having a hayday in there or it has also met it's demise. will I ever see it again? if you or someone can help me here! this is weard, algie has never posed a problem, and then this just poped out of nowhere, and it's out of control!!!!!!!!