Argulus

[checkyohead221]

I made the terrible mistake of not thoroughly checking the new fish I introduced into my tank a few days ago (January 6th) and it is clear to me now that they each have several argulus (fish louse) attached to them. I can see the legs on the argulus move every now and then. They are smaller and whitish/grey. My tank was doing quite well (freshwater, 75 gallons, sufficient filtration and bubbler, good levels of pH, nitrate, nitrite and ammonia, 1 black moor, 2 goldfish, 7 cories) but since I've added two smaller goldfish I am worried they will infect the others. A few questions:

1. I live in the US; what is the best product to kill argulus? This evening I plan to remove them manually, but feel like I need to treat the tank as well in case they laid eggs. I have read orthophosphate is the most effective but I'm having difficulty finding out if products contain it or not. Also, is orthophosphate dangerous for the tank?

Some treatments I'm seeing are:

Tetra Parasite Guard:
http://www.amazon.com/Tetra-77346-Pa...parasite+clear

Crystal Clear Paracid Parasite Treatment:
http://www.amazon.com/Crystal-Clear-...parasite+clear

Instant Ocean Lifeguard:
http://www.petco.com/product/111750/...t=OnSiteSearch

Sentry Mardel Freshwater CopperSafe:
http://www.petco.com/product/5967/Se...t=OnSiteSearch

2. how often/how much water should i be removing? any treatments other than a basic parasite killer I should use?

3. Are these parasite killers effective on all parasites? One of the new fish also has a red streak in its tail fin, and I'm worried it might be a worm or hemorrhagic septicemia.

Please share any experiences you have had. I am very worried about our fish!