I'm wondering about interactions between malachite green, formalin, and praziquantel. I've determined that my fish have flukes, and possibly some other internal parasites, and I want to treat my entire aquarium with praziquantel (PraziPro), so I ordered some from Dr. Foster and Smith. The only problem is that it wont be delivered till Monday, which is another three days. The LFS doesn't have PraziPro on hand, which is why I had to order online and now wait for my shipment. In the mean time my fish is getting worse, and my other fish are beginning to show symptoms. My LFS has a solution that contains malachite green and formalin, which I was initially trying to avoid because I have inverts an live rock in my display tank, and assuming all my fish probably have it I wanted to just treat my whole tank with PraziPro. I'm starting to worry that they wont make it long enough to get my Prazi shipment. I'm wondering, if I set up a QT and treat with a low dose of the LFS's malachite green/formalin solution (as apposed to the high dose dip method) for the three days stated on the directions, would it then be safe to add my fish back to the DT after the 3 days (on Monday when the PraziPro shipment comes in) and treat my DT starting Mon with PraziPro. I would do this to kill all traces of Flukes in the tank including eggs, as apposed to leaving my tank fallow, because I don't believe leaving all of my fish in my small QT for a month is reasonable. At no time would the malachite green, formalin, and PraziPro be mixed together with my fish in them, but they would go from the one solution of malachite green and formalin, to the DT with PraziPro. Also, should I add anything else to the DT with Prazi to help minimize the possibility of any secondary infections? Or is all of this a bad idea? Thank you in advance