2 weeks ago, I introduced a German Blue Ram to my tank. He exhibited rapid breathing and stringy white feces almost immediately and died the next day. Suspecting internal parasites, I dosed my tank with Prazi Pro. All fish looked fine for about 5 days. Then my Harlequin Rasbora started showing signs of what I believe is Columnaris ("white" fins sticking out, go filmy white after death). 2 rasbora have died so far... and now my favorite fish, a Powder Blue Dwarf Gourami is looking like he's on his way out. He shows no outward signs of Collumnaris, but is exhibiting strange behavior. I've added aquarium salt to my tank, cut the lights and heater off. I know that I shouldn't put another med in with the Prazi Pro. Today is day 7 for the 1st dose of Prazi Pro so I am ready to do a big water change. Should I... A. Do a huge water change to get most of the Prazi Pro out of my tank and dose with Fuval 2 or Kanaplex (whatever I can get for Gram - bacteria). B. Do a huge water change, put aquarium salt back in the tank and give my fish the recommended 3 days rest from meds (after being dosed with Prazi Pro for 7 days). C. Something else??? ... suggestions are so welcome.