I just started treatment today on 3 of my aquariums (125 gallon and two 20 gallon) with API Furan-2 and Seachem KanaPlex. All 3 tanks have African Cichlids in them and some of the fish appear to have Columnaris. I normally use the 20 gallon tanks for quarantining new fish and treating sick fish but both of them are stocked pretty heavy right now so like a fool I added several OB Peacock Cichlids I bought a couple weeks ago to all three aquariums including my 125 gallon display tank. I noticed within a couple days after adding the new OB's they were sick. The new fish started getting what looked like a fungus so I started a treatment with API Melafix and Pimafix. It appeared to be working but the fish then started getting open sores on their bodies where the fungus was and stopped eating, so I new I had bigger problems. The Culumnaris has now spread to some of my bigger fish so hopefully the API Furan-2 and Seachem KanaPlex works. I've never had any fish with Columnaris that I know of in all the years I've had aquariums so this is my first time using API Furan-2 and Seachem KanaPlex together as a treatment.