Should I remove my drift wood?

[Drayven]

Ok ever since I started up the tank I've had issues with mystery deaths, mostly weather loaches but a couple danios and a sword tail too. Water conditions are just fine with 0 nitrite/ammonia and nitrate is usually around 8 or less. I had a danio that got sick a couple weeks back and had a white band around it, took a pic to the LFS and they gave me some fungal eliminator made by Jungle I think it was. I followed the directions and treated and waited 4 days, did a 50% water change then treated with the rest of the bottle. The second dose wasn't a full dose because the bottle only does 75 gallons and I have a 50 gallon tank but I figured a 50% dose was better than nothing. Now that has a couple days left on it but this morning my swordtail has a white fungus looking thing on his side and the tip of his sword is a little withered too. Went back to the fish store and picked up API fungal medicine to try out. Which means I treated the tank a while back with Pima/Melafix, then the Jungle product and now I'm doing a big water change and will treat with API.

What I'm wondering is this. I have a big chunk of driftwood in my tank. Is it possible that the medicine isn't penatrating the wood deep enough and the fungus is living inside it? The reason I ask is that to remove the wood would be a major project because it's the biggest piece in the tank and it is completely covered in java moss which has a fairly large colony of cherry shrimp living in it. If people feel there's a real chance that removing that wood could help with my problems I'll get rid of it but if it's not likely I'd rather not mess with it.

I'm just kind of at my wits end here. I take great care of my tank and my fish get sick and die, I have friends that barely remember they have a tank and their fish thrive, argh!