Planted Tank Guru
Join Date: Sep 2006
Location: Northern California
Start another tank, don't plant it, low light levels, completely cycle it with any new Eco-Complete if you want. Cycle with any filters you can spare, HOB, canister, heck, even sponge filters. Let's call this Tank2.
Warning: I'm not sure of the size of BBA spores but I'm guessing your filter media will be laden with the spores. I wouldn't re-use it...just in case. Again, I'm only speculating, which is dangerous, but it's the best I can do without more research on BBA.
When it's time to move, move the fish to Tank2. Nuke the old tank (Tank1), run all the equipment from Tank1 on Tank2 so that the filter pads can be re-established, then move fish, equipment, substrate back to Tank1.
I don't see of a way to nuke the tank to rid yourself of the BBA spores AND keep around any beneficial bacteria. The method I proposed is probably one of the safer ones, but also the most time consuming, requiring you to have a spare tank and a spare filter or two handy.
Any treatment of the mulm and/or filter media with H2O2 and/or Excel will probably kill off at least a good portion the beneficial bacteria. H2O2 is a strong oxidizing agent, and the active component of Excel, glutaraldehyde, in higher concentrations, is used as a sterilizing agent.