Almost none of nitrifying bacteria lives in the water column. It lives on surfaces--mostly on the substrate & filter media but also on the glass & decor. Doing 90% water changes all day long, won't hurt the cycling process AT ALL. The most important thing right now, is to prevent these fish from being poisoned from their own waste.
What about J-P's idea of adding another established filter on there? That would add a ton of nitrifying bacteria to help out with the bioload.