I firmly believe in doing the bucket transfer method to really cure whitespot. Been doing that for years and got a 100% survival rate. However, I got asked a question around copper and I cannot find the answer. As we know, copper is only effective during the free swimming stage. Basically it poison the whitespot theront more than it poisons your fish. How long during this short period, can the theront swim around in the copper poison, before the copper will kill it? Is it like a headshot - boom - wasted action? Or does it take 5 minute? half an hour? hour?