I used algaefix for my 10g a week or more ago and I used it once every three days as recommended for a good week and a half and now it's been a week since I used any in the tank, just replaced the carbon filter and I've been doing weekly 25%+30% water changes or more. is it safe to say that there is no more algaefix in my tank? I just bought 12 crs and they should be coming in the mail any day now.. is it safe for me to put them in the tank yet? or should I wait for my next water change or two??