Hello.....My fish started to scratch on the sand substrate in my aquarium. I now noticed white spots on my P Bass & TSN. I raised the temp to 86 degrees and added 33oz of aquarium salt. The carton states treats up to 220 gl of water. My tank is 300 gl and was wondering if this amount is enought taking the substrate and driftwood, etc into account? Any advise would be greatly appriciated.