NaH2O, it appears you are not comprehending the posts, are you saying that if you have a disease or other "bad" condition in your tank you would not add anything that would compromise your good bacteria? how then would you correct the above problems? anyway, it was not suggested by anyone that an anti-bacterial agent be used.please go on the web and check out "pro-biotics" then perhaps you will be better equiped to comment. and there is a difference between the words dissolving and erroding, of cource erroding is natural and expected, but dissolving that can be "seen" would not be natural. sugar dissolves in water, but it's structure errodes when damp. your last post reads "not really dissolving", that is not what you said the first time, had you said erroding I would not have stated "serious" condition, perhaps when a person offers help we should monitor our proposed help so as not to cloud the issue thereby really helping the thread starter. heavy coralline growth depleats the water of minerals ie: ca, mg, etc if the minerals are not replaced the coralline stops growing and dies, and its dissolving structure puts minerals back into the water to be used by lifeforms. the bacterias sold as cycling aids are selective bacteria their presence in the tank degrade "bad" bacteria to the point that they become non threatning.