are there different types of this virkon as there seems to be different wording so im assuming its possibly strength of it ??? iv tended to not use PP plus iv never used C/T as im in very soft water Area and although the pk gives its dose reductions as i dnt know enough about it ill give it a wide birth for now so im thinking a mild dose of virkon will assist in cleaning up in the pipework filters ect of ANY UNWANTED NASTIES or am i barking up the Wrong tree