I'm no gardener, and I'm unsure why we have percentages rather than volume or mass, but in the hope I'm not missing some vital point:
You have more chlorex than you need. The easiest thing would be to simply not use all the clorex but use 6/13 ths of it.
If you must use it all then you need to increase the other parts of the mix by *13/6 (or *2.167).
As for the second bit, I'm not 100% clear what you have done but if you have used 100% and should have used 13% then you need to add to the other ingredients (presumably just water) by *100/13 (or *7.692).
Hope that is of use.