after a bit of googling, i found a caution regarding the use of this product: "contains a dilute oxidizing agent. do not mix with vinegar or other acetic cleansers"
then i found this at wikepedia regarding vinegar and acetic acids: "Due to incompatibilities, it is recommended to keep acetic acid away from chromic acid, ethylene glycol, nitric acid, perchloric acid, permanganates, peroxides and hydroxyls." both permanganate and peroxide are common oxidizing agents.
from the short search and results i did on this product, i would keep it out of aquarium reach. it has the potential to muck with PH, kill plants, inverts, and scaleless fish, and rob your water of oxygen. HTH.