Quote Originally Posted by Feline View Post
Best idea is to just get a REDOX/ORP meter and then you can dose accurately without the risks of ‘does it look pink enough’. You slowly add the PP, mixing it in thoroughly, enough to keep the ORP reading to 450mV and no more for the 4 hours of the treatment. As the redox reading falls you just keep topping up to keep it there.

How much PP it takes to achieve that reading is really not that relevant- as said above depends on organic load of the system and ‘stuff’ already in the water such as fish pheromones, dissolved proteins, ST and previous chemical treatments.

PP just oxidises stuff until it runs out of stuff (other than your fish) to oxidise.
Thanks Feline, Someone else on another site suggested getting an ORP meter, so looks like I will have to invest in one, It would make life easier.