Very useful calculator, thanks 
By the way I am dosing Iron Sulphate, I wonder if there is an existing entry I can use? If not is it posssible to add to the calculator? - https://www.bunnings.com.au/manutec...MnGmcDRpgJtKjo_HZ7gaAsA5EALw_wcB&gclsrc=aw.ds
By the way I am dosing Iron Sulphate, I wonder if there is an existing entry I can use? If not is it posssible to add to the calculator? - https://www.bunnings.com.au/manutec...MnGmcDRpgJtKjo_HZ7gaAsA5EALw_wcB&gclsrc=aw.ds