For our friends in Canada, a DIY copper med:
Into 1 liter of RODI water add:
4 grams Copper(II) sulfate pentahydrate (CuSO4.5H2O)
AND
0.25 gram Citric acid - the acid acts as a stabilizer to the copper in solution.
Never substitute the citric acid with ascorbic acid (Vitamin C) since it will render the copper way more toxic.
Everything should dissolve nicely giving you a slightly bluish solution.
9.8 mL of this solution is necessary to bring 100 Liters (26.4172 US gallons) of tank water to 0.1 mg/L copper. Therapeutic range is ~ 0.15 to 0.25 mg/L, but I would try to stay below 0.20 for sensitive species. Can easily be tested using the
Hanna High Range Copper Colorimeter (HI702).