Hypo is easy if u can hold salinity right at 1.009. Ato will help. U can have a lot of water made at same salinity and do frequent water changes during treatment while copper will cause more issues with beneficial bacteria and it also registers as ammonia on test kits so its harder in non cycled qt.
In hypo if u show ammonia u do water change ur done till next round but with copper first u wont know if ammonia on results is true or false reading then after water changes u need a copper test kit to hold it steady at 0.5 so will have to redose according making it a bit more difficult for new hobbyists.
In hypo if u show ammonia u do water change ur done till next round but with copper first u wont know if ammonia on results is true or false reading then after water changes u need a copper test kit to hold it steady at 0.5 so will have to redose according making it a bit more difficult for new hobbyists.