I think the main reason they recommend the higher dose when adding it directly into the tank is to reduce the amount of time it takes prime the completely mix with the water and deactivate the chlorine. The water conditioner won't instantly make the water safe. it needs some time to mix and react with the chlorine. Its probably not much time but it definitely is not zero seconds. And if your water has a lot of chlorine your fish might not like water changes.
I personally use RO water, no chlorine, lead, or uranium. I don't need a conditioner and I haven't purchase any for years.
I personally use RO water, no chlorine, lead, or uranium. I don't need a conditioner and I haven't purchase any for years.
