Just for general running it works out to 1.578 grams per liter for me. A bit more or less is not a big deal. If I was going to run 2.5-5g it would only be as a treatment for something specific and I would not do it long term. At the 5g end I would watch things very closely, might be a bit too much. Hope that helps some.
Since in the US we cannot manage to adapt to the metric system I measured one rounded tablespoon on my scale. I called it 30g I rounded 5 gallons of water to 19 liters. The directions on API aquarium salt calls for one rounded tablespoon per five gallons of water for regular running. It also explained that salt will not evaporate so only add when changing water. I think that is obvious but it must not be.
Since in the US we cannot manage to adapt to the metric system I measured one rounded tablespoon on my scale. I called it 30g I rounded 5 gallons of water to 19 liters. The directions on API aquarium salt calls for one rounded tablespoon per five gallons of water for regular running. It also explained that salt will not evaporate so only add when changing water. I think that is obvious but it must not be.