A salt rate of .03% will not affect your nitrifying bacteria enough to cause any major problems (assuming you're not grossly overstocking/over feeding you tank). We have at times had it up to .06% with no noticable affects on freshwater fish. If you are really concerned about it, add the salt slowly...over the course of hours or days to let the bacteria acclimate to the change in salinity. Of course at that point in time, bacterial control wont be the primary goal (minor/simple parasite control would be, along with stress control).
To determine how much salt to add into a given body of water here is a helpful formula:
gallons of water/125 x desired salinity (in ppt) = pounds of salt
Example:
100/125 x 3ppt = 2.4 pounds of sodium chloride to bring 100 gallons of water to a desired salinity of 3ppt (.03%). This is also assuming the water does not have a salinity to begin with. If it does, the formula is easily adjusted for this. Say it has 1ppt salinity and you want 3ppt. 3-1=2. Instead of multiplying by 3, multiply it by 2ppt to raise it to the 3ppt end point.
I agree though, salt does have its uses and limits in our tanks. It is very helpful, but also very stressful if our fish were not designed to take an elevated salinity. It all depends on the fish and the overall salinity.
-Ryan
To determine how much salt to add into a given body of water here is a helpful formula:
gallons of water/125 x desired salinity (in ppt) = pounds of salt
Example:
100/125 x 3ppt = 2.4 pounds of sodium chloride to bring 100 gallons of water to a desired salinity of 3ppt (.03%). This is also assuming the water does not have a salinity to begin with. If it does, the formula is easily adjusted for this. Say it has 1ppt salinity and you want 3ppt. 3-1=2. Instead of multiplying by 3, multiply it by 2ppt to raise it to the 3ppt end point.
I agree though, salt does have its uses and limits in our tanks. It is very helpful, but also very stressful if our fish were not designed to take an elevated salinity. It all depends on the fish and the overall salinity.
-Ryan
