I am changing 30% of water in my puffer tank today but not sure of how much salt I should mix up in a container to add to the tank. The level is at 1.0012 salinity.
It varies depending on your water supply, add salt to just the water you are replacing and check it with a hydrometer to test it matches your tank water. I mix my brackish water the night before to be sure all the salt has dissolved and i get a true reading.
A very rough estimate is that it should take around a cup of marine salt/5g to raise the SG .005. Is that the SG it was at in the shop you got it from?
Thanks CFC that worked great. I mixed up the water and salt, tested a few times, within a half hour it was ready. Then I tested the tank and it was at the same salinity. I bought some silk plants for her tank and she is finally starting to swim around a little more instead of going up and down the side and back of the tank. So hopefully she will be more comfortable now with more places to hide.