I had one too. I boiled 1/4 tsp epson salt in a small pot (to dissolve it & let it cool overnight) and added it to my plain ph water - i didn't give nutes. I didn't use a gallon, probably 2 liters. The spots on the leaves shrunk and the green came back to some that were yellow but some were too far gone and are going to drop. my plant only has a few more weeks left till it's done flowering so I don't care too much but i would like to keep her healthy.