you can add epsom salts, but since the Tiger has some mg to it, I can't guarantee epsom will solve the problem. On Peter's strength, alot of people think you need to cut back the nitrogen and mabey that's true, but I know someone who grew alot of plants using Peter's 20-20-20 and never changed anything. You might try to determine if cutting back on nitrogen in flower is really necessary. Maybe it's not. since there is a good deal of yellow I wonder if the lack of Nitrogen might be part of the problem. Once you have something that works it's probably best not to change it. A ppm meter would be a good thing to have, meaning you can put around 1200 or so ppm in a water container and then water with it in soil. Just be careful you don't water too much. Let the soil dry up some.