Ok I see what you’re trying to do. After your color ramp –> multiply nodes, add a Mix RGB node and plug your multiply output into the factor of the new Mix RGB, then Mix RGB into your Transparent BSDF.
From there you can tweak the color swatches of your Mix RGB to get your great caustics. I’m not sure the order, but I think one should be white and one should be the green color you’re after.
