help needed: transparency texture vs water4

hey everyone! I kinda stuck with an odd problem: I've got my player ship shooting a missile with a "transparent-kind-of" explosing ( it's the heatwave from ben throop's detonator framework). everything is running fine, but when i add the water4 present into my scene, i get this annoying graphic issue:



you can clearly see the texture-box around the explosion. how can i solve this? :s