I think what you have put in your pool "super green" algaecide is an aglaecide that has copper in it. This being said, you may have a problem when you raise your chlorine to shock levels, as you may get some staining due to the copper in the algaecide which I read is 7%. Hopefully the algaecide has a sequesterer in it that keeps the copper in suspension. It really is not a good idea to introduce any metals in the water. High chlorine levels will kill any algae, you just have to keep it high enough long enough for it to do the job. With a cya of 40 you need to take your chlorine levels up to 15ppms and keep it there being very consistant. Everytime it falls below 15ppms, you have to add enough chlorine to take it back to 15. If you read through this thread, you will see this algae sometimes needs even higher levels of chlorine to kill it. I would suggest that you take your chlorine up to 15 - 20ppms and keep there, brushing and backwashing as needed. Be very consistant!!! You may want to drop your ph down to 7.2 while you are shocking the pool to help keep staining away. If you are consistant with the high chlorine levels, and keep your filter running 24/7, you should be able to get rid of this once and for all