Can't pass level 8-4

I have been playing for weeks. I can't get pass level 8-4. Any suggestions. It keeps sending me back to 8-1.

I got the same problem . It seems this level should the penultimate one rather than part way through almost .

This was extremely hard for me. I finally learned that there is some strategy to be played in this game and not just shoot as fast as you can to burst the bubbles, so to speak.
Practice on some of the lower levels to shoot through the line you just burst some bubbles in, to burst ones above it, always try to take note of what your second ball color is, or if you need too, reverse the colors to make this happen, this really makes the line back up and gets rid of more in a short period of time. Sometimes if you have the time, you can set up the colors so when you burst one set, the others coming together will burst also, once I got 4 sets to do this.
Also when you have the lightning rod thing, if you will left click, so you can save it when you have a line of onesies, of all the different colors.
If you are doing all this anyway, just keep on keeping on.
I finally made it through and actually got to Level 13-10 but could not beat that level, it is VICIOUS! LOL!! I have never heard of anyone beating it.

I know! I'm getting sick of level 8-4. Once I won it and then lost 8-5!! So I'm still going 8-1 to 8-4, trying to beat it again. Gets a bit old. 13 sounds vicious!