You can drill out the holes on the attachment just the smallest of hairs bigger and the spray won't be nearly as high. Start with the smallest diameter drill bit that would increase the hole size the least, then test. If the spay is still too high and spilling out over your basin again drill the holes just a hair bigger until you get the height you want with no overspray. Be careful and increase the hole size in the smallest amount possible. If you drill out the holes to large, you'll lose all of your height.
I wish I did have a written step-by-step guide but I actually never made one. One suggestion would be to read the closed captions along with the video, and hopefully that can give you a better idea of what to do.
I had to play around with it but I just made sure I pulled the zip tie really tight against the fence, and it was attached to the wire of the solar panel