One sure way to ensure you have endless ongoing problems with your reticulation is to use 19ml black poly for your mainline.
By ‘mainline’ I mean the bit that joins all the solenoids. This is the part of the reticulation that is regularly under pressure and a 19ml ratchet clamp just isn’t going to cut the mustard when it comes to holding things together.
So by all means use black poly in your garden beds and even in your lawn if you prefer it, but only use good quality 25ml pvc in the mainline and seal the joints with green glue (rather than blue).
If you do this right the first time then it will save you a lot of grief in the future. If you don’t then you can expect your system to be popping and leaking and giving you endless trouble.
It might seem like you can save some money when you set out to do it, but the ongoing hassles will mean you soon regret whatever small savings you may have made.