I just bought a house with a sprinkler system, and I'm trying to make sure all the heads work and I have all the zones figured out.

A couple of the heads are broken, and need to be replaced. The system controller name is made by Hardie, but the heads are mostly hunter and some other brands mixed in.

What brand do I replace the heads with? Should I stick with hunter since that's what is on most of the system or does it not matter?

Also when you have to replace heads, is there a way to know you are replacing one with the same flow and spray size as the current broken head.

Last question, should the sprinkler heads that pop up rest at ground level or below ground level when not in use. Some of my heads are 4+ inches below ground...I'm not sure if I need risers or if that's the way they should be.

Any help would be appreciated, this is my first time working with a sprinkler system.

Thanks.