Hard Water +REP

Hi guys ive just noticed that my tap water is coming out at around 200ppm, is this bad for my plants??

It depends what is in it. Usually the chlorine will be a little high when it first comes out, but if you let it sit for a day or two a lot of that will go away. A trick I found is to run the water out of the cold tap, it usually has fewer deposits than the hot tap. If your plants aren't suffering, it should be ok to use. To know exactly what is in it, you might be able to send a sample to a lab for analysis (that will probably cost a good deal of $$$). If your plants are fine, cust keep the tap ppm count in mind when you are checking the levels for your nutes. Hope that helps.

my plants have had some problems that i couldnt figure out, and i get alot of salt buildup on my hydroton?

Have you been letting the water sit out for a day or two? If not that might make a difference because the chlorine will attack the plants. Of course, ph and overwatering can be an issue as well, but one of the best things to do is get to a good base, basically and blank canvas, so that way you know exactly what is going into the plants. Distilled water is good to use, but the costs add up kinda quick, especially on multi plant grows. RO filters can be installed in your home plumbing, the upfront costs are pretty higher, but it will pay for itself later since you are getting 0 ppm water for the same cost as tap water (roughly). Another option is a 0 ppm filter (like ZeroFilter) but you have to buy replacement filters for it.