Hi, and welcome to TFP.
Liquid chlorine can indeed be safely used with ANY pool surface. Just pour it in SLOWLY in front of a return with the pump running.
Strips are notoriously inaccurate. I am not sure what other kit you are using. Your best bet would be to invest in a good test kit (we recommend the Taylor K-2006, available online, or the TF-100, link in my signature) It will save you a ton of money, especially if you have been using lithium!!
Until you can get a kit, go to the pool store and have your water tested. DON"T BUY ANYTHING! come back here and post your results, and we'll be glad to assist you in clearing up your green pool.
Meanwhile, go to Pool School, linked in my sig, and read and re-read everything there!