To my knowledge, there is no legal obligation involving informal relationships. If you are happy to give or share anything, you are free to do so. The other party has no legal power to demand anything. There is an exception though if the girl/boy is under 18 because it is a crime to take a minor away from parents regardless of the minor's consent. In this case, you might need to cut a deal with the family before the authority learns about it because it is punishable by imprisonment. Some poor families might even trick people into doing that for a six figure compensation. Others might be willing to end this unfortunate circumstance by getting them married to avoid gossip.
I spent over 10,000 baht on a filtration system + filter replacement. The filters clogged up very fast, and then either the water output slowed down, or the water quality began to drop. My dad regularly buys 10-baht blue gallons of water, so I used the water quality tester to test it and found that it was even better than my machine. So, I quit using private filtration and started buying these gallons since then.