Whilst there are many hot spring resorts in Calamba from as low as fifty pesos entrance ( you get what you pay for)we recently visited a Korean owned and operated spa.
you may wish to visit.
1 Its P500. day entrance pp until 10pm
2 Hot spa's are nice from 36C to 44C
3 Food is very average about P300 a meal ,very small menu and officially you cannot bring your own food. (maybe snacks and sandwiches) You may wish to eat out and come back. Mango/fruit shake /juice is expensive P150 but coffee and other drinks are about standard price
4 Accommodation is below average (and a bit expensive for what you get) so a day trip is probably best
5 the gardens hot springs and the pools are the real attraction.
6 90% of clients are Korean but other nationalities are not discouraged
7 Free hot and cold water is dispensed and therefore if you bring your own instant coffee/ tea or sunquick concentrate ( have you tried the lipton 3 in 1? Its like strong sweet uk tea, the kind they give you after a shock) its free...cups are provided
8.. getting there from Manila . By car 1hr - 1.30 mns depending on traffic By bus about 2 hrs...Bus drops you at the door of the resort which is one of the LAST resorts in the town. Map can be downloaded from the website.
Enjoy...we did :)