They do eat their eggs, but when Mr. U Tin Win visited the site where CPD's were originally discovered, he measured the water at pH of 7.3
Keep your water temperatures in the lower 70's F and you should be fine.
Feed the fry liquifry, greenwater, or pure spirulina powder( from an herb store. A little goes a long way- just dissolve it in water.) for the first day after free swimming, then for 2 days feed green water plus a teeny tiny bit of live microworms (or walterworms)... Over the next few days, decrease the greenwater dosing and increase the microworms. Then you can gradually wean them onto crushed flake... (I would reccomend feeding live food at least a couple times a week for the forst month of life so the adults will grow up to be colorful.) vinegar eels, are also great food since they'll survive days or weeks in freshwater.
As for your real question, they can spawn every 2 weeks, but you should really use a 'spawning tank' if you want fry... (Add females and males to a tank in a 2:1 ratio, leave them a week after their first spawn, and remove the adults to their original tank.