You can do that if you feed them very, very small amounts at both feedings. I don't think 3 times is necessary. You have to be careful not to overfeed your fish. Uneaten food is not good for the tank!
Most people also give their fish 1 fasting day! Hope that helps
I feed 5-6 times a week. once a day on the days I feed them. Adult fish can easily go a full week without being fed on occasions. That's important to remember if you go on vacation... The fish would be better not being fed than to be overfed by whomever you could find to do it.
Live plants help also as they provide microorganisms and even a bit of algae that the fish can graze on - which platies and mollies do a fair amount of.
Fish are much healthier when they eat less than when they eat more. Overfeeding could cause them to have liver and kidney problems. Its bad news. remember a fishs stomach is about as big as its eyeball. look at that flake in your hand and ask youself is it about as big as his eyeball. Most flakes can easily feed 4 tetras. the rule is the same with about any fish food.