Sweetheart melons.. what do I feed it on?

[Grandma]

I am growing Sweetheart melons for the first time in my greenhouse. I only have one plant, in a pot, and it has 5 lovely sized melons on it and I'm very pleased with myself. I am supposed to feed it once the fruit appears but what do I feed it on? I asked my husband what should I feed my melons on. His reply was chocolate as my melons love chocolate! I suppose I asked for that!

So, is there anyone who could tell me the best feed to use? Also, at what point is the fruit ready to pick? This is my first time here so I hope this post is in its right place. Thankyou so much for any help.
Teresa