feed them baby guppy food and make sure your filter can't suck them up. If it can, get one of those little tank attachments and put them in there until they get bigger maybe. When my betta had her babies, i attached a piece of foam around the filter intake, it didn't hurt the sucking power, but it lessened the chances of the babies getting sucked up. Also, keep an eye on the parents, they may try to eat the babies, im not too sure though. good luck!