If I petition family court for my child's father to pay more child support, could it actually go down because he has 3 more children?

I'm not an attorney but they can only take 17% of his pay per child but then again if you're doing that you're taking food out of the other kids mouth 2 I don't know your situation just figured I'd throw it out there as he needs to be able to support his other kids himself

I'm not an attorney. Only they could answer this type of question.