The time to disqualify this judge and get a different judge was at the very beginning of the case, and it's no longer possible. You're stuck with this judge, unfortunately, so you need to figure out a way to get rulings that you want from him.
You need to get him to get your ex to prove the effort he's making to get a job, and if you think your ex is undertstating his income and overstating his expenses, it might help if you brought the judge documentation of that, rather than just just assert it orally. Similarly, because judges have so many cases at once, they can't be expected to remember thinsg about your case, so you want to put your situation and claims -- full time job, part time school, 1 car-- and your ex's --no job, 3 cars, owes $500 in kids' medical expenses, etc.-- in writing in a motion so the kidge can't ignore things so easily.
Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.