Calculation of Florida child support uses the net incomes of both parents.
When calculating Florida child support, the judge must "impute" income to a parent who is voluntarily unemployed or underemployed, unless the lack of employment is the result of the spouse's physical incapacity or other circumstances beyond the parent's control. That means that the reason the unemployed parent is unemployed is important. Company cutbacks are beyond a parent's control; being fired for cause is not.
Once it is established that the unemployment is based on reasons beyond the parent's control, the unemployed parent has to prove that s/he is using the best efforts to get another job. Judges want to see more than the minimal job search required for unemployment. Use all the means and methods you have to find work and be prepared to prove you've made your best efforts if you want to avoid imputed income or modify Florida child support.
If you've made your best efforts to find work and remain unemployed, the court will calculate your initial Florida child support based on your unemployment check and will likely order you to recalculate it once you get another job. In other words, if the modification of child support is granted it will only be a temporary modification. That's because once the child support amount is ordered, you must show that the substantial change of circumstances is permanent. The economy is not so bad that unemployment is permanent.
Bottom line, assuming that you've done all you can to get a job and the reason for your unemployment is not voluntary on your part, you can petition for a temporary increase or reduction of Florida child support.