I would not use nopox in a 10 gallon for these reasons:
Nopox is a bacterial carbon source used to rapidly grow bacteria that can then be removed by a skimmer (preferably a wet skim) in order to lower nitrates and phosphates). This is handy as many people who have larger tanks would need massive amounts of water to change out in order to effectively lower nitrates and phosphates. In a 10 gallon, you can lower the nitrates and phosphates with significantly less water. Hypothetically, a 5g change will decrease those numbers in half in a 10g, while adding back good elements. Since a 10g has so little water, it would be so much more beneficial to simply change out the water than to do nopox. If you are having an algae problem, consider running some sort of phosphate media in a HOB filter if you have one.