Pls take few time to see the video first, following is the difference for your reference:
1. 0.5mm can filter faster than 0.3mm
2. 0.3mm can get more water color oil than 0.5mm
3. the second stage of oil color with 0.3mm is much clear nad brighter than o.5mm’s second stage
4. 0.3mm’s oil absorption rate a bit higher than 0.5mm