Clarification on Clay Credits Usage with 'Find People' Tool

Newbie clay credits question. When you use the 'find people' tool when creating a new table I can't see anywhere that it says it uses any credits so I used up quite a lot there by accident. I've created quite a big list now by accident. There are no further enrichments but I seem to have used a further 3,000 credits just by filtering this master list. I've now learned the lesson of auto update but I can't see how I've used those 3,000 credits just by filtering??