It can take several business days for your eCheck transfer to complete and the recipient can use the funds from your payment. Here are estimates based on which country your bank account is from.
U.S. - up to 4 Business days
Canada - up to 8 Business days
UK - up to 9 Business days
Australia - 7-8 Business days
Your eCheck payment does not appear in your recipient's balance until the transfer is complete.
If you have any further questions I would encourage you to contact PayPal directly for them to explain the timeline of clearance.