Hi @antonopo and @Tek_Chand
I recommend you to check my solution in this topic about how to configure Index Life cycle Policy:
https://discuss.elastic.co/t/how-to-configure-my-index-life-cycle-policy/193468/3?u=dgonzalezp
This configuration was made to delete indexes older than 10 days, you just have to change it to 7 days and others parameters like index name, index pattern name...
And this configuration will be apllied to the new indexes, the olders ones must be deleted manually.
If you need more help just let me know.