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# Shall I change the full amount of the cover medium or just partially?

Changing 100% of the cover medium might cause the disruption of the hydrogel. We recommend adding additional fresh medium without removing the top medium for the first medium change. Afterward, change 50-80% of the cover medium. (Please check the recommended volume of additional cover medium in Table below.)

![](https://storage.crisp.chat/users/helpdesk/website/16e3d682039ef000/faq-30-table_uctkyn.png)