So I built this loop last summer and filled the reservoir to about 90% capacity. By now, the water level has gone down to about 75% so I would like to top it back off. I originally filled it with a EK Cryofuel clear and was wondering can I just use more of the same Cryofuel to top it back off or not? The bottle I have says not to mix it with other liquids, but does not specify if I can mix it with another bottle of Cryofuel. Thanks!