Tyre slush in winter .

[FirstV8]

I ride my bikes daily , Mtb with road slicks and my Mtb with Maxis tyres filled with 80ml of slush . I regularly top up after i see wet patches on on my tyres so i know im covered if i puncture . My bikes are  stored indoors on cold tiled floors . Does the slush dry out/solidify or other during winter more than in summer when temps are higher . Do i need to do more tyre maintenance . This is first winter with Mtb bikes .