Or perhaps, how about decreasing the maximum number of turns on hand to half the normal, and transferring the remaining turns into stored turns on declaration of war. This could occur instead of dropping stored turns on 0 and potentially "losing" turns. Besides, if stored turns are just dropped to 0, it'll make it more likely for people to want to FS once 120 turns are stored (sooner, without warning). Whereas the latter still promotes the storing of turns, but would require a clan to be more actively participate in the war. Moreover, if the number of turns on hand during the war is reduced, it'll reduce the time people spend on their countries daily, making it more likely they'll play more often (possibly).

E.g. 120(0) becomes 60(60). 120(40) becomes 60(100). And you'd only be allowed to hold 60 turns on hand at any one time while the war declaration is in effect (granted yes you should still be allowed to get bonuses such as the 18hour bonus and bonus points in turns which could easily push the 60 turns to around 66-70 or more turns on hand).

Thoughts?