Aw, I'm sorry to hear Nikkita has crystals.

I wonder if you know the importance of knowing if her PH is high or low and the ways you can attempt to keep that level. Sometimes keeping the PH levels correct can go a long way to hold off the UTI and crystals issues.

I've done quite a bit of research and asking around about UTI issues because of the problems I had with Tiger Lily, whom I ultimately had to re-home due to her stress of living with other cats and the escalating fighting problems between her and Molly and Kit.

Cats with urinary issues should eat all wet food, no dry. Knowing the PH and finding ways to keep it at the right levels is also very important. None of that helped with Tiger Lily's stress levels, though. And it was her stress that kept throwing her PH off. She never had crystals. But the PH being off can lead to crystals.

If Nikkita's issue is high PH you might want to have the water you use tested to see what the PH in that is. If it's higher than 6.5, you might want to try to find a bottled water to use or invest in some kind of filter that lowers PH(I don't even know if there is such a thing, though). As well as learning what foods promote a healthy PH level.