Salt crystals formed in the bottom of my contact lens case?

You need to rinse and dry your contact lens case with clear water every day after you put your contacts in your eyes.

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I doubt that that is a good sign. Things crystallize when you have too much of something. I'm pretty sure the solution you have is balanced/in equilibrium and won't crystallize anything so I think your contact lens case was mixed with something. Rinse it out as often as you can so that doesn't happen again and it might scratch your contacts.

You can clean case with your contact lens cleaner using a brand new inexpensive toothbrush

I'm not too good about this stuff but i think that usually, if something is hurting you, you should check with the doctor, in this case, optician. Good Luck!