seaweed question about refrigerating?

So i put a sheet of seaweed in the tank for my new sailfin the other day and she would not eat it from the clip. I pulled it out and didnt want to waste it so i put it in a small cup with some salt water and put it in the fridge. I mixed it up into little bites and suck some up with my turkey baster and squirted her a little and her and all my fish ate it right up!

my question is, is it ok to store it in the fridge in the water like this? Or will it go bad? Should i just mix up a little at a time and give it to them?

I only did this this time because there was a bunch in the tank and i did not want to waste it.

thanks guys