How can I preserve seawater and sand?

[OUCaptain]

I've got this small glass bottle, about 2-3 oz, of sand and seawater that I think is mostly free of visible creatures. I want to preserver it the best I can without it turning all yellow, green or who knows what color. I was thinking of just adding a drop or two of bleach before capping and waxing the cap.

Any better ideas?

One more thing just occurred to me. Is there anything I can add to keep the super small particulate from floating around. Once it's sealed, I don't want it sticking to the glass and making it permanently foggy. I got to thinking about all this after I remembered all it takes to keep my saltwater tank going.

I'm beginning to why the trinkets they sell are filled with tap water and filtered sand from the hardware store.

 

[Eli]

That would work. Probably just a drop.

 

[TraumaRN]

Dont let it be exposed to temperature extreme either. I've got bottles of sand/water from 3 places in Australia for years now, little bit of bleach, keep them away from sunlight, waxed top. No problems

 

[OUCaptain]

I'm hoping it'll be that easy. Thanks! I'm giving it as a gift so I kinda want to be assured it will stay good.