Can I REUSE an alginate bath for reverse spherification? If I use a solution of alginate today, can I use the same solution next week? How should it be optimally stored? How long will it keep. How many "spheres" can be produced by a batch of alginate?
This site say you can use it again, just make sure you strain it before you store it http://www.molecularmixology.co.uk/index.php?act=viewRecipe&recipeId=34
This site says you can store it for a couple of days in the fridge http://www.molecularrecipes.com/spherification/7-tips-making-spherification-caviar/
As for how many spheres can be produced - I'm afraid that would be completely dependent on how large you make your spheres.