Sodium Alginate and Calcium Chloride
Calcium Chloride can often be found in the bulk sections at Coops.
Sodium Alginate is harder to find as it's only home use is probably making "spheres" with the above...I've gotten it off amazon.
This is harder to do than cooking shows make it look btw. I never could get the gels to stay for long. I'm not all that good a cook though either.