Some advice for a new Bath Bomb maker - cracking bombs


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New Member
Apr 29, 2018
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I started making them about 3 weeks ago and have been experimenting with my recipe and different ingredients nonstop since then. Ive ironed out a million mistakes so far, but now I'm having another issue!
They pack and mold perfectly, fizz like a dream... but after they dry, they crack! Usually a huge crack right in the middle of the bomb where the two molds meet and then it starts cracking outwards from there and will even fall apart on it's own after a week or so.
Picture after 2 days:

I've been doing a lot of research and my ideas are maybe I'm adding too much water? I wet it until it feels like what I consider to be wet sand, but I think I might be overdoing it. I also live in the south so humidity very well could be a problem, but even on the days it's only 30%-40% outside I have issues. I wanted to seek some advice before using more ingredients and would very much appreciate some help with my recipe overall. :D

1cup Baking Soda
1/2cup Citric Acid
1/4cup Tartar
1/4cup Cornstarch (sometimes I do this, sometimes I don't. Seems to make them much lighter)
1/2teaspoon Coconut Oil
1/2teaspoon Polysorbate 80
1/2teaspoon Essential Oil
"Holi Color Powder - Chameleon Colors" dry dye
A spray bottle of brewed tea or water, spritzing until wet enough. I'd estimate around 6-8 spritz (should I switch to witch hazel?)

Thank you so much