+1 on diy coral snowI use Coral Snow as well, sort of. I use a DIY version that works just as well.. KZ Coral Snow is really expensive, have you looked into this
https://www.reef2reef.com/threads/diy-kz-coral-snow-with-97-purity.211722/
It's what I use, it's basically the same thing but way cheaper, you can get a 97% purity 5 pound bag of CaCO3 (KZ coral snow) for 12 bucks on Amazon. I'm pretty sure a 5 pound bag will last me a lifetime, if you're interested read through the thread, if you switch you'll save a lot.
Stuff is awesome