Hi,
I'm just learning about how to properly fertilize plants. Seeing as how my water is extremely soft with no KH or GH, I need to add calcium and magnesium besides other fertilizers. I know I can use epsom salts to get magnesium, and baking soda to add carbonates, but what would be a good way to provide calcium? Is regular white chalk pure enough to crush and use? Or are there other easily accessible sources?

Caclium sulfate works better: gypsum

Or you can buy the GH booster from Alan: aquariumfertilizer/com

Regards,
Tom Barr

It seems like GH booster is often recommended. If it's not available, can magnesium sulfate, calcium sulfate and baking soda be an alternative? If yes, how much of each should be dosed for a 50g? Thanks!

Remember that baking soda is a KH Booster, not a GH Booster.