GH: dissolved minerals
General hardness, or GH, mainly reflects dissolved calcium and magnesium. Shrimp use minerals as they grow and form a new exoskeleton after molting. Very soft water can be a concern, but a failed molt should not automatically be blamed on GH alone.
Aquarium Co-Op lists a GH of at least 6 degrees as a practical reference for cherry shrimp. Test the source water and aquarium water, and check whether conditioner or remineralizer is changing the result.
KH: buffering capacity
Carbonate hardness, or KH, relates to water's ability to resist pH change. It is not the same measurement as GH, even though some products affect both. Aquarium Co-Op lists at least 2 degrees KH in its cherry shrimp care guide.
A stable pH depends on the whole setup, including source water and any materials added. A single pH reading cannot tell you whether KH is adequate or whether a change is underway.
Make changes slowly
Test with a kit that reports units you understand, then record readings over time. If your water is very soft, research a shrimp-specific remineralizer and follow its label. Do not add powders by guess or use TDS as a substitute for GH and KH.
When shrimp are already in the tank, gradual consistency is safer than trying to hit a perfect chart overnight. If readings differ sharply from the seller's water, plan acclimation with that difference in mind.
Use these as general hobby references. Test your aquarium and confirm product guidance before making changes.