how much grin total supply?
Max supply is unknow like Ethereum.
Grin coin informationYou can join
Grin Observer topic. If you don't know, the admin of forum like this coin and accepts it as one of two payment methods for the forum Copper membership.
Coindesk has one article that explains
Grin coin's monetary policyMonetary Policy
The block reward is set to remain at 60 grin per block solved.
This causes grin to be inflationary at a decreasing rate. Grin will experience high levels of inflation in the early days as each block has a great impact on the circulating supply; as time goes on, this effect will decline.
Grin has a target block time of one block per minute, effectively resulting in 1 grin mined (created) every second. The community argues that sound money has more to do with a transparent emission schedule, than a capped supply. The system by design has no supply maximum limit.