Optimal on Canal looks like this near as I can tell.
It does not lose out to fastest possible Granary micro in the final

total.
T55 - Whip Workboat, work Clam + coast
T56 - Granary, Clam + coast
T57 - Granary, Clam + Crab
T58 - T59 Granary, 3 seafood
T60 - Whip Granary, Clam + Crab 12/24
Halt Growth
T61 - Lighthouse, Clam + Crab 18/24

T62 - Lighthouse, Clam + Crab 24/24
Resume Growth button
T63 - Lighthouse, 3 seafood (1 of them is not improved) 18/26
T65 - 2pop whip Lighthouse (65/60

) 17/24

+6

per turn
Improving that last seafood makes Canal grow too fast and adds a whip anger.
The city works well at +9

per turn working more coastal tiles.
This micro has a lot of constant
per turn and not much fail gold
If we want Canal City to contribute to fail gold, 2-pop whipping a Worker after Lighthouse at 29/60

generates a ton of hammers since the city can put 10

per turn into a Worker.
This means no on early Library.
Still, on T69 it could start a Worker at +10

per turn at Size 4 (24/28

), and when the Worker is whipped T72 at 29/60

, the city will still regrow to Size 3 when it produces Worker. (naturally occurs with 24/24

when building worker)