looks awesome! great work...
2 things... one, you should be able to put that hammer in high flow... all coral generally can take more flow than we give them credit for... as long as it's not, like RIGHT in front of a powerhead, you should be fine.
also, it's great to see your sailfin and yellow getting along, that's great... now that they're teamed up though, adding a gem tang would likely cause major issues, and likely they would be for the gem tang. just a cautionary note.
keep up the excellent work! and pictures!