Sidekiq: ERR max number of clients reached on heroku

[SupremeA]

I need to know how to fix or reset this error. I know you can pay for more connections but my app only has me testing in production. I don't believe the connections are closing which caused the problem. How do I fix this on heroku. Cant seem to find an answer other than increasing the concurrency in a sidekiq.yml file and that doesn't solve it

sidekiq.yml

# Configuration file for Sidekiq.
# Options here can still be overridden by cmd line args.
# Place this file at config/sidekiq.yml and Sidekiq will
# pick it up automatically.

:concurrency:  25
:timeout: 8

[mperham]

Set the concurrency lower, to 5 maybe.