Hi!

Your 300 units S19 probably gives you 30000TH. If you consider 2-phase immersion cooling, you would get extra 12000TH out of your 300 units. However, immersion firmware for S19 isn't available on the market yet, you can use Control boards from S17 to overclock your miners.

Read more about my project here: https://bitcointalk.org/index.php?topic=5368372.msg58306691#msg58306691