I came home to two more deaths tonight. Last 5 remaining. Did a water change after dinner (around 35-40%) as well as squeezed the bio juices from my sons Whisper 3 (two large cartridges) into the mix post the water change.
I got Nitrate and Nitrite kits, so I will get measurements. Probably should have done that prior to water change, but.... oops.
Update -- Still 5 Cardinals and looking good. Nice grouping and eating. Clowns appear okay, though they don't come out of the underbelly of the driftwood much.
Thanks all for your input. hopefully new batch of cardninals will be arriving shortly to get me back to the dozen or so I want to get established.