The tank is back to a 3 day blackout.
Turns out the spirogyra algae has an attitude. It's hard to get rid of (according to other people on here, apparently it's THE hardest algae to get rid of, joy. It loves good water conditions). The tank was fine for a day or two post-blackout, and then the algae came back en masse. So I'm going all-out on the algae: blackout, Excel, reduced ferts, reduced photoperiod for a few days.
Keep your fingers crossed that I'll be able to kick it. I'd hate to lose this 'scape. Where will my little shrimps live when they get here?
@Destroyer551 - thanks! You probably won't want any trimmings until after I'm sure the spirogyra is gone.
@Lindo - I've noticed that the Hagen Mini is very sensitive to things blocking the vents and/or sponge. A few tiny plant leaves are enough to cut bubble production in mine, so I rinse the sponge media frequently to clear it. That, and you need the venturi valve plugged in and open for maximum bubbling.