Ok, so I flushed for a day. Then I replaced the flushing water with new water. I did a 50/50 mix of tiger bloom and grow big, overshot the EC slightly, to 1.26. I brought the ph to 5.8 almost precisely.

The plant has been doing just fine lately, no new curling leaves and the purple stems are turning back to green. I haven't added anything aside from the nutes, although in a couple days I'll add the earth juice catalyst again.

Any suggestions are welcome.