TF happened here

Seedlings, this one is either a local Goo or (less likely) a Cindy cross... I mixed up the seeds. This twisting is occurring on both strains, but this is the plant that got it worst. My other strains/plants do not have this at all.
New growth curling occurred the day after a rainstorm, so I thought they were just over watered and I let them drink.
Condition did not improve the next day.
I typically water with dechlorinated tap water, pretty hard water though. Water pH typically 7-7.5.
No feedings since Tuesday, and it was just a dose of rhizo-blast. Watered Thursday, rain came Friday, which is why I attributed it to overwatering at first. Ended up being more rain than forecast.

My friend is of a mind that since it happened only to these, whose roots certainly touch bottom, leached up something from the pine stump they were sitting on...
They are due for a pot upgrade in two days, but I can't imagine them being rootbound, they've just started to show roots in the drain holes-- a couple healthy white root tips.

why are you watering them with water with a ph that high

It's what water is out here. It's literally bog standard; doesn't much disturb my soil pH.
Some folks out here run a filter, but most don't; there's a few tricks... My favorite is to force minerals and chlorine out by using hot water. Not while it's hot, of course. As the hot water cools, minerals precipitate out. Bubble it to put oxygen back in.

In the end, the plants are bouncing back, tested my runoff and had bottomed ph hard. I recall that the soil I used for them was old, maybe the buffer source became depleted....