So this is embarrassing but if someone learns from this it's worth it. So this pool has a waterfall, and a dedicated pump for it. This pump pulls water from an infinity trough.
Some of you will have already realized what I did...but for everyone else...just wait for it.
So new to me pool, ehhh it's a water feature, no reason to run that as part of the cleaning cycle. We'll just run the other pump that pulls from the skimmer, vacuum pump and SWG.
So today I get to the pool with the intention of testing the water of the pool for FC, and adding bleach to get up to 6-7 ppm fc. And I'm startled by a infinity trough that has a bit of green in it. But that's not possible...oh wait...
Well lets turn on the pump and get some of that water going, and I'll pull a sample from the waterfall.
ZERO FC, completely ZERO.
In hindsight I probably could just "shocked" the small trough at that point. The pool as an overall is still at 4 ppm FC. I added what the pool math was telling me to in terms of bleach to raise the FC from 4 to 7, and I added it mainly to the trough to be circulated. Before leaving and after running the pump for roughly 30 minutes there was some improvement in clarity, but likely am in for it at this point.
It would be nice to not have to shock the entire pool, but that is definitely very likely in my very near future.
So that looks like I'll have to partially drain the pool to get the CYA levels down, and then SLAM the pool, which sounds....fun.
It'll likely depend on what the FC of the entire pool looks like tomorrow. If it's essentially zero tomorrow, or near zero then I get to start the fun. If it's green then again fun. If it's 4,5,6,7 then perhaps it's been saved...