My first time posting numbers, Please Advise

[EskimoPie]

Hi y'all...

I'm using the TF-100 and my pool finished construction in mid-late August (details in sig). My CH since startup has always been ~100 and my CYA was ~50. I recently spoke with my PB about this and they sent out a crew to increase the CH and CYA both. My numbers now are:

FC: 10.5
CC: 0.5
TC: 11.0
pH: 7.6
T/A: 100
CH: 220
CYA: 100
Temp: 81

My FC is high because I tested earlier today and showed 0.0 FC and CC so I dumped in 2 jugs of Chlorine (probably shoulda just used 1). A test a week ago showed 5.5 FC and 0.0 CC. Obviously this shocked me and I discovered that my SWCG was putting out a Low Salt warning and reading 0 PPM salt. I know this isn't right since I've tested w/ the salt strips and am ~3700 PPM of salt. The SWCG has been working fine until now. It either took a Crud, or the recent addition of CH and CYA messed with it (is this possible)? I'm kind of kicking myself for even asking the PB to adjust my chemestry since they overshot the CYA (he said he wanted it to be ~80) and seem to have way under-shot the CH (not to mention screwing up my SWCG).

Anyway, putting these numbers into the pool calculator says I'm at a CSI of -0.34 which says is at risk of plaster corrosion. Is this still a risk w/ PebbleTec? It looks like I'll need to bump my CH up to ~420 to get a good CSI. Is this the right thing to do? Anyway, looking for a little guidance here... It's my first pool and this website has been a huge resource.

THANKS!

 

[JasonLion]

CYA of 100 is too high. You want that around 60-80. If you close for the winter then it should go down either from the partial drain of the over the winter effect so no need to deal with it now. If you don't close for the winter then you should lower that right off.

With a CYA of 100 and a SWG your FC target is around 5 or 6 when the SWG is working and 10 when it isn't.

Yes, you should pay attention to the CSI with pebble-tec. However, -0.34 isn't too bad. In the long run you want to bring your CH up into the 300s. In the mean time you shouldn't have any problems as long as your PH doesn't get extremely low. Since your PH will tend to rise over time, the risk of that isn't very high.

I would allow the TA to drift down, which it will probably do naturally, to about 70. That will slow the rate of PH rise and allow you to add acid less frequently.

It does sound like there is something wrong with the SWG. Make sure the cable to the cell is properly connected at both ends and try turning it off and back on again. The only other thing you can try yourself would be to check the blades in the cell to see if they are covered with white deposits. They should look like metal, if they are white they need to be cleaned (though I doubt this is an issue for you right now, it is still worth being in the habit of checking the blades every season at least). If none of those turn up anything have the PB fix it.