Pool School Complete

[Spyderagent]

Hello,

We had pool school yesterday with our brand new build. I learned a lot, but water chemistry was very light in coverage to say the least.

Pool Details:

in-line chlorinator
11k gallons give or take
Stonescape minipebble plaster applied March 12

We ventured out yesterday to buy the following pool chemicals. Please let me know if we don’t even need some of these so we can return, not sure with having the in-line chlorinator:

4 gallons liquid chlorine
3” pucks
Soda ash
Hardness Plus
Muriatic acid
Shock packets
Conditioner

I ordered the TF100 test kit awhile back and we did our first full chemistry test this afternoon. The results:

FC 5
TA 50
CYA 30
PH 6.8
CH 225
CSI -1.32

I inputed all this into PoolMath app and immediately wanted to address the PH first, so I sprinkled 2 lbs 2 oz of soda ash into the pool just now as directed by poolmath.

I then wanted to address the calcium hardness, but I was reading the directions on the chemical packaging and it said to not add the same day as soda ash. Is this true? I held off on that to be sure. I’ll try that tomorrow I guess? Do I need to do another full chemistry test before I do tomorrow?

I then moved onto my TA, but realized we do not have 5 lbs of baking soda, so I’ll grab that tonight or tomorrow morning. Again, do I do another round of tests tomorrow before?

My CSI has me worried as it suggests corrosion could occur. Is my CSI calculated based on all the other chemical levels? If so, I’m assuming that once my other chemicals get brought into range, this will normalize?

Any other things I’m missing? My free chlorine is kind of on the high side, so should I dial down my in-line chlorinator a bit, too?

Any help or pointers y’all have would be greatly appreciated. I’ve been reading on this forum since pool construction began and have learned sooooo much valuable information. Wonderful resource. Thanks again.

 

[Texas Splash]

Okay, so you have a new pool (new plaster) and we know that the water should not be too aggressive (low CSI) for the first month or so as it cures. So yes, get that pH up to about 7.5-7.6. I would not leave the pH below 7.4 at this time. Now you'll find that if you increase the TA a bit more to say 70-80, the pH may climb fairly quickly. Whatever you add, let it mix for about 30-40 min then test again to see where you're at. While your CH is a bit low, your local water may be very hard and increase it with evaporation refills. But you can add a little calcium if you like or sanitize with some cal-hypo packets from the pool store. Right now your CYA is as low as you want it, and in a week or two you may want the CYA more at 40 as we warm up. So if those shock packets are trichlor or dichlor (stabilizer filled), you can use those. You can even use pucks (for now) which we know have stabilizer in them. Use them for a couple weeks or so, then test the CYA again. in the summer you'll want your CYA at about 50 and no lower than 40. Once you have the CYA at 40 or 50, switch to liquid chlorine only (or regular bleach) and store the tablets.

Go slow with the soda ash/baking soda to try and avoid a yo-yo process with pH bouncing up & down. If you can get the pH to about 7.6 and the TA to about 70-ish, things should be good for a while. Continue to use the PoolMath tool or APP and refer to the recommend chemicals link below in my sig to help. Don't forget to update your signature as well.