Pool Math Goals

[lblomq]

I replaced my SWG cell and refilled my pool a few weeks ago and have been trying to get the chemicals balanced since then. Here are my numbers today as tested in the local pool store:
FAC: 5
TAC: 5
Salt: 4000
CH: 180
CYA: 70
TA: 100
pH: 8
Temp:62 degrees F

Pool Math calculates my CSI to be -0.16 with a suggested goal of -1, but the comments in the field to the right say anything less than -0.6 is suggestive of problems for plaster, tile, stone, and pebble pools. Why would it suggest a goal lower than a safe level, and how are the goals set in Pool Math? In the Suggested Goal Levels field I selected TroubleFreePool.com but in the pool surface drop down there is no option for pebble sheen, so pH, TA, CH, and CYA all show Goal: Not Setup. Is one of the options in the drop down have the same target values as pebble sheen? According to the pool store and from what I've read here on TFP, the CH is low but I'm leery of raising it since my water is very hard and in the past regularly had calcium buildup in the cell. Any suggestions on how to set the goals in Pool Math and save them is appreciated!

 

[Texas Splash]

Hello! For your Poolmath set-up, simply chose "Plaster". Now for the negative CSI, remember the reason some people might chose to go further to the left (negative) is if their other 3 scale factors (CH, pH, and TA) are high - either all of them or in-part. For example, if we were to trust those test results above, your pH is elevated which increases CSI very fast. Even your TA could be a little lower if you needed it to be. But since your CH is low, the elevated pH helps to balance you out for CSI. In Poolmath, experiment with entries and you'll see that if your CH was (for example) 350, and TA was 120 and pH about 8 that your CSI would jump quickly, increasing the potential for scale. Many years and thousands of experiments have led to the development of the TFP Recommended Levels and Poolmath data, so you can trust them.

Now for your testing ...... pool store testing is almost always incorrect. Various factors such as improper lighting, seasonal-trained employees, and the pool industry's goal to push their products for sales almost always pushes pool owners in the wrong direction. You would be better-served to obtain either a Taylor K-2006C or TF-100 test kit (link below). Don't let the free testing fool you, it's almost always full of flaws.

You're correct about CH in your area. Don't try to increase it at this point. Simply adjust TA and pH (together) in such a way that your CSI remains in a healthy area close to zero or slightly below. Unless you fill with softened water, I suspect your CH will climb quickly with summer refills, so at some point you may find yourself adjusting TA and pH lower to compensate. Hope that helps and makes sense. If you have anymore questions, let us know. Have a nice weekend.