CYA Test

[natedogg]

Kinda, but I guess I can't tell what to start with. Should the pH be raised using soda ash first and then add stabilizer to up the CYA to target and then add bleach? I also can't understand what by weight or by volume means in the PoolMath fields. i figured by weight would mean that many oz in powder form, is that accurate?

Also i have a SWG, but am not sure if it operates as this is my first year owning the pool. Should I be SLAMing to target a SWG or just a regular chlorine pool. I figure the later to ensure proper levels in case the SWG is not working as it seems being under is safer than over, if that makes sense.

 

[triptyx]

I think you have some things mixed up. pH should be about 7.2 for the SLAM. Your CYA (stabilizer) will vary based on how much was added (i.e. 30, 40, 50, etc), then you increase FC based on that CYA level. An ideal example would be a CYA of 30, FC at 12, and pH at 7.2 during a SLAM. Make sense?

What he meant by stabilized was a Ph level that wasn't rising or falling out of control. I believe he's concerned that Ph will shift to a damaging level unnoticed while he's SLAMing.

 

[Texas Splash]

We thought from yesterday's posts you already added stabilizer. If not, you can place a sock with stabilizer in the water at any time. Do it right now if you need to ensure CYA is to at least 30 ppm. That doesn't effect anything else you do. Now since you highlighted you have a SWG, understand TFP recommends the CYA level be much higher - at least 70. It needs to be that high to protect the valuable FC created by your SWG. If your SWG is not operating at the moment, you can treat your pool like a "non-SWG" pool for now and leave the CYA at 30....for now. I didn't see anything to indicate you needed to SLAM yet (for algae) but if you do, then the lower CYA will be to your benefit.

Your FC should be around the 3-5 range. Never let it drop below 2 for now. And pH can be adjusted to the mid-7s. Since you're just increasing pH, you can do that at any time. Same with the bleach, add it right away near a return jet(s).

 

[natedogg]

yes, get the appropriate pH and then add the stabilizer to target CYA. My biggest confusion is how much of each product to buy based on the amounts shown in PoolMath. I put in 19K gallons and 6 for pH as I was below which gave 323 oz by weight. Am I reading that right as being roughly 20 lbs of baking soda?

 

[Texas Splash]

On the calculator, what I did was use a pH from 6.8 to 7.5. Best to go in baby-steps to not go too high. So then it tells me you need to add 72 ounces of soda ash or 144 ounces of borax to raise that pH.

Baking soda is used to raise TA.

 

[natedogg]

thanks! I will definitely be taking a cautious approach as your explanation makes more sense than what I was envisioning,