Question regarding Pool School suggested levels and Pool Math

[aboykin2269]

Good morning everyone. I just tested my water for the first time yesterday evenning. First time pool owner.
Here are my #'s
FC 1.5
CC 1
PH 7.3
TA 100
CH 175
HCL 3600

So my questions is this: From Pool School the suggested levels are as follows:

To summarize:
FC 4-6 ppm
PH 7.5-7.8
TA 60-80
CH

• 50-300 for vinyl
• 220-320 for fiberglass
• 250-350 for plaster

CYA 70-80
Salt 200-400 ppm ABOVE recommended optimum level


And Pool Math shows suggested FC leves for SWG at 2.

SWG:2 Normal: 3 to 6 Shock: 12 Mustard Algae Shock: 19 Suggested target FC levels based on the current CYA level for outdoor pools. Note: Be careful if your CYA is really and truly zero!

So why the disparity? Which one do I need to shoot for (2 or 6) or am i miss-reading this?

 

[JohnT]

Those numbers in Pool Math are based on the value entered in the current value field for CYA. If you change that value to 80, the recommended levels will change too.

 

[aboykin2269]

OH I see that now. So based on CC of 1 and FC of 1.5, I probably need to SLAM right? The water is cloudy and has a slight green tint.
Also, I need to get my CYA up to 70 or 80 before beggining the SLAM, correct?

Thanks,

 

[PAGirl]

If you are going to slam, wait to raise CYA. you will need less chlorine that way. After the slam you can up it. Also, they recommend turning off the SWG and manually adding the chlorine.

 

[Divin Dave]

You need to slam.

Leave your CYA where it is. The higher the CYA, the more chlorine you need to get to SLAM Level.

Adjust your pH to 7.2 before you start.

Read the slam instructions until you comprehend it. the 'm' in SLAM stands for Maintain. You need to maintain FC slam level until you pass all 3 criteria for completing it. If you hit it hard and stay on top of it the first 2 or 3 days, it will go by quick. If not, then it will just take a lot longer.

Pool School - SLAM - Shock Level And Maintain

Pool School - Chlorine / CYA Chart

 

[aboykin2269]

Thanks. Another quick question Divin Dave. On the Chlorine CYA chart, for a SWG, they only list SLAM levels for CYA of 70 or 80. Do I use the Non-SWG chart for my SLAM FC level? Which would be 12ppm?

 

[pooldv]

Yes, use the non-SWG numbers for your SLAM.

Here is a more in depth discussion for SWG water balance for after you finish SLAMing.
Pool School - Water Balance for SWGs