2nd year SWG - trying to dial in maintenance #'s for Tampa Bay

[onemorekat]

I am trying to dial in a correct swg resulting in a good maintenance for this summer. This is the second year I've owned it and I am struggling to stop green algae.

Located in Tampa Bay, FL., near a very large oak tree (I remove debris daily) and full sunlight. 13,000 gallon marcite pool.

Testing equipment I have a TF100, Aqua CheK PH, FAC, TA, Stabilizer and a Taylor Salt test kit. Please help dial in maintenance based on today's test below in bold. And thank you in advance for any suggestions!

Per sgschlorinators.com my SWG Breeze 320 requirements are:

Salt (4000-4500) PPM

PH (7.2-7.6) PPM

Total Alkalinity (TA) (80-100) PPM

Cyanuric Acid (CYA) (20-50) PPM

Phosphates Metals (None)

Calcium Hardness (200-400) PPM

Free Chlorine (1.0-3.0) PPM

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Today's test prior to 5 gallons of chlorine to try to control start of yet another green algea bloom and prior two days of running pump and SWG 100% total 48 hrs.:


Salt (4000-4500) PPM ~~~ 4400 OK

PH (7.2-7.6) PPM ~~~ 7.8...always seems a little high no matter how much Muriatic Acid I add?

Total Alkalinity (TA) (80-100) PPM ~~~ 95 ppm OK

Cyanuric Acid (CYA) (20-50) PPM ~~~ (reading 100 ppm from pool store, but 40-50 ppm on my TF100???)

Phosphates Metals (None) varies between pool store tests 100-300 ppm - how do I test this? and treat?

Calcium Hardness (200-400) PPM ~~~ 300 ppm

Free Chlorine (1.0-3.0) PPM Pool store = 0, k1000 = ~~~ .5 ppm - How do I raise this number without carting 20 lbs. jugs of chlorine?

 

[pinguy]

Welcome to TFP!

First thing first, stop relying on the pool store's advice. Their testing is inaccurate and designed to sell you more chemicals than you need. Getting the TF100 is a great start, and is really the only tool you need to keep your pool crystal clear.

So lets tackle the algae. Getting rid of algae is not just adding a single dose of chlorine and hoping for the best. You need to SLAM your pool, which entails testing and adding chlorine on a daily basis until the water is clear and you pass the overnight free chlorine test. Check out this article for a great explanation: Pool School - SLAM - Shock Level And Maintain

For the rest of your questions:
PH: You lower PH with Muriatic Acid. Use pool math (http://www.troublefreepool.com/calc.html) to calculate the amount.
CYA: Trust your TF100, not the pool store. 40-50 is a little low for a SWG, but you don't want to bump it up until you complete your SLAM.
Phosphates: This is irrelevant to keeping a crystal clear pool. The pool store just wants to sell you useless chemicals. You can safely ignore this test result.
Free Chlorine: Aha! This is why your pool is green. You need to keep this number at around 4-6 ppm with your current CYA level (see chlorine/cya chart below). For slamming, you will need to cart around some jugs. But after things are all clear, the SWG will take over. Do not use powdered chlorine to SLAM. It will add huge amounts of CYA or Calcium, which will lead to further problems down the road.

Check out these articles as well:
Pool School - Chlorine / CYA Chart
Pool School - Recommended Levels
Pool School - How to Chlorinate Your Pool
Pool School - Recommended Pool Chemicals

 

[onemorekat]

Thank you!!!
My SWG recommends 30-50 ppm on CYA - would I follow the chart to slam for non-SWG i.e.:

CYA (Stabilizer)

Minimum FC

Target FC

Shock FC

40​	3​	5​	16 ​
50​	4​	6​	20 ​

Welcome to TFP!

First thing first, stop relying on the pool store's advice. Their testing is inaccurate and designed to sell you more chemicals than you need. Getting the TF100 is a great start, and is really the only tool you need to keep your pool crystal clear.

So lets tackle the algae. Getting rid of algae is not just adding a single dose of chlorine and hoping for the best. You need to SLAM your pool, which entails testing and adding chlorine on a daily basis until the water is clear and you pass the overnight free chlorine test. Check out this article for a great explanation: Pool School - SLAM - Shock Level And Maintain

For the rest of your questions:
PH: You lower PH with Muriatic Acid. Use pool math (http://www.troublefreepool.com/calc.html) to calculate the amount.
CYA: Trust your TF100, not the pool store. 40-50 is a little low for a SWG, but you don't want to bump it up until you complete your SLAM.
Phosphates: This are irrelevant to keeping a crystal clear pool. The pool store just wants to sell you useless chemicals. You can safely ignore this test result.
Free Chlorine: Aha! This is why your pool is green. You need to keep this number at around 4-6 ppm with your current CYA level (see chlorine/cya chart below). For slamming, you will need to cart around some jugs. But after things are all clear, the SWG will take over. Do not use powdered chlorine to SLAM. It will add huge amounts of CYA or Calcium, which will lead to further problems down the road.

Check out these articles as well:
Pool School - Chlorine / CYA Chart
Pool School - Recommended Levels
Pool School - How to Chlorinate Your Pool
Pool School - Recommended Pool Chemicals

 

[pinguy]

Thank you!!!
My SWG recommends 30-50 ppm on CYA - would I follow the chart to slam for non-SWG i.e.:

CYA (Stabilizer)

Minimum FC

Target FC

Shock FC

40​	3​	5​	16 ​
50​	4​	6​	20 ​

Yes, follow the non-SWG numbers.

We recommend higher CYA levels for SWGs to increase the life the the cell. Sometimes this goes against manufacture or pool store recommendations, but will not do any damage.

 

[onemorekat]

Awesome to know! I wasn't sure if higher cya would hurt cell and now I know. Thank you!!!

Yes, follow the non-SWG numbers.

We recommend higher CYA levels for SWGs to increase the life the the cell. Sometimes this goes against manufacture or pool store recommendations, but will not do any damage.

 

[pooldv]

Looking pretty good! And good info from pinguy!

Here are TFP's recommendations for your saltwater pool, Pool School - Water Balance for SWGs

Lowering your TA will help slow your PH rise. I would start at 80 and see how PH acts. If it still rises quickly go to 70, if it still rises go to 60. We definitely recommend CYA at 70-80 for SWG, especially in sunny florida. PH up to 7.8 is fine, just don't let it go higher.