My first official SLAM... the TFP way

[Krutz]

OK people, I'm about to do my first official SLAM after studying posts on this site. My pool levels are pretty on point for the most part but my phosphate level is at 500 which is why I feel like algae keeps coming back on the walls within 2 days of scrubbing, despite having high FC levels (8ppm).

The pool shop suggested that I add PhosFree to remove phosphates but after studying on this site it sounds like i just need to SLAM it. Let me know if I'm on the right track. Here are my readings as of last night:
-FC: 8
-PH: 7.6
-TA 70 ( I added 2 lbs of baking soda this morning to raise this)
-CYA 80 (I am in Austin, TX and my pool gets full sun so I think this is fine but tell me if it's too high)
-Phosphate 500
-Current Pool temp 85 degrees F
Water is clear but Algae grows quickly on walls. 14,000 Gallon plaster pool

Pool math suggests that I have a FC SLAM target of 28 PPM. I am using 10% liquid Chlorine and I will be adding 4 .3 gallons of liquid Chlorine. Is this what I should be doing or should I just go with the PhosFree stuff to remove phosphates?

Thanks!

 

[mknauss]

Phosphates are algae food. If you have no algae, they do not matter. In rare cases, treating for phosphates makes sense. But not using the cheap stuff from pool stores. There is proper chemicals available. Though that is not your issue.
What test kit are you using? Please add that to your signature.
A non-SWCG pool should not have your level of CYA. It makes maintaining your FC in the target level of 9-11 ppm difficult. Up to you.
Your SLAM level FC is 31ppm. Prior to starting your SLAM lower your pH to 7.2. Maintain your 31 ppm FC as often as possible until you pass the three criteria.
Your TA of 70 ppm was fine. By adding baking soda you have now raised it so your pH will rise quicker and you will be adding acid to lower your pH and thus your TA.

 

[Krutz]

Phosphates are algae food. If you have no algae, they do not matter. In rare cases, treating for phosphates makes sense. But not using the cheap stuff from pool stores. There is proper chemicals available. Though that is not your issue.
What test kit are you using? Please add that to your signature.
A non-SWCG pool should not have your level of CYA. It makes maintaining your FC in the target level of 9-11 ppm difficult. Up to you.
Your SLAM level FC is 31ppm. Prior to starting your SLAM lower your pH to 7.2. Maintain your 31 ppm FC as often as possible until you pass the three criteria.
Your TA of 70 ppm was fine. By adding baking soda you have now raised it so your pH will rise quicker and you will be adding acid to lower your pH and thus your TA.

Thanks! So do you recommend I drain some of the pool and refill before SLAMing to lower my CYA?
My pool test kit is a drip kit that only lets me check FC and PH accurately so the results I shared are from pool store. (I know, I know...I just order the Taylor Tech K-2006 kit, should be here by 5/29.)
Will it hurt my pool hardware to have FC at 31PPM?
Last question, how much do you recommend I drain before refilling?

 

[Flying Tivo]

If water is cheap, drain at least 60% of your pool. That will get you a CYA around 30 which will make the SLAM level of FC a lot easier and inexpensive, but wait for the test kit so you can test more accurately the CYA levels.

 

[mknauss]

Follow what Felipe said.

A FC of 31 ppm with a CYA of 80 is fine. But you need your own test kit to verify the data. Pool store CYA tests are notoriously wrong.

 

[Krutz]

Thanks! Yall are awesome