Algae

[meow_meow]

Background: have a pool company (sigh, I know, ready to fire them after this week).

Appx 15,000 gallon plaster pool that was just switched to salt (Hayward Tcell940) Thursday. On Friday, I noticed several small spots of algae on the walls. I brushed and called the pool company. They came out and added algaecide. This morning, I notice one small spot of algae on the wall and some on the weir door. Text owner. Said they didn’t need to do anything other than add the algaecide and it might take a couple days. Okay….

I have a Taylor test kit and used it for the second time since owning the pool, so unsure if I trust my measurements - I ran to Leslie’s just in case I’m an idiot.

Help. Can I treat this whilst having my pool company trying to solve it?

FC: 1.8
CC: .4
PH: 8.1
TA: 220
CH: test it twice. Somewhere between 350-450
CYA: <30
Salt: 3200

 

[mknauss]

We recommend you follow the SLAM Process

The pool service company will not do that.

Up to you -- what kit do you have? How old are the reagents? Where has the kit been stored?

 

[meow_meow]

We recommend you follow the SLAM Process

The pool service company will not do that.

Up to you -- what kit do you have? How old are the reagents? Where has the kit been stored?

Taylor 2006c with the added salt kit. The kits were bought last year and stored inside. All the reagents are good until this July-Oct. Salt kit is out of date as of 11-23

 

[mknauss]

OK -- great. Your kit should be good to go.
Do you wish to tackle this? The pool service will likely disrupt your process when they visit.

 

[meow_meow]

OK -- great. Your kit should be good to go.
Do you wish to tackle this? The pool service will likely disrupt your process when they visit.

Well, I guess I don’t know if I should tackle this if they are coming back for their regular service on Wednesday. I do plan of letting them go after this (and I’ve had a few other issues with them additionally). I’m wondering if I shouldn’t let this aspect play out, then take over my pool chemistry.

Thoughts?

 

[mknauss]

They will add a large amount of chlorine (might be dichlor, which would not hurt as your CYA is low) and algaecide. The algaecide is a waste, and will consume chlorine. Up to you.

I have never let anyone other than myself manage the pool water chemistry.

 

[meow_meow]

They will add a large amount of chlorine (might be dichlor, which would not hurt as your CYA is low) and algaecide. The algaecide is a waste, and will consume chlorine. Up to you.

I have never let anyone other than myself manage the pool water chemistry.

Yes. I think I want to take care of it. I have until Wednesday before they come back. And at that point, I’ll probably be letting them go.

From my math and from the order to start:

Lower PH to 7.2 = 71oz of 31.45 Muriatic Acid (which I have from last summer)

Raise my CYA? Unsure here. If I do, raise it from 20 to? If leaving it at 20, SLAM level to 10?

Add bleach (I have Clorox disinfecting). Looks like I’d need about 205oz.

Am I even on the right track?

 

[mknauss]

Add 5 ppm FC worth of liquid chlorine. Not Clorox. It has additives. Walmart has Pool Essentials
Add 10 ppm CYA worth of stabilizer using the sock method.
Lower pH to 7.2 using muriatic acid.

Once you have completed the above, target your FC for 12 ppm. This is the SLAM level for 30 ppm CYA. For now assume that is the level you have.

Test CYA 48 hours after the granules are dissolved from the sock. Add more if the test shows less than 30 ppm.

Follow the SLAM Process

 

[meow_meow]

Add 5 ppm FC worth of liquid chlorine. Not Clorox. It has additives. Walmart has Pool Essentials
Add 10 ppm CYA worth of stabilizer using the sock method.
Lower pH to 7.2 using muriatic acid.

Once you have completed the above, target your FC for 12 ppm. This is the SLAM level for 30 ppm CYA. For now assume that is the level you have.

Test CYA 48 hours after the granules are dissolved from the sock. Add more if the test shows less than 30 ppm.

Follow the SLAM Process

Sorry, but I’ve read the SLAM process and what you’ve said doesn’t make sense to me.

“Add 5 ppm FC” and “add 10 ppm CYA stabilizer” - does that mean I need to figure out how much of each product to get to those levels? Am I able to use liquid CYA stabilizer or does it need to be granular?

 

[mknauss]

The 5 ppm FC is to just get some chlorine in the water quickly.
Use PoolMath for amounts. 5 ppm FC would be 96 ounces of 10% liquid chlorine.
You can use liquid stabilizer, but we recommend the dry granules. 20 ounces of dry stabilizer would add 10 ppm of CYA.

 

[meow_meow]

The 5 ppm FC is to just get some chlorine in the water quickly.
Use PoolMath for amounts. 5 ppm FC would be 96 ounces of 10% liquid chlorine.
You can use liquid stabilizer, but we recommend the dry granules. 20 ounces of dry stabilizer would add 10 ppm of CYA.

Will the first thing I do is lower the PH w/ acid before adding the stabilizer & chlorine? Or can I do those all in the same time period? Should I test the PH after adding acid or should I just assume adding the ~80 ounces of MA (31.45%) will get me down to 7.2?

Also, should I turn off my SWG during this process? If so, can it just be turned off/on from the app on my phone? Any harm to leaving it run? Sorry - brand new to most of this and the SWG especially.

And lastly, as someone who experienced chemical burn as a kid - handling MA scares me a bit - best/safest way to handle it? Should I dilute it by adding it to a bucket first?

 

[mknauss]

Only items to wait between adds is chlorine and acid. 15 minutes with pump running.
Add the acid and test after 15 minutes. Add more if necessary.
We recommend turning SWCG off. You can reduce the % to 0.
Pour acid directly from the jug into the water at a return jet with pump running. Brush the area afterwards. Pour slowly.
Read Chemical Storage and Safety - Further Reading