SLAMing a SWG pool

[surfbabe]

My new neighbours have inherited a SWG and have not much idea of how to manage things. I have converted my own pool over to BBB thanks to you guys and have no problems at all. Anyway, they have gladly taken me up on my offer of help since their pool is turquoise right now..

I took these measurements just now:

15000 gallon pool
FC 0
CC ?0.5 (turned slightly pinkish and then cleared after one drop)
CH 775
pH 8.2 +
TA 60
CYA 0

Their strip test showed salt at 3500

Obviously their water needs to be SLAMed - but where to start?

I've given them muriatic acid and told them to add 32oz to start bringing down pH -

What next? should I add CYA, how much for a SLAM? Obviously I don't know how much 8.25% bleach to add based on 0 CYA.

thanks for your help.

Karen

 

[JoyfulNoise]

I doubt the water has 0 CYA unless it is a fresh refill. Has the pool been refilled recently?

If not, a low CYA pool should be brought up to a level of 30ppm CYA and then SLAM'd with bleach (leave the SWG off, it won't do anything useful at this point).

You need to confirm that the CYA is indeed low before you go adding more.

 

[surfbabe]

I used the CYA test in the TF100 kit. I poured the solution into the narrow tube with the black dot and it was absolutely clear right up to the top - I could still see the black dot perfectly. The solutions are fine - I used them yesterday in my pool with no problems....
Is there another way to confirm the CYA? Wouldn't this result match the FC level at 0 - their chlorine is just being used up here in sunny Austin and they obviously have algae

 

[surfbabe]

They have a Jandy SWG - I just switch it to "off"?

Sorry for the very basic questions but they are Italian, don't know or understand what they've got and it's not my system!

 

[JoyfulNoise]

It's hard to say for sure what is going on since we have no history on their water care but it is the case that any CYA level less than 20ppm will look clear. Low CYA and visible algae will definitely crash the FC.

So just be cautious in raising the CYA. You want to target a CYA of 30ppm for the SLAM so that you can use an economical amount of bleach and still get protection from the sun.

 

[jblizzle]

Since the CYA and FC appear to be zero, I would check if there is a high demand like from ammonia before adding any CYA.

Add 10ppm of FC and retest after 10 minutes or so and see what the FC level is. If the FC drops a lot, keep doing that until the FC holds at 10ppm. Then get the CYA up to 30ppm and follow the SLAM.

 

[cowboycasey]

^^^^^Jason said exactly what I was going to say^^^^^

If no CYA only bring it up to 30 once it starts holding chlorine, after the SLAM and you pass all 3 steps bring your CYA up to 70 and fire up the SWG

 

[surfbabe]

Just wanting to check something....

the pH "reading " in the cells was deep pink - much deeper pink than the 8.2 reading. Again, I know the kit is OK since it reads my pool water just fine. I assumed since it was a really deep pink that the pH was well over 8.2. However after adding muriatic acid (32oz I think), it is still showing as deep pink. Which is surprising considering 15000 gallons. Do we just keep adding muriatic acid (in smaller amounts) until it gets to 7.5? Or am I missing something with this swg pool?

 

[JoyfulNoise]

Just wanting to check something....

the pH "reading " in the cells was deep pink - much deeper pink than the 8.2 reading. Again, I know the kit is OK since it reads my pool water just fine.

This statement is confusing. What do you mean? What is the pH of your pool water?

 

[surfbabe]

I'm testing my neighbour's swg pool which shows as deep pink.

MY pool is a different one and the pH of that is 7.5 as shown by the test kit. I'm using my pool as the "control" to make sure the kit is ok.

 

[ping]

Just wanting to check something....

the pH "reading " in the cells was deep pink - much deeper pink than the 8.2 reading. Again, I know the kit is OK since it reads my pool water just fine. I assumed since it was a really deep pink that the pH was well over 8.2. However after adding muriatic acid (32oz I think), it is still showing as deep pink. Which is surprising considering 15000 gallons. Do we just keep adding muriatic acid (in smaller amounts) until it gets to 7.5? Or am I missing something with this swg pool?

Is the FC still below 10ppm? If it is, then the pH is still high and the water needs more acid. You can add acid and let it mix for 30 minutes and test the pH again.

There is nothing special about salt water pools that cause the tests to perform differently than any other chlorine pool.

 

[JoyfulNoise]

If the pH test is pink, then the pool you are testing is probably a lot higher than 8.2. SWG pools almost always have rising pH. It sounds like your neighbor has no clue how to manage a pool and has let the pH get out of control. That's not a dig at them, they just don't understand how it all works. So you will have your work cut out for you in helping them. They should, if you can convince them, learn to use TFP so they can ask questions directly. This type of indirect support makes managing their pool difficult.

In the short term, the pH needs to be lowered or else the salt cell will scale up with calcium. Keep adding MA in consistent batches while retesting in between until the pH starts to drop.

 

[surfbabe]

Thanks. You are right, they don't have a clue. I will encourage them to come here themselves. They are Italian and whilst spoken English is OK and reading comprehension is good, I'm not sure they are up to writing and asking for help. I am sympathetic since I was in a similar situation in France. Good neighbours were a godsend. My plan for them is to get rid of the algae and set up their pool chemistry according to your SWG guidelines ( which I've printed out and put on their refrigerator). Then get them to learn to test and adjust chemistry.

 

[Richard320]

Just wanting to check something....

the pH "reading " in the cells was deep pink - much deeper pink than the 8.2 reading. Again, I know the kit is OK since it reads my pool water just fine. I assumed since it was a really deep pink that the pH was well over 8.2. However after adding muriatic acid (32oz I think), it is still showing as deep pink. Which is surprising considering 15000 gallons. Do we just keep adding muriatic acid (in smaller amounts) until it gets to 7.5? Or am I missing something with this swg pool?

Yes.

Anything over 8.2 will read as 8.2. You could be at 8.8. Also remember that pH is logarithmic. The jump from 6 to 7 is a factor of ten. The jump from 6 to 8 is 100! So just keep plugging in 8.2 as now and dose it to get to 7.2, let it mix (brushing speeds that up) and recheck the pH. When it finally shifts down to something other than 8.2, use that as your new current number and get it to 7.2.

Then try the chlorine demand/ammonia test as described above. Then maybe add some CYA to get to 30 and start the real SLAM. You don;t need to wait for the CA to dissolve or register. Once the sock is in the pool, consider it there and use that CYA value to set the shock level (psst- it's 12 FC for 30 CYA) and it's jugs away.

Tip: If the neighbor hasn't ordered his own test kit, when he does, tack on some extra FAS-DPD reagents to replace the stuff you'll be burning through.

 

[cowboycasey]

You are awesome, I have been to many other countries and it is SO NICE when local people help when there is a problem.. It is very hard when your foreign and you kind of understand and speak the language but it is very hard to do it over the internet

I bet if you helped them set up a username and introduced them on the site that would help them out very much, we are always willing to help anyone, and if all else fails have them write in Italian we can translate pretty easily

Google

Si sono impressionanti , io sono stato in molti altri paesi, ed è così bello quando la gente locale aiutano quando c'è un problema .. E 'molto difficile quando la tua estera e può tipo di capire e parlare la lingua , ma è molto difficile da fare esso su internet

Scommetto che se hai aiutato li impostare un nome utente e li hanno introdotto sul sito che li avrebbe aiutati fuori molto , siamo sempre disposti ad aiutare chiunque , e se tutto il resto fallisce li hanno scrivere in italiano possiamo tradurre abbastanza facilmente

The translate feature is not always perfect but it is close enough to understand what you need

 

[surfbabe]

so, I sent my neighbour to the pool store to buy stabiliser.....

they sold him this. Natural Chemistry 07401 Instant Conditioner- 1 Gal

Is this OK?

 

[JoyfulNoise]

Liquid conditioner is only 30% available CYA. So it depends on how much is needed. Granular CYA is 100% CYA so it's a better bang for your buck but it's a little more involved to add granular (sock method, slow dissolve). So if all you need is a little bump in CYA, liquid will work fine it's just the most expensive option.

 

[Texas Splash]

Yes, it will work. Probably much more expensive than the granule stuff, but it will work.

 

[surfbabe]

I think I will teach him a new English verb..... to be poolstored!!

I wrote down "CYA stabiliser either liquid or powder - smallest amount"

We live close to the store so I'll get him to exchange it - it will be good for his English practice!

 

[pabeader]

One thing that needs to be stressed here is before you/they put in the CYA you need to verify that you/they are not fighting an ammonia battle. If you are, the bug that ate the CYA might still be in there, waiting to eat more.