SLAM'ing by (educated) guesswork.

[NoTan2]

I haven't needed to SLAM the pool for 17 years. Last week we experienced a "significant weather event" and the pool finished up with a belly full of mud.
And it was the day before the Easter break and we were going away for a week. Oh well - just turn it off and deal with it when I get back.

Yes, it was a lovely shade of green.

Didn't bother testing the FC - had to be 0 so just tested the CYA which was around 30 so I added 13l of liquid Cl. (It's labelled as 125g/l which I believe corresponds to 12.5% on the Calculator here but it acts more like 6% so I just leave the calculator to 6%). Should have raised the FC to around 15. Tested it an hour later and it read as 16 so looking good.

However, oops, that was the last of the r-0870. Normally, I like to stay ahead of the game but slipped up this time. Of all the times to run out of reagent!

Hmmm... there's that old bottle of r-0870 which I put aside when I got the new bottle last year. As expected, it had gone pretty hard. Nothing to lose so let's just "scrape" some off and try it. Turned the water a nice pink colour and read as 17. Don't quite know what to think of that. But the new reagents won't arrive for a few days. Time for some creative water treatment.

After 3 hours it had dropped to 12 so added 3l of Cl and it tested back up to 16. All I can do is brush and brush and add a couple of litres every couple of hours and see what happens.

This morning, it's a pleasant shade of cloudy blue so something's going right. FC dropped to 12 overnight. It's a cartridge filter so I'll just clean it once a day. The infloor vents are keeping the floor agitated nicely and saves me the bother of vacuuming at least.

I'll just keep doing this until the new reagents arrive. I'm guessing the water is going to be clear before this happens so I don't know whether to trust my dodgey reagent or just gradually back off the amount of added Cl after it clears. Any suggestions welcome.

Thanks,
Paul.

 

[YippeeSkippy]

Paul, the older reagents seem close enough to keep using until the new shipment arrives. I've heard folks grind it up again using a pestle. If you end up adding a little extra chlorine that won't hurt, but under-dosing will waste time.

Maddie

 

[cfherrman]

I've heard that people use a bit more of the powder when it's old as well

 

[NoTan2]

Paul, the older reagents seem close enough to keep using until the new shipment arrives. I've heard folks grind it up again using a pestle. If you end up adding a little extra chlorine that won't hurt, but under-dosing will waste time.

Maddie

Thanks Maddie,

That's good to know. I've been managing to scrape enough out for testing.

Yes, liquid chlorine is only 90c a litre so I'm not worried out being a bit heavy handed with it.

I'll need to wait for the new reagents to finish off the process as I'm not getting any pink after adding the r0003 and there surely must be some combined chlorine. It's out of date as well.

- - - Updated - - -

I've heard that people use a bit more of the powder when it's old as well

Hi cfherrman,

I'm sure that I read on this site somewhere a discussion about how accurate you need to be with the amount of powder. I believe that it was mentioned that as long as the water turns pink, it's fine.
I've been adding two good heaped spoonfulls. If I can grind some up as per Maddie's suggestion, then I'll try adding some extra powder and see if it makes any difference.

Thanks.

 

[NoTan2]

Just an update.

I've decided to terminate the SLAM on day 14 despite the pool water not being clear. It is showing a very slight improvement each day.

It has passed OCLT at least three nights in a row. I tested FC twice yesterday evening and twice this morning (just to be certain) and, once again, there was zero loss of FC. CC has been 0 since my new reagents arrived 7 days ago.

Given the above and that:-
1. The pool was crystal clear before Easter and was only running on zero FC for abut 4 days. It was only slightly green and nothing like the bright green in the pictures other people post here.
2. I've never had a problem with algae before.
3. I've kept the FC at or above 16 (CYA is 40) for 14 days with the filter running 24/7 and the infloor running about 10 hours each day.
4. The pool consumed a huge amount of silty mud just before Easter.

I'm convinced that what I'm seeing in the pool is now fine mud and not algae. I don't understand why the filter hasn't cleared the sediment out after 14 days of filtering - I'm cleaning the filter every few days despite no rise in filter pressure. The filter cartridges are relatively new.

So I'm going to let the FC drift back to about 8 and then turn the chlorinator (SWG to the folks in the US) back on and just run the pump for 8 hours overnight, let the sediment settle during the day and vacuum it in the afternoons.

I'm prepared to be proven wrong.

 

[YippeeSkippy]

Well, keep us posted on the outcome, ok?

Maddie

 

[NoTan2]

Well, keep us posted on the outcome, ok?

Maddie

I will, Maddie.

I'm not going to touch the pool for the time being. Our local weather forecasters are talking about the "possibility" of an east coast low forming next week. If that happens the pool is going to get dirty again and I'll likely need to keep draining water out as it fills up. Any attempts at getting it balanced before then may well be wasted. Looks like summer is pretty much finished so we won't be doing much swimming.

 

[NoTan2]

Update:
I was about to report that the pool had cleared up (eventually) but a closer inspection revealed that most of the dirt had just settled to the bottom.
I'm convinced that this is a result of poor circulation caused by a re-plumbing exercise a year or so ago so I'll start a new thread in the appropriate sub-forum and hopefully get some advice on this.

Thanks,
Paul.