HELP with algae/zero chlorine in saltwater pool despite multiple shocks

[IceShadow]

Keep in mind that evaporation and refilling doesn’t lower CYA. You need to pull water from the pool and then refill to do that.

Did you do the diluted CYA test? Full to 7ml mark with pool water, then to 14ml with tap water, shake to mix, squirt down to 7ml in the sink, then do the test as normal with that 7ml sample.

 

[Koko]

Keep in mind that evaporation and refilling doesn’t lower CYA. You need to pull water from the pool and then refill to do that.

Did you do the diluted CYA test? Full to 7ml mark with pool water, then to 14ml with tap water, shake to mix, squirt down to 7ml in the sink, then do the test as normal with that 7ml sample.

We're draining and filling at the same time. I probably didn't do the diluted test right. Can try that again...

 

[Koko]

So I'm reading that saltwater pools can go as high as 80 on the CYA, but the Intellichlor manual says to keep it between 30 and 50. Any thoughts on that?

 

[frustratedpoolmom]

So I'm reading that saltwater pools can go as high as 80 on the CYA, but the Intellichlor manual says to keep it between 30 and 50. Any thoughts on that?

Plenty. Ignore it. lol

 

[Koko]

I realize I'm posting rather sporadically, sorry for that! In addition to the "pool trauma" there's a lot of other stuff going on including a very sick kitty that was at the emergency vet twice this weekend.

So I re-tested FC, CC, and CYA. This time I got:

FC: 8.0
CC: 2.25 (another math issue, my degree is in anthropology )
CYA: 90 or so

So the short period of simultaneous draining and filling did get the CYA down. What's a good number to aim for before trying to address the FC and CC? I'd like to do a SLAM (the instructions for which I will need to review again) but presumably the CYA should come down a little more first? The high FC appears to be controlling the algae for the time being (as in it doesn't look any worse).

Thanks again!!!

 

[mknauss]

Best to get the CYA to 50 ppm or so. That would put your shock level FC at 20ppm.

 

[Koko]

That might take some doing. What if I got it down to 70? I think we'd rather add chlorine (cheap) than find out what metered water costs. They just installed the meter late last fall.

 

[Koko]

I found the chart! So a lot

 

[Koko]

We've had a rough week, the sick kitty didn't make it But we're back to the pool problem now. Today's test results are much better, and the CC levels have dropped quite a bit. The pool is in full sun all day, so I'm thinking that's what did it? So how much liquid chlorine do I need to add at this point to kill off the remaining CC and the tiny bit of algae we are still getting when we brush? And how long until it will come down enough to swim?

FC: 5
CC: 1
PH: 7.8
Alkalinity: 160 ppm
Calcium hardness: 300 ppm
CYA: 70 ppm
Salt: 3150 (per the Easy Touch reader thing)

Thanks!!!

 

[mknauss]

Follow the SLAM Process. Your SLAM FC level is 28 ppm. Lower your pH to 7.2 with muriatic acid and follow the process.

 

[Koko]

Follow the SLAM Process. Your SLAM FC level is 28 ppm. Lower your pH to 7.2 with muriatic acid and follow the process.

Thanks!

 

[Koko]

Since math is not my strong point, and my husband thinks I'm insane, that's almost 5 128oz bottles of liquid chlorine, correct? 28ppm minus the existing 5ppm for 23ppm, then 26 oz = 1ppm increase in a 20,000 gallon pool, so 26 oz X 23 = 590 oz divided by 128 oz per bottle = 4.6 bottles?

 

[mknauss]

That is correct. And you will need to test your FC and raise it back to 28 ppm several times per day with liquid chlorine.

 

[Koko]

Thank you again! I'm in charge of the taxes too which is mildly horrifying

 

[Koko]

How fast will it burn off?

 

[mknauss]

At the start, pretty quick. I would suggest, if you can, to test and add LC every 2-3 hours to start.

 

[Koko]

Thanks! We'll do the SLAM tomorrow!

 

[jblizzle]

Use PoolMath, there is no need for you to do math. Enter pool size. Enter 5 for now. Enter 28 for target. It will tell you how much to add.

 

[Koko]

So we are almost 4 hours into the SLAM. I'll test the water again later and post, but when I checked about an hour ago we were right at 28 for FC, and about 1 (maybe less) for the CC.

In the meantime, is this a good thread to ask about suction issues, or should I start a new thread? Thanks again!!!

 

[jblizzle]

Here is fine. With algae in the water, the filter will clog quickly reducing suction and flow.