Impact of Winter Rains & Chem Level Reset...advice needed

[VTSoundman]

Some interesting results from winter rains...and looking for some advice with our chem levels.

Since we do not have an automatic overflow drainage system, we have to use a pump. I lost count around 18 instances of pumping - but I estimate to be 18-22 instances. Each time the water level is dropped ~2.5-3" - that suggests we've had 50-60" of rain since December. Note: we're in San Rafael CA, a Mediterranean-like climate. Closing a pool is little more than adjusting pump run times and leaving the cover on.

(Interestingly enough, this far exceed the 'official rain totals' for our area - and there is NO water draining into the pool. There is very small tree overlap, but should not be enough for a 2x rain total difference.)

What is really interesting how CYA levels dropped so much...and how the rain amounts don't seem to correlate to the CYA drop.

Same thing happened for last year opening, but it was quite a bit more dramatic - we went from ~100 to 0. Pool guy thought we were nuts to be excited about 0 CYA. (We've been battling CYA problems for a couple of years. Two seasons ago, it took a ~55% swap + winter rains to get it from off the charts to ~150.)

Anyhow, the day we closed the pool last season: our numbers were:
8 FC
PH 7.3
Calcium 300
CYA <40
Total Alkalinity 90
Borates ~50

(We added ~1.5 gallons of acid over the winter to control PH levels)

Just 'opened' the pool last week (cleaned it), and the numbers were:
0 FC
PH >8.5
CH 370
CYA <10
Total Alkalinity 70
Borates ~25
Water was a little cloudy from algae.

Dumped in 3 gallons of 12% Chlorine, added ~3 qts of acid
Water temps are in the 50's

Yesterday's Tests:
6 FC
0 CC
PH 7.5
TA 70

We are waiting for FC of 1-2 and then will be dumping in 2# of Ascorbic acid for stains...and will re-balance pool chemistry in a week or so.

Seeking Comments on my goal levels:
TA: 80 (leave TA a little on the low side since CH is a little on the high side)
Borates : 40
CYA: 40
The rest will follow TFP guidelines...

Filtering stats:
Winter: Ran our slightly undersized filter 2.5hrs per night, Pressure side cleaner died last summer
Summer: Will Ramp filter runtime to 8hrs
Cleaner will run 1-1.5hrs nightly, depending on debris load.

Any thoughts on the ideal chem levels?
We've had issues with PH climbing quickly/hard to stabilize...any thoughts on why our PH climbs high/so fast?

 

[Texas Splash]

Okay VT, let's get your thread energized. Chemical management starts with the TFP Pool School and Pool School - Recommended Levels page. The most common thing is CYA being too high, but that's obviously not a problem for you this year.

Some might be curious to know what your stains are from or how they got to the point where you need an AA treatment, but if you're committed to that project I guess we can address that later. Once the treatment is completed, it would be best to post a new set of test results. But in short you'll need to increase CYA it a bit - at least to 30 ppm. The target FC would be 4 based on that CYA, but keeping it in the 4-6 range is ideal. Never let it get below 2. Your CH is not bad at all, but certainly keep pH and TA within the recommended levels ranges and you'll be fine. If rising pH continues to be a problem, lower pH a little more than normal (i.e 7.2) which will also bring the TA lower, then simply aerate or allow the pH to rise on its own, thereby leaving the TA lower. A lower TA will help keep the pH down a bit better.

That's a start, although you may have more questions later and/or some of us may toss a question or two back at you. It's how we work here. Hope this helps, and enjoy your weekend.

 

[pooldv]

Sometimes CYA "disappears" over winter with a perfect storm of low to no FC and water temp. It happens often enough.

Feel free to let your TA drop to 70 or even 60 to help stabilize your PH and/or help keep your CSI slightly negative, -0.1 to -0.2. Also, running water features, bubblers, waterfalls or other things that aerate the water will cause PH to rise. Reducing that run time will reduce PH rise.

 

[VTSoundman]

Sometimes CYA "disappears" over winter with a perfect storm of low to no FC and water temp. It happens often enough.

Feel free to let your TA drop to 70 or even 60 to help stabilize your PH and/or help keep your CSI slightly negative, -0.1 to -0.2. Also, running water features, bubblers, waterfalls or other things that aerate the water will cause PH to rise. Reducing that run time will reduce PH rise.

Hi Pooldv - never run any blubbers or fountains - don't have any. The Krauly lengend broke half-way throught last season (will be replaced with one once the AA treatment has been completed.) The only aeration would come from swimming activities for my wife and I.

I'll try letting the TA drop a bit more once the AA treatment is done to see if we can't get the PH to stabilize. Thx for the tip. Last summer season, we went through 8 gallons of acid. Usage is quite light (lighter than I would like, but sometimes that is they way it is).

 

[VTSoundman]

Okay VT, let's get your thread energized. Chemical management starts with the TFP Pool School and Pool School - Recommended Levels page. The most common thing is CYA being too high, but that's obviously not a problem for you this year.

Some might be curious to know what your stains are from or how they got to the point where you need an AA treatment, but if you're committed to that project I guess we can address that later. Once the treatment is completed, it would be best to post a new set of test results. But in short you'll need to increase CYA it a bit - at least to 30 ppm. The target FC would be 4 based on that CYA, but keeping it in the 4-6 range is ideal. Never let it get below 2. Your CH is not bad at all, but certainly keep pH and TA within the recommended levels ranges and you'll be fine. If rising pH continues to be a problem, lower pH a little more than normal (i.e 7.2) which will also bring the TA lower, then simply aerate or allow the pH to rise on its own, thereby leaving the TA lower. A lower TA will help keep the pH down a bit better.

That's a start, although you may have more questions later and/or some of us may toss a question or two back at you. It's how we work here. Hope this helps, and enjoy your weekend.

Hi Texas...thx for the quick response. I'm into my 2nd week of AA treatment. FC has dropped to 0-1. No Algae as of yet (no polyquat). I think the water is too cold to get any growth as of yet. During the treatment, PH dropped to 6.8. I had some PH UP laying around, so I dropped some in. PH is back up to 7.2. I will be applying 2nd cource AA treatment as I did get some improvement. I posted a question regarding sequestrants/cheleating solution to the chem 201 forum.

AA treatment was suggested after using a sock filled with AA - I held it against some of the stains and they went away. Extensive staining is present from neglect of previous owner. I believe a failed heater combined with failing galv water piping used to re-fill the pool caused the metal staining. I have copper intake/return piping, but the copper test always comes back negative.

 

[Texas Splash]

Yes, I recall seeing that other thread. Hopefully Swampwoman will key-in on that one. She's got a tremendous amount of knowledge in that area. Because you are managing multiple issues simultaneously (AA treatment, low FC, sequestrants, pH, etc) stay in close contact with us, or perhaps even shoot SwampWoman a PM directly if you don't see a reply soon. I know you have to watch FC levels closely while you undergo specific treatments, but you don't want algae either. Otherwise it's back to the beginning with a SLAM, and we don't want that. Best of luck. I'll watch your threads as they develop.