First Taylor Test - High CYA

[MarkVT]

Hi Everyone. I’ve been struggling to get my pool water clear and my free chlorine levels up since we opened a few weeks back (this is a new house and a new pool to us, our first pool too). I’ve had two trips to the pool store to test the water, and after a ton of money and chemicals with no results I’ve gotten my own Taylor kit and started testing today. First thing I tested was the PH and CYA. PH is definitely low, but the CYA comes back at around 80. From what I’ve read this is usually caused by too much stabilizer, which is incredibly frustrating since the pool store had us add stabilizer when we first brought our water in for testing.

From what I’ve read I need to drain some of the pool and replace the water. Before I kick this off I just wanted to confirm thats the right path. I think the pool is about 30,000-35,000 gallons (20x40 pool, 3 feet at the shallow, 12 feet at the deep, but the deep is not constant, it tapers in from all sides).

Any advice is welcome. Thanks in advance!

 

[splashpad]

Hi Everyone. I’ve been struggling to get my pool water clear and my free chlorine levels up since we opened a few weeks back (this is a new house and a new pool to us, our first pool too). I’ve had two trips to the pool store to test the water, and after a ton of money and chemicals with no results I’ve gotten my own Taylor kit and started testing today. First thing I tested was the PH and CYA. PH is definitely low, but the CYA comes back at around 80. From what I’ve read this is usually caused by too much stabilizer, which is incredibly frustrating since the pool store had us add stabilizer when we first brought our water in for testing.

From what I’ve read I need to drain some of the pool and replace the water. Before I kick this off I just wanted to confirm thats the right path. I think the pool is about 30,000-35,000 gallons (20x40 pool, 3 feet at the shallow, 12 feet at the deep, but the deep is not constant, it tapers in from all sides).

Any advice is welcome. Thanks in advance!

Welcome to a more reasonable, afforable and understandable way of pool care!

Can you rerun the CYA test with Step 8 dilutions instructions? Let's make sure it's 80 and not higher

 

[MarkVT]

Hi splashpad, thanks for the quick reply! I have redone the test using the dilution method and it came back at 70 (~35x2). So at least its not higher then 80... I'm assuming some variance is expected with those higher numbers? I probably was not as precise the first time around.

 

[splashpad]

Hi splashpad, thanks for the quick reply! I have redone the test using the dilution method and it came back at 70 (~35x2). So at least its not higher then 80... I'm assuming some variance is expected with those higher numbers? I probably was not as precise the first time around.

There is no 35, so you were spot on with the 80! Well done!

Using the FC/CYA Levels, you'll have to decide if you want manage manual FC levels with high CYA, or do a partial drain, to lower the FC requirement

 

[MarkVT]

Thanks splashpad! I'll go with a partial drain. Feels like this is not something I want to keep wasting money on chlorine for if I can avoid it.

Am I correct in assuming I should empty and dilute to get the CYA levels down before I worry about anything else? This will change the PH anyway so no point in trying to improve that until the drain is done?

 

[splashpad]

Thanks splashpad! I'll go with a partial drain. Feels like this is not something I want to keep wasting money on chlorine for if I can avoid it.

Am I correct in assuming I should empty and dilute to get the CYA levels down before I worry about anything else? This will change the PH anyway so no point in trying to improve that until the drain is done?

Can you add your pool, equipment and test kit details to your signature please?
Depending on your pool surface & local water table, you will need to take care with not draining to far (unless you've drained successfully before w/no issues)

Otherwise, correct!

 

[IceShadow]

A 50% exchange should take you down to 40ppm CYA, which is a good place. But like splashpad said - fill out your signature and we can give advice on the best way to exchange water.

 

[MarkVT]

Thanks Guys! I have updated my signature with my pool details.

For draining, I have valves for each skimmer, and the main drain. I assume I can just close the valves for the skimmers and use the main drain to drop the water levels? Is it better to vent as waste water, or should I take this opportunity to backwash and really flush out the filter? Or is there a chance of losing sand while backwashing that I don't want to do?

Also, thanks again for everyone being so active on this and willing to answer questions that I'm sure have been asked in different ways many times before.

 

[MarkVT]

I should note, that the local water table is very close to my pool level. Is there a concern that if I drain too far there can be issues with pressures from outside the pool pushing in? Or is that not a thing?

 

[splashpad]

So with vinyl, you want to leave 12" in the shallow end, otherwise you risk your liner shifting.

You can use the main drain, but we much prefer a sump pump (hardware store $50-80) or rental $30-50, vs risking the pool pump, which could cost hundreds-thousands to replace!

 

[splashpad]

I should note, that the local water table is very close to my pool level. Is there a concern that if I drain too far there can be issues with pressures from outside the pool pushing in? Or is that not a thing?

It's VERY much a thing. A water exchange would be much safer
Details for appropriate method of exchange: Draining - Further Reading

 

[MarkVT]

Hi Everyone!

So I successfully exchanged a good chunk of the pool water over the last few days. My CYA reading has gone from ~80 down to 60 which I think I can live with for now.

I ran a few of the other tests:

CYA: 60
FC: 0
PH: 6.8? (I guess, the color was a lighter yellow then the chart, so I assume its just very low?)
TA: 60
CH: 220


Is there a wiki or a post somewhere that walks through the order I should adjust things in? ie. address PH first then chlorine levels or get the vice versa? Thanks in advance!

 

[splashpad]

So I successfully exchanged a good chunk of the pool water over the last few days. My CYA reading has gone from ~80 down to 60 which I think I can live with for now.
CYA: 60
FC: 0

Here is the FC/CYA Levels

PH: 6.8? (I guess, the color was a lighter yellow then the chart, so I assume its just very low?)
TA: 60
CH: 220

You have vinyl, you need to get your PH up. Aeration and/or Borax would be good
Try not to use cal-hypo as vinyl doesn't need calcium and your level is fine.

Is there a wiki or a post somewhere that walks through the order I should adjust things in? ie. address PH first then chlorine levels or get the vice versa? Thanks in advance!

See links in my sig

 

[IceShadow]

What Splashpad said! If anything is unclear let us know. Basically keep your pH in line and get your FC either up to the maintenance range on the FC/CYA chart, or get the SLAM Process started depending on how the water looks. How is the water looking now, after the exchange?

 

[MarkVT]

Thanks Everyone. So I decided to exchange the water for another day to try and bring the CYA down a little further. It now appears to be somewhere between 30 and 40. I've added some Borax/(some other left over PH increaser) to bring up the PH Levels which were still pretty low. And once the sun starts to set today I'll kick off the SLAM and see what happens.

The water looks pretty beautiful right now, so hopefully if I can get the chlorine up tonight and stable tomorrow then I guess we will be good to go!