Liner company recommendations vs TFP

[fisherman]

Hello, just uncovered and started the processes of cleaning up the pool after a brutal winter. The winter was spent learning here. We are a new homeowner as of September 2013 with an old but nice in ground pool. The previous owner had a new liner put in may 2013 obviously with a total fill. The prior owner just ran the pump 24/7 with the SWG set at about 60%. The water was crystal clear so for the few weeks we could use the pool I did not mess with it.
I tested our water today with my new Taylor 2006 kit.
Results
CL 0
CC 0
Ph 7.0
CYA 0
Total Alk - 80
Calcium hardness 80

Clearly I need some CYA in this pool and once it warms we will add the correct amount. We did start filtering today with the pump running. The liner paperwork I have says to avoid low ph as this can wrinkle the liner. I added baking soda and now the Ph is in the 7.4-7.6 range. Total alkalinity bumped to 90.

The liner warranty suggests a total alkalinity of 100-150 TFP suggests with a SWG for a vinyl pool 60-80?

What is the best path? If I do not want to increase TA anymore when my Ph dips down then either Borax or sodium carbonate would be better options if I understand everything correctly

Thanks !

 

[Isaac-1]

The TFP TA suggestion for an SWG is due to a side effect of running an SWG which tend to effect pH drift (creation of hydrogen ions I think) therefore the lower suggested TA when running an SWG. Running at the higher TA and you will constantly have to be adjusting pH.

Ike

p.s. lack of CYA in the pool will make the chlorine act harsher on the liner and potentially cause it to fade prematurely, also the CYA sample should be tested at swim temperature, so let it warm up indoors if needed.

 

[pwrstrk]

I'm assuming your water temp is still too cold for your SWG, so you need to get some chlorine in the water. I would add enough bleach to get you to an FC of 2-3 ppm.
After that get enough stabilizer to a level of 30-40 ppm. After that's all dissolved adjust your FC for the CYA level. It will take up to a week for the CYA to fully register on a test so just assume it's there.
When you ready to start your SWG adjust your CYA level up slowly for it.
I wouldn't do anything to your PH right now as PH usually rises on its own. When your SWG is running they have a tendency to increase PH.

 

[Patrick_B]

Welcome to the forum Fisherman!

We suggest the lower TA for a SWG for reason Ike pointed out. A vinyl liner is very tolerant of broad ranges of hardness and TA, so no worries about hurting it.

As for the pH adjustment, you are correct in what to use but either of those will still increase alkalinity. Not that it's a problem, you just can't change one without effecting the other. Sodium carbonate (Soda Ash or Washing Soda) is ok, but we usually suggest Borax because it is sometimes easier to find, and it has side benefits as well. Soda Ash is usually pretty easy to find at hardware and pool stores.

Just don't use Baking Soda (Sodium Bi-Carbonate) to raise pH. Sounds like you have a handle on that, but people often make that mistake.

Do address the Cya and FC levels now, before you get into trouble with Algae.

 

[fisherman]

Thank you all for your answers. This very much confirms what I have learned. I am off to the store today to get stabilizer of which pool math tells me I need about 120oz for a starting target of 40. I did let the sample warm and repeated it twice. Based on my conversations with the previous owner, zero does make sense too. I did also get my FC up to 5 yesterday with bleach and will maintain a 3ish range while the pool is idle until fully opened and will slam if testing results require.

The other recommendation from the liner paperwork suggests to use Sodium Bisulfate instead of muriatic acid if lowering PH is required. The paperwork says that muriatic acid may affect the print pattern and eventually it can start to come off. This one does not make that much sense as in water acid is acid and both hydrochloric acid and sulferic acid (dissolution product of bisulfate) are both very strong acids.

Any insight here would also be appreciated

 

[jblizzle]

Muriatic acid is fine. Just pour slowly in front of a return jet in the deep end if you have one. Then a quick brushing as insurance.