Can't lower ph

[anzura]

I'm new here and having the same issue. My pool is only a few months old and my ph is out of control. When I took over the maintenance from the pool company, I had to put in 15 drops of the demand to get it to the correct ph, I'm now sitting at 6 drops. I'm adding 16oz of MA every other day. I guess I should be adding more often? My TA is 100, so I'm good there. I have a solar cover on right now trying to get the temp up, I suppose I have to keep it off until I get this ph problem resolved. Because it's a brand new pool, any ideas on how often I will have to add acid? I hate to keep the solar cover off all spring. I have the TF 100 ordered.
Debi
I don't have a signature line yet, but here's my pool info.
19,000 gal, PebbleTec, salt water.

 

[ajw22]

Get your TF-100, post your test results, and we will help you tackle your pH. Your TA at 100 is high and contributing to rising pH.

Unfortunately rising pH is one of the byproducts of plaster curing. Plaster can take a year or more to fully cure.

There are other factors that cause pH to rise in a pool. Aeration from spa spillovers and water features is one. High pH or TA in your fill water is another. So when you get your TF-100 test and post the pH, TA & CH of your fill water.

Basic process for lowering pH is if it tests above 8 use PoolMath and say pH is 8 and target is 7.6. Add the amount of MA PoolMath says. Test pH and TA in an hour and repeat the process until your pH is into the 7s. Keep your pump running.

In the meantime I suggest you review ABCs of Pool Water Chemistry and Pool School - Trouble Free Pool

 

[anzura]

Get your TF-100, post your test results, and we will help you tackle your pH. Your TA at 100 is high and contributing to rising pH.

Unfortunately rising pH is one of the byproducts of plaster curing. Plaster can take a year or more to fully cure.

There are other factors that cause pH to rise in a pool. Areation from spa spillovers and water features is one. High pH or TA in your fill water is another. So when you get your TF-100 test and post the pH, TA & CH of your fill water.

In the meantime I suggest you review ABCs of Pool Water Chemistry and Pool School - Trouble Free Pool

Thanks! I have read all the required reading material. I will for sure test my fill water when my TF 100 arrives.
Is there a thread that talks about the different MA? I've been getting mine at Home Depot. They sell 2 different kinds and I can't figure out what is different about them. It doesn't say on the boxes.

 

[mknauss]

I suspect your HD has two strengths of MA in the pool chemical section. One is 14.5% and one is 31.45%. Both are about the same price.

Economically, the 31.45% is best. Do realize it has irritating fumes and care needs to be used when pouring it in your pool. The 14.5% has less fumes.

The % is listed on the box. Fine print.

 

[ajw22]

Is there a thread that talks about the different MA? I've been getting mine at Home Depot. They sell 2 different kinds and I can't figure out what is different about them. It doesn't say on the boxes.

HDX 1 Gal. Muriatic Acid (2-Pack) pH Adjuster 10031HDX - The Home Depot

HDX 1 Gal. Muriatic Acid (2-Pack) is a powerful pH reducer for your swimming pool. It comes ready to use, with no pre-mixing required. This fast-working chemical helps prevent scaling caused by calcium-based

www.homedepot.com

Box says it is full strength 31%

Recommended Pool Chemicals

Which should I buy? TFP's recommended pool chemicals are cheap, easy, and won't unbalance your pool water.

www.troublefreepool.com

pH – Acidity/Alkalinity
Lowering pH

To lower pH you can use either muriatic acid or dry acid. Muriatic acid is less expensive, though it can be annoying to handle. It is best to use muriatic acid if you have a SWG. If you don’t have a SWG, and handling muriatic acid bothers you, you can use dry acid.

Muriatic acid is sold by most hardware stores and some paint stores. The big box hardware stores, like Home Depot and Lowes, almost always have it, but they seem to put it in different departments from store to store. Sometimes it is outside in the garden department, sometimes in pool supplies, and sometimes in the paint department.

Muriatic acid is available in various strengths. The most common strength is called either 20° baume or 31.45%. 10° baume or 15.725% is easier to handle but you need twice as much and it is usually more expensive.

You should always wear eye protection when handling muriatic acid. You do not want to breathe muriatic acid fumes. If you spill any on your clothes it will cause damage. Muriatic acid may sting a bit if you get it on your skin, but won’t normally cause any serious harm as long as you rinse it off right away.

Muriatic acid should be added to the pool by pouring slowly in front of a return jet with the pump running. You should pour slowly enough that pouring an entire jug takes more than two minutes. Leave the pump running for at least 30 minutes after adding muriatic acid.

Dry acid is sold by pool stores and the pool departments of some big box stores. Dry acid is sold under various names, including PH Down, PH Reducer, PH Decreaser, Lo-n-Slo, etc. Dry acid is best added by pre-dissolving it in a bucket of water and then pouring that slowly in front of a return.

 

[anzura]

I suspect your HD has two strengths of MA in the pool chemical section. One is 14.5% and one is 31.45%. Both are about the same price.

Economically, the 31.45% is best. Do realize it has irritating fumes and care needs to be used when pouring it in your pool. The 14.5% has less fumes.

The % is listed on the box. Fine print.

Just went and checked the box. It is indeed 14.5% I don't know why I didn't see this before ? thanks for your help.

 

[iflyjetzzz]

The only MA in my local HD is 14.5%. In order to get 31.45%, I have to buy it at Lowes in the masonry cleaning section, as the local Lowes also only carry 14.5% pool MA.

Anzura, you have the same problem as me... a pool that consumes a LOT of MA. I also have a new gunite pool with a SWG. Note that both a new (concrete/gunite) pool and a SWG increase a pool's demand for MA.
Our pools are almost identical on the specs - 19K gal, SWG, Pebble Tec vs Pebble Sheen.

After waiting the month for my pool to initially cure, I fired up the SWG and was using ~1 gallon of 31.5% MA per week for several months. I am now using ~1/2 gallon of 31.45% MA every week.

My pool is also covered most of the time (light brown autocover) so I'm not consuming a bunch of chlorine during the day so I don't need to run the SWG too much. Again, the SWG increases pH so you need to keep that in mind.

If you keep the cover on your pool, that will actually help keep your pH lower because your pool won't be able to outgas as much CO2 (CO2 lowers pH). If it's not clear, it may also keep your pool from consuming a lot of chlorine.

You should probably post your complete water chemistry numbers so that people smarter than me can make specific recommendations to you.
As a comparison, here are my numbers from yesterday:
TC: 4
FC: 3
pH: 7.5
TA: 70
CH: 340
CYA: 55 (this is considered low for a SWG pool but since I have a cover, I'm OK with it being low)
Borates: 40
Salt level: 3500
Temperature: 72F
This gives me a CSI of -.47 but since the pH rises so quickly and the water is warming, the CSI will move close to zero by the time I add more MA.

If you haven't added borates to your pool, you may want to consider that. My understanding is that it helps stabilize the pH. It also makes the pool water look awesomely sparkly. I bought boric acid over the internet from dudadiesel.com, based on lowest priced/another TFP user's recommendation. You can also use 20 mule team borax.
Full disclosure on borates - if you have a pet that drinks a lot of pool water, you may want to be careful. Borates and Pets

Your TA sounds high for a SWG pool. 60-80 should be your target TA. Adding more MA will help lower your TA.

But the bottom line is that your pool will consume additional MA until the pool is fully cured which can take up to a year. And you will always use more MA than non-SWG pools due to having a SWG.

 

[mknauss]

That is interesting that HD in Las Vegas does not carry the 31.45%. I get mine at the HD in Bullhead City, AZ. They have both strengths in the same cubby in the garden section.

 

[iflyjetzzz]

I've looked into this a bit - apparently local laws/regulations can limit MA strength.

I even looked in the other sections of HD for full strength MA and can't find any. The pool chain here is Leslies and they also do not sell full strength for consumer use - only 14.5%.

 

[mknauss]

A road trip down here to Laughlin might be worth it to buy the full strength! And you can enjoy the river/lake while you are here!

Take care.

 

[iflyjetzzz]

Trying to not veer too far off topic, but it wouldn't be worth it unless I bought a ton of MA and the price was significantly lower than $9.98/gal since that's what I'm paying for Crown 31.45% MA at Lowes. So the river/lake would have to be the big draw for me.

 

[mknauss]

Ha! Probably true! I pay $11.98 for 2 gallons of 31.45% at HD in BHC.

 

[iflyjetzzz]

Ha! Probably true! I pay $11.98 for 2 gallons of 31.45% at HD in BHC.

Wow! That's a lot cheaper than here.

 

[anzura]

The only MA in my local HD is 14.5%. In order to get 31.45%, I have to buy it at Lowes in the masonry cleaning section, as the local Lowes also only carry 14.5% pool MA.

I picked up 2 gallons of the 31% yesterday at Home Depot for $12

Anzura, you have the same problem as me... a pool that consumes a LOT of MA. I also have a new gunite pool with a SWG. Note that both a new (concrete/gunite) pool and a SWG increase a pool's demand for MA.
Our pools are almost identical on the specs - 19K gal, SWG, Pebble Tec vs Pebble Sheen.
After waiting the month for my pool to initially cure, I fired up the SWG and was using ~1 gallon of 31.5% MA per week for several months. I am now using ~1/2 gallon of 31.45% MA every week.
My pool is also covered most of the time (light brown autocover) so I'm not consuming a bunch of chlorine during the day so I don't need to run the SWG too much. Again, the SWG increases pH so you need to keep that in mind.
If you keep the cover on your pool, that will actually help keep your pH lower because your pool won't be able to outgas as much CO2 (CO2 lowers pH). If it's not clear, it may also keep your pool from consuming a lot of chlorine.

I'm very happy to report that as of today my pH was reading 7.5!! I think I've just been very conservative pouring it in. I was using the 14% and not adding it every day. I dumped the 31% in yesterday and it corrected quick. I've actually had my swg off right now. I added some cya a few days ago and my generator was set to 80%, so I'm a little high right now. It's in the upper 80's this week, so I'm sure it will burn off pretty fast.

Your TA sounds high for a SWG pool. 60-80 should be your target TA. Adding more MA will help lower your TA.

But the bottom line is that your pool will consume additional MA until the pool is fully cured which can take up to a year. And you will always use more MA than non-SWG pools due to having a SWG.

My TA was at 80 today, so it's coming down too. I will for sure post more results when I get my TF100 test kit. I'm just using a basic one that the pool company gave me. As of right now I'm pretty stoked my pH is normal, my TA is getting into a good range and my chlorine is finally staying put! The temp was 72 degrees today, so 5 or so more and I'll finally get in. My teenager jumped in when it was 56 degrees last month...crazy!
Thanks for the help!

 

[anzura]

I received my TF100 test kit today. It's much bigger than I was expecting. Here's my results...

FC: 3.5 (I've had the swg off for 3 days because it went way high after adding cya)
TA: 100 (back up from yesterday)
CYA: It's between the 20 and 30 mark so I assume 25?
pH: 7.8 (back up from yesterday)
CH: 200

Fill water:
CH: 25
TA: 30
pH: 7.8

Should I leave the Calcium hardness alone? Comparing that with my tap water, I'm assuming it will keep going up? I guess I'm going back to pool store for more cya. Another gallon?

Thanks for the help

 

[mknauss]

I would not add any calcium. Keep our pH at 7.8 (only lower it when it gets to 8).

You do need CYA. If using liquid, get enough to get you to 70 ppm. When you test CYA, if the level is between whole numbers, round up. The vial is logarithmic and extrapolation is not possible.

 

[Mackhatter]

Anzura- your post sounds like my situation. My advice is listen to the brain trust here and don’t go chasing your problems until directed. I didn’t find this place until it was $3000 too late. Have patience, trust the help, and everything will work out.