Newbie - please help look over test results. Am I doing this right?

[Fluorescent_Frogs]

Hey y’all. I just started taking care of my pool a few weeks ago, after ending service with my pool company (too expensive). It’s been good and fun so far, but could use another set of eyes on my test results to make sure I’m doing everything right.

Since Sept 8 I’ve already used a gallon and a half of 20 baume muriatic acid and two and a half gallons of 12.5% liquid chlorine. It seems like a lot - is it?

I did notice right after taking over the pool, that my TA was high (120). TA has been dropping week by week. Previous company was using chlorine pucks so my CYA is around 70. However they also would let my chlorine get to zero almost every week since they only came out once a week.

It seems like I’m adding at least a couple cups of liquid chlorine every day or two, and muriatic acid every few days. I’ve been testing a lot to get a sense of how it all works.

I’m in central Texas and it’s still hot (100 degrees), so I’m not sure if that makes a difference in the take up of chemicals. I notice my chlorine level drops a point or two every day, and my pH drifts up to 8.2+. I’m using the TF pro test kit.

I’ve added screenshots of my test results and chemical additions. It’s a plaster in ground pool with a spa spillover. I measured it to be 18,000 gallons. (Pretty fun to see me remember all my geometry from school trying to figure out the size! I have an odd kidney shape pool with sloped depth).

And last question, I have to go on a trip for a week next month. How in the world do I keep the chemicals stable if they’re drifting like this on a daily basis??

Thank you!! So much to learn here and you all are a wealth of knowledge

 

[ajw22]

The Trichlor tablets added both chlorine and acid and you never saw how much your pool needed. Now you are adding it individually and see the amounts.

Your TA of 110 causes your pH to rapidly rise. If your Ta gets down around 60 your pH will rise slower and use less acid.

Do you have water features or a spa spillover running that causes aeration which causes your pH to rise?

pH rising and chlorine being consumed by the suns UV 2- 4ppm per day is normal pool chemistry.

Get a tablet floater and put trichlor in it for the week you will be away.

 

[JJ_Tex]

Looking pretty good, just keep an eye on your chlorine. At CYA of 70, you want to stick to your target FC of 8-10 or even a bit higher. And stay far away from the minimum of 5.

 

[sande005]

If you go into settings in Pool Math, you can link your logs to your user name here, and then we can see your logs directly - no need for screen shots!

Your TA is high, so it is forcing your pH to rise, hence the MA adds. But as you have seen, adding acid also brings down TA, although slowly. You can speed it up a bit by bringing pH down to about 7.2, and when it nears 7.8-8.0 hit again to bring it low. As your TA gets closer to 60-7 0 your pool will need less and less acid, and may stabilize for long periods in the high 7's.

With CYA of 70, you're flirting with going too low on CL. Get it up to the 8-10 range. After that dose, the daily adds won't be much more than now to keep it there, and it gives you a safety factor if you miss a day, have a lot of swimming, etc.

While we frown on tablets - a couple in a floater won't add a significant amount of CYA, and can help keep it all chlorinated while you are gone. I myself would also boost it with liquid to 12 or 14 just before leaving, just to make sure. You can go all the way to 28 (SLAM level) safely with that amount of CYA, but with the floater may be overkill.

 

[Fluorescent_Frogs]

The Trichlor tablets added both chlorine and acid and you never saw how much your pool needed. Now you are adding it individually and see the amounts.

Your TA of 110 causes your pH to rapidly rise. If your Ta gets down around 60 your pH will rise slower and use less acid.

Do you have water features or a spa spillover running that causes aeration which causes your pH to rise?

pH rising and chlorine being consumed by the suns UV 2- 4ppm per day is normal pool chemistry.

Get a tablet floater and put trichlor in it for the week you will be away.

Thank you!

Yes, I have a spillover and I have the pump running from 10am to 5pm. Maybe that’s too long for it to run?

 

[Fluorescent_Frogs]

Looking pretty good, just keep an eye on your chlorine. At CYA of 70, you want to stick to your target FC of 8-10 or even a bit higher. And stay far away from the minimum of 5.

Thanks! Yeah I just found the CYA/chlorine chart and was shocked how often my pool was allowed to get all the way to zero. I’m trying to keep it at 9, but even with the recommended amounts it doesn’t rise as much as the target I set.

Is there any risk in swimming with chlorine levels at 10? I usually add the chemicals around 4pm so the pump can run an hour, but often we like to swim once the sun sets.

 

[Fluorescent_Frogs]

If you go into settings in Pool Math, you can link your logs to your user name here, and then we can see your logs directly - no need for screen shots!

Your TA is high, so it is forcing your pH to rise, hence the MA adds. But as you have seen, adding acid also brings down TA, although slowly. You can speed it up a bit by bringing pH down to about 7.2, and when it nears 7.8-8.0 hit again to bring it low. As your TA gets closer to 60-7 0 your pool will need less and less acid, and may stabilize for long periods in the high 7's.

With CYA of 70, you're flirting with going too low on CL. Get it up to the 8-10 range. After that dose, the daily adds won't be much more than now to keep it there, and it gives you a safety factor if you miss a day, have a lot of swimming, etc.

While we frown on tablets - a couple in a floater won't add a significant amount of CYA, and can help keep it all chlorinated while you are gone. I myself would also boost it with liquid to 12 or 14 just before leaving, just to make sure. You can go all the way to 28 (SLAM level) safely with that amount of CYA, but with the floater may be overkill.

Thank you for the great explanations!

Thanks for the tip about the TA and bringing the ph down. I was just testing daily and adding the recommended chemical amounts, but not testing again after. Speeding up the TA reduction will probably help a lot!

Is a Cya of 70 really terrible? I don’t see on the website any way to bring it down other than draining and refilling :/

Also great tip about pool math - I’ll go dig into the settings to add that.
Thanks!

 

[Fluorescent_Frogs]

Oh also I will add that I tested my tap water and the TA in it is 150. So when I have to add water I guess I’ll just have to test again and make more adjustments?

 

[ajw22]

Thank you!

Yes, I have a spillover and I have the pump running from 10am to 5pm. Maybe that’s too long for it to run?

Do you have any automation?

You should run your pump for a reason..

The main reason to run your pump is to generate chlorine.. if you had a Saltwater Chlorine Generator, of if you were using chlorine tablets, or if using Liquid Chlorine you only need an hour or so to mix the chlorine with the pool water.

The next reason to run the pump is to adequately skim the surface of your pool. This really depends on you. Some people don't want to see things floating in their pools and others don't really care. I run my pump 24/7, as I like to make a little chlorine all the time and I like to skim all the time. I also think my pool looks better when there is a little motion to the water.. But, that is me.. You will have to decide what works best for you.

But I have automation that runs my spa spillover for 20 minutes twice a day.

 

[Fluorescent_Frogs]

Do you have any automation?

You should run your pump for a reason..

The main reason to run your pump is to generate chlorine.. if you had a Saltwater Chlorine Generator, of if you were using chlorine tablets, or if using Liquid Chlorine you only need an hour or so to mix the chlorine with the pool water.

The next reason to run the pump is to adequately skim the surface of your pool. This really depends on you. Some people don't want to see things floating in their pools and others don't really care. I run my pump 24/7, as I like to make a little chlorine all the time and I like to skim all the time. I also think my pool looks better when there is a little motion to the water.. But, that is me.. You will have to decide what works best for you.

But I have automation that runs my spa spillover for 20 minutes twice a day.

Oh that’s a great point. I just thought it all had to run. Keeping the skimmers going does help for me (we have trees nearby and I find it really hard to get the leaves off the bottom, but easier in the skimmer baskets using hair nets). I have an automatic cleaner but it only runs a few hours a day. I used to have a chlorine dispenser (it was still using pucks though), but it broke and I just patched the hole.

I do love the sound of the running pool but I suppose I don’t need it going 7 hours a day! My first pool company told me to run it 1 hour for every 10 degrees warmer it got

 

[sande005]

As far as high Cl - you can safely swim at any level up to SLAM - in your case 28 !

CYA absorbs Cl, but that absorbed Cl still shows up in the FC testing - hence the apparently very high numbers. Only a relatively smaller amount remains free in the pool to sanitize, which we can't measure without a full on chem lab. As that free amount gets used up by the sun or sanitizing, some of the Cl bound in the CYA gets released. So the CYA is a reservoir that helps keep the active Cl consistent. Unfortunately, it is not something that continues to happen as the free Cl gets used - one gets to a point where the CYA essentially stops giving up much. The chart tries to strike a balance between reasonable protection and the costs of the additional Cl needing to be added due to high CYA.