Where do I start on balancing my water?

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kristenerika

kristenerika

0
Jul 20, 2015
25
Waco TX
Hello, I am new here and have a brand new pool.

To this point the only thing that has been done to my pool water is trichlor tablets while the plaster was curing and 480 pounds of salt added by the pool contractor about a week ago when they turned on the SWCG. I want to start this out right from the beginning. :D I got my test kit from Amazon yesterday and here are the results:


  • Salinity: 3100 ppm.
  • pH: 8.0 (My results were at the top of the visual scale, so the actual value could be higher. I know from running a large aquarium in the past that the pH of my municipal water supply tends to run high. It took 3 drops to produce 7.4 on the acid demand test, if that tells you anything helpful.)
  • Free chlorine: 3.8 ppm (I have been running the pump about 12 hours a day -- during daylight -- and the SWCG is going at 100%. The temperature here is about 100 degrees and the pool is in full sun most of the day.)
  • Combined chlorine: 0
  • CYA: 35 ppm
  • Total alkalinity: 130 ppm
  • Ca++ hardness: 170 ppm

So, in order to start moving toward the ideal values mentioned in the Water Balance for Saltwater Pools article, I need to raise free chlorine a bit, lower my pH to the 7.4-7.8 range, lower total alkalinity to the 60-80 range, raise CYA to the 70-80 range, and raise Ca++ hardness to around 300.

This weekend my kids are going to be out of town, so this will give me a chance to tinker with the water chemistry as needed without them asking me every five minutes when they can get back in the pool. What I'd like to know is where is the best place to start? Does it matter which values I start trying to adjust first?

I have to say that I am a bit nervous. I have read about people having problems with high CYA so I worry about adding stabilizer and overshooting that mark. I also worry about adding a bunch of muriatic acid in order to lower my total alkalinity -- if my pH gets too low in that process do I take any risk of damaging my pump/filter/Stonescape/sealed flagstone coping? In the past when I was managing a 100 gallon aquarium huge water changes to correct mistakes were a bit of a hassle but not a huge deal. Here that's not the case.

Thanks in advance for any advice or reassurance you can provide.

Kristen
 
It is very important to maintain PH between 7.2 and 7.8 in a new plaster pool. After the first year it is still important but less risk to damage to the plaster. Add acid to adjust PH to 7.2 every time it gets to 7.8 and your TA will gradually come down. Don't worry about adjusting TA, just keep your PH in range.

Use Poolmath for your CYA adjustment. Go to 70. It won't hurt if it is 80 or 90. All the problems you read about high CYA is 150, 300 or more. It is easily manageable in a saltwater pool under 100.

What is the CH of your fill water?

Also, being hot and sunny tx, I would set your target FC level to 7 or 8. I keep mine at 8 or 9. It is safe to swim up to shock level for your CYA, so anything under 28 is safe.
 
When you're trying to raise your FC up such a large jump, go ahead and use liquid chlorine (aka "bleach") to boost your FC and save wear and tear on the SWG.

The SWG is good maintaining a constant FC presence, but with all that Texas sun and low levels of CYA, you're asking a lot of it to get it up there since it works so much slower.

I always keep a few bottles of bleach around just to supplement my SWG when needed, and I can keep my SWG running at about 20-30% which extends its life.
 
I re-ran my calcium hardness test this morning, both for pool water (150 ppm) and fill water (130 ppm).

I added muriatic acid to bring pH down to 7.2 and am now aerating with the tanning bench bubbler to bring pH back up a bit (and hopefully lower TA while I'm at it).

I ran the "super chlorinate" cycle on my SWCG overnight and FC is now 6.0 ppm. I've got plenty of bleach on hand, so I can add that if needed.

I added CYA in quantities per Pool Math. It is still in the process of dissolving.

Three questions:

1. Should I attend to my low calcium hardness now? According to Pool Math it is going to take a lot of calcium chloride (489 oz) to take me from 150 - 300 ppm CH. Should I wait until my pH and TA parameters have stabilized for a little while before making this addition or should I take care of this now?

2. What is the reasoning behind maintaining FC at 7-9 ppm as opposed to the 4-6 ppm recommended in the Water Balance for Salt Water Pools article (or the 2-3 that is recommended by the instructional manual that came with my SWCG)? I have waist-length hair that is rapidly damaged by exposure to chlorine. For this reason I would prefer to keep my chlorine at the lowest safe level. Please understand that I am not questioning the advice I have received here -- I just want to understand why I am doing what I am doing.

3. My contract with the company that built my pool includes a month of weekly pool maintenance. The guy came for the first time this past Monday while I was at work and added unspecified quantities and types of stabilizer and "shock". I text messaged him and asked him to please give me particulars on what he did and he has not replied. Should I tell the pool contractor that I prefer to take care my own maintenance starting now or should I allow the pool guy to continue to come for the next three weeks?

The contractor already thinks that I am a bit of a pill (I was always very polite and diplomatic but I am fussy about details and pointed out a few issues during our build) and I am afraid that they will take offense at me telling them that I don't want help with maintenance. As I posted in another thread, before the contractor installed my SWCG I expressed concern that the T-Cell-9 unit (rated for 25,000 gallons) that they intended to use would be undersized for my 22,000 gallon pool. The contractor whipped out his calculator and told me that my pool was only 18,000 gallons and that the T-Cell-9 would be just fine. I have since confirmed that the pool is, in fact, 22,000 gallons. Had I known that prior to the installation of the SWCG, I would have sprung for the additional expense of the cell that is rated for 40,000 gallons. I let the contractor know about their math error and they still insist that the T-Cell-9 will be adequate but that we can wait and see how things go. I am afraid that if I insist on doing my own maintenance from the beginning that I will lose any chance of them being willing to swap out the T-Cell-9 for the T-Cell-15 (because they will attribute any trouble with maintaining FC to my novice, internet-guided efforts as opposed to a small SWCG in a very sunny pool).

Thanks for your help!
 
Hi Kristen,

Acutally, TA is the last of the parameters you want to adjust. Doing it early will cause you to have to bounce back and forth.

Here is my recommendation on which order to balance.
1. Add CYA, using the target in Pool Math that you targeted, consider your CYA to be that (it wont show up on the test for a few days, but its there).
2. With new plaster, keep your pH in the 7.6-7.8 range. You will need to test every day and adjust with MA. New plaster has a habit of causing the pH to rise very quickly and you dont want it to get abve 8.
3. Keep your FC at the recommended range. The FC depends on the CYA level you targeted.
4. Go ahead and add calcium chloride to get your CH up to between 250 and 300, you dont need to be exact, just within that range.
5. Adjust TA over time, as your pH rises, and it will, you will use MA to bring it back down, and at the same time it will bring down TA a bit. So, over time, the TA will get down.

Nothing wrong with being agressive on the TA to get it down, but do it after all of the other parameters are adjusted and you are confident in your testing and using pool math and have a good understanding of the effects of being agressive will have.

As to the questions you asked.
1. Yes, you need to get calicum in the water quickly.

2. The TFP FC recommendation is because CYA buffers the effective chlorine in the pool. The CYA binds it up and acutally it is not effective anymore as chlorine. Its a percentage factor of FC to CYA. 7.5% miminum and 11.5% at the top end of the range. So for example, If your CYA is 30 as recommended generally by the pool industry, and using the Pool industry FC recommendation of 3, then the FC level is 10% of the CYA level.

Using the TFP recommendation of CYA 70 for a SWG and the TFP recommendation, your FC at 10% of the CYA would be 7. So, its the same % effective chlorine in the water.

The pool industry, does not acknowledge this FC/CYA relationship, and that as your CYA rises, so must the FC to keep the pool sanitary and free of algae. If they did and everyone maintained the proper FC levels, then no one would get algae and they could not sell all of the snake oils that they do. If there is 1 thing to remember, the pool industry has no intention other than to sell you whatever they can. Its how they make their living. Whether or not their product is relevent to the cleanliness and ease of upkeep to your pool is of no real concern to them.
- Here is a scientific discussion and breakdow of the FC/CYA. This is the science behind the TFP recommendation for FC.
Pool Water Chemistry

3. This a tough one. I guess I would say talk to the PB about ugrading your cell to 40K one and see if you can find a mutual agreement. If so, then continue the maintenance, for the month, but test your own water anyhow so you can sort of determine what they did or didnt do.
After the month. End it.

If you cant get a mutual agreement on the SWG, then go ahead and end it now.

Hope this helps,
 
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