Rain and Alkalinity

[VinDeeLoo]

Every post I have read says that rain lowers alkalinity. I am fighting high alkalinity - I had got it down to 275 from 313). We got a hard rain last night (after putting in pH Decreaser). This morning when I did my testing I was very surprised to see my TA up to 320. I added another pound of pH Decreaser. Within 15 minutes of adding it, we got another big thunderstorm. What could be making my TA go up so much?

How often can I add the chemicals to continue lowering - knowing that the pH needs to be up to 7.5 to add more?

These are this mornings readings from my Taylor K-2006 test kit.
FC 7.5
TC 7.5
CC 0
pH 7.6
TA 320
CH 275
CYA 0

 

[JoyfulNoise]

Rain water typically has low pH and very little TA. But that is atmospheric sampling. Once rain hits the ground or stone work, it's pH and TA will change as it absorbs alkaline materials (like calcium).

That said, rainwater has little to no effect on pool chemistry unless you are draining off inches of pool water per day. If you know your pool surface area you can calculate how much water 1" of rain is. In my pool, it's just shy of 300 gallons which is about 1.8% of the total volume. Adding an inch or two of rainwater will have no measurable impact on my water chemistry.

High TA comes from chemicals like baking soda or washing soda (soda ash) additions or high TA fill water. That's it. Rain is not a factor.

Strong rains can cause pH to rise from aeration of the surface water but that is related to the high TA of the existing pool water and not because any additional TA is added.

 

[VinDeeLoo]

That is what I thought, but I haven't added anything to increase TA. I have just added pH Decreaser, Stabilizer, and Chlorine. We do have high alkalinity and high CH fill water.

How often can I add the pH Decreaser?

 

[JVTrain]

Reduce pH any time it rises above 7.8. Using muriatic acid rather than pH reducer (powdered) is better for your pool over the long term and less expensive. You can certainly use up what you have, but go for muriatic acid if you run out of powdered pH decreaser.

 

[VinDeeLoo]

I will do that. We live in a small town (1 traffic light town) , so I was limited. Does Walmart or Lowes sell muriatic acid? They are the closest to us town wise. (Still a couple towns over.)

 

[JVTrain]

Most any hardware store whether it's Lowes, Home Depot, Ace, Hardware Hank... etc. will likely carry muriatic acid. It's in the paint section most of the time.

 

[VinDeeLoo]

Thank you!

 

[Texas Splash]

Muriatic Acid (Lowes):

 

[VinDeeLoo]

One more question, (I think). Do I need to bring the pH back up to 7.5 before adding the next dose? (of muriatic acid or pH Decreaser)

 

[Texas Splash]

When lowering TA, lower pH to 7.0, then let the aeration raise the pH all the way back up to 7.8 before smacking it again with acid. Members have had more success with using that full range of motion to get the TA to move better.

 

[VinDeeLoo]

Thanks!

 

[VinDeeLoo]

Just found out our little hardware store carries muriatic acid. Rain has put h2o level to the top of skimmer. Lowering h2o and will start up again. Aerating pool why I lower level. Really need to talk hubbie into a light/fountain to help with aerating - since I will be doing this for a while.

 

[Texas Splash]

Something like one of these will work:

 

[VinDeeLoo]

I would like to do that, but we only have 1 return right now. Next year I plan on modifying the pool for a swg pump system.

 

[camueller]

I would like to do that, but we only have 1 return right now. Next year I plan on modifying the pool for a swg pump system.

another option is to get a submersible pump and use that to drive the fountain/aeration rig. I have the one below. It has a 1 1/4 male thread, so I took a female PVC threaded end, mated it to some 1 1/4 pvc and T'd it off at the top, drilled holes in it, and let it run.

Superior Pump 1/4 HP Submersible Thermoplastic Utility Pump-91250 - The Home Depot

Here is a link to the thread I started when trying to figure out how best to aerate, so you an see my pump in action.

building the most efficient aerator

 

[VinDeeLoo]

Thanks!

 

[wkhedr]

I can't imagine rain or any other natural event raising TA to 300. This is like someone is intentionally pouring chemicals in the pool.

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[VinDeeLoo]

No, we have no children. It is just the 2 of us and we don't have anything to raise pH and TA at the house. We also live in an older community - we are the youngest ones on our block.

 

[ta2dwonderwoman]

Just found out our little hardware store carries muriatic acid. Rain has put h2o level to the top of skimmer. Lowering h2o and will start up again. Aerating pool why I lower level. Really need to talk hubbie into a light/fountain to help with aerating - since I will be doing this for a while.

I got an amazing hydro powered fountain for cheap at wally world ... it needs a valve to control the fountain as it does go clear across my 22 ft round pool so I need to dial it back a bit...

http://www.walmart.com/ip/Intex-Mult-Color-LED-Pool-Sprayer/47715419

 

[VinDeeLoo]

Thank you ta2dwonderwoman. We found this fountain on clearance for $15. We love it!


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