Need help with chemicals

[shaneanderson81]

Hello All,
This is my first time posting. I have an in-ground pool that is approx. 15,000 gallons and plastered walls. The pool is roughly 30 years old. The water is clear but emerald green. I recently purchased a TF-100 test kit and used it for the first time today. I live in California and my thermometer says the water is 53 degrees F. The results of my tests are as follows:

10 ppm FC
0 CC
TA=60
CA=60
pH=7.2
125 ppm CH

I attempted to use the PoolMath calculator and I came up with this list of chemicals to buy and add to the water:

17 oz soda ash
140 oz baking soda
300 oz calcium chloride
(all oz are by weight)

The calculator also said to drain 25% of the pool water and replace it to lower the CYA. Is this a necessary thing? I'd rather not if it's possible, just because of our drought. If I have to replace water should I do that and then retest the water? I assume the amounts of chemicals I need to add would change due to dilution. Or, maybe the calculator takes that into consideration? Also, is there any order I need to add the chemicals in? Do the chemicals and their amounts I got from the calculator sound correct? Any suggestions would be greatly appreciated.

Thank you in advance,
Shane

 

[pooldv]

Welcome to TFP and maintaining your own pool. It is good stuff. You'll have all this stuff memorized in no time!

Is your CYA 60? 60 is fine, your pool is manageable at that level. Just maintain FC according to the Chlorine CYA Chart.

TA at 60 is fine. If your PH is stable then leave your TA at 60. PH needs to be maintained between 7.2 and 7.8, 7.5-7.6 is ideal. PH and TA are the only two things tested and adjusted that are interrelated.

I would raise your CH to 250. Do you have soft water there?

Otherwise, everything looks pretty good. Nice first post! Is your water clear?

 

[Texas Splash]

Hello Shane from Roseville, and welcome to TFP. I was at Beale AFB for a few years so I am somewhat familiar with your area - although it's probably grown 10-fold from when I was there. Nice to have you with us. Good job on the TF-100.

 

[Isaac-1]

Welcome, I would retest before touching the CH, I don't know your exact area, but most of the Southwestern US fights against high CH due to a combination of high CH fill water and evaporation concentrating it even more. Having said that how have you been maintaining your water, clear emerald green water is a sign of metals in the water? Do you have a metal ion system, have you been using copper based algaecide, etc?

 

[gwegan]

Welcome to the forum, I'm just down the road from you.

If your cya is 60 I would do nothing in that regard. I woul let it drop to 40 over time. All the rain should be deleting it down so make sure it stays above 40.

Has it always been the green tint? You might consider a metals test.


Roseville has well water so I'm surprised at the low ch. that makes no sense. I would retest.

On the whole your pool looks good.

 

[duraleigh]

A pic of that clear, green water would help with the diagnosis. Did it suddenly turn green? If so, when.

Give us a little more background but I suspect iron in your water.

 

[Richard320]

I also question that CH reading. Did you maybe use the wrong factor when multiplying drops to get PPM? That's really common. Most of the year, my tap water is higher in CH than your pool! And was the water well-mixed with the pump running when you drew the sample?

60 CYA is just fine where you live. I wouldn't drain it just for that.

My advice is to repeat the tests making sure the water is well mixed and the sample was drawn a few feet from the surface and the walls. Hint: a short length of 1/2" PVC pipe makes a good pipette. Plunge it in, cap it with your thumb, pull it out, and release it into your sample bottle. Also take multiple readings off the CYA sample. Pour it back and shake again and take another reading. The CH test needs to go until it turns sky blue. Not purplish or indigo, but sky blue.

 

[JoyfulNoise]

Another thing to keep in mind is this - when you use PoolMath, you put your measured test results in the "NOW" column and you put your desired results in the "TARGET" column.

People often put the TFP recommended levels in the TARGET column and that generates a long list of chemical adjustments. The fact of the matter is, pH and FC are the most critical parameters to get right and the rest may not need any adjustment depending on your location and fill water parameters.

Also, don't use soda ash to raise pH. It will also raise TA a lot and you don't want that. Use borax to raise pH OR just aerate your water by brushing it or running a water feature and your pH will creep up over time naturally.

You were correct to ask first before rushing into buying all those chemicals. Get your pH and FC set right and then we'll consider the rest.


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006