First test results with the TF-100

[MikeJetton]

So, I've been using a pool service for the past 10 years and was satisfied with the service but I never checked the water because it always looked good. Also during that 10 years my mobility was not good. I'm doing better now and probably going to do this myself.

Here are my first results:
Free Chlorine - 14
Combined Chlorine - 0
Total Chlorine - 14
Calcium Hardness - 800
Total Alkalinity - 120
CYA - 100
My filters need cleaning Hayward Swimfree 425.
My Action Plan - Discontinue Trichlor tabs until CYA is in acceptable range and only use liquid chlorine as needed. I'll be checking chlorine daily. Will monitor CYA and if and when it gets to 30-40 use tabs occasionally to maintain that level. Regarding PH - pool math tells me to add 9.8 oz muriatic acid. For the Total Alkalinity - adding the muriatic acid should help. The only way I have to aerate is to run the blower on the spa. Would that be a good idea and if so - how long? For the calcium hardness - pool math tells me to replace at least 25% of pool water by volume with our tap water that is at 200. On this suggestion I will say that due to evaporation this time of year we add about a 1 to 1.5 inches of water to the pool every day, so maybe this will resolve over time. Not sure what the pool service were using, but could Calcium Hypochlorite use have caused such a high calcium hardness? Filter cleaning maybe today. I welcome your thoughts.

 

[PoolStored]

Redo the CYA test starting at #8 here and report back.

CYA - Cyanuric Acid Test

Cyanuric acid (CYA) is the chemical name for the product commonly called “pool water stabilizer” … Read more…

www.troublefreepool.com

Discontinue Trichlor tabs until CYA is in acceptable range and only use liquid chlorine as needed. I'll be checking chlorine daily. Will monitor CYA and if and when it gets to 30-40 use tabs occasionally to maintain that level.

We may need to replace some water if your CYA is higher than we think.

Regarding PH - pool math tells me to add 9.8 oz muriatic acid. For the Total Alkalinity - adding the muriatic acid should help. The only way I have to aerate is to run the blower on the spa. Would that be a good idea and if so - how long?

Its fine plan. I'd manage pH. I would lower it to 7.2, this should also lower TA. pH will rise on its own. When it gets to 8.0, lower to 7,2 again. Do it in .4 increments and test and add more 30 minutes later until it gets to 7.2.
When your TA is down to around 60-80, pH should be fairly stable around 7.8.

For the calcium hardness - pool math tells me to replace at least 25% of pool water by volume with our tap water that is at 200. On this suggestion I will say that due to evaporation this time of year we add about a 1 to 1.5 inches of water to the pool every day, so maybe this will resolve over time. Not sure what the pool service were using, but could Calcium Hypochlorite use have caused such a high calcium hardness? Filter cleaning maybe today. I welcome your thoughts.

Your CH will continue to rise. Evaporation does not reduce CH, it stays in the pool. You add 200ppm fill water, you are increasing CH over time. 800 is really high.

It would be best to replace maybe half your water. That would get CYA to 50 (if it is really 100) and CH to about 400.

Do the CYA test, then we can figure out a plan of action.

 

[pjt]

we add about a 1 to 1.5 inches of water to the pool every day

That's a lot. You might have a leak. I'm losing around a quarter inch on the hottest days.

 

[MikeJetton]

If I'm going to replace that much water, it seems like I should do that first then test again to see what is needed. I don't understand how my calcium hardness could be so high. Could it be from using too much Calcium Hypochlorite over the years? If my fill water (Tap water) is at 200 PPM hardness how could that be increasing CH over time? My bad if I'm not understanding.

 

[PoolStored]

If I'm going to replace that much water, it seems like I should do that first then test again to see what is needed.

Correct.

I don't understand how my calcium hardness could be so high. Could it be from using too much Calcium Hypochlorite over the years?

Yes, and your fill water.

If my fill water (Tap water) is at 200 PPM hardness how could that be increasing CH over time? My bad if I'm not understanding.

Yes. CH is only removed when you remove water. It stays in with evaporation.

 

[MikeJetton]

I'm gonna back track on the water loss statement. Evaporation probably causes 1/4 to 3/8 per day loss.

 

[MikeJetton]

I want to follow up on this thread because I implemented my plans to clean the filter and drain water and then retested and added the appropriate chemicals that the TF-100 and Poolmath app suggested. I started at 7:30AM - My main pump was off for a full day while draining the water. I got a 1/3 hp Drummond submersible pump from HarborFreight that claimed it could pump close to 2000 gal per hr with a 5' lift. I was disappointed because I thought it was only pumping about 300 gal per hr. So - that took about 12hrs to drain about a foot of water - which is maybe 3000 gallons or so of my 13,500 estimated gallons. Later I read in some post (I did not document) that using an expandable hose reduces output and I should have used my 3/4 solid hose. There was nothing about this in the pump's manual. Maybe I'll try that if there is a next time. It took about 7 hours to fill the pool back and that finished around 2 AM. I tested the water again first thing in the morning and the TF-100 suggested 3 quarts of 12% chlorine to get to 10-11 PPM (it was down to 1) and 21oz of muriatic acid. I added the acid first at a return outlet by measuring it into a container and then slowly pouring it in - trying to stay up wind. Then I waited 30 mins and did the same with the chlorine. NO TRICHLOR!!! No Calcium hypochlorite!! It seems our tap water is around 120 total alkalinity so I'm not concerned with adjusting it. I'm glad I found this website and thanks to Poolstored! I reduced the calcium hardness and CYA - my main objective!


Test results:

	Before	After
Free Chlorine	10	11
Combined Chlorine	.5	0
Total Chlorine	10.5	11
Calcium Hardness	650	575
Total Alkalinity	120	120
CYA	100	65
PH	8.2	7.8

 

[MikeJetton]

One more thing. I have taken over responsibility of my pool care. I did use someone for years and I thought he did a good job, but I never checked the chemicals in the water. Then he merged his business with someone else and handed me off to them. I have the free time to do this myself and same some money too!

 

[pjt]

I added the acid first at a return outlet by measuring it into a container and then slowly pouring it in

It's safest and easiest to pour directly from the bottle into the pool. The more it's handled, the more likely there will be a spill or splash incident. Minimize risk when handling MA.

Slowly pour MA in front of a return with the pump running. Hold the bottle a couple feet from the coping and ~1" above the water. If you pour in a slow and controlled manner, it doesn't splash. If there were any splashes, they would land in the water. You can partially submerge the bottle and use its buoyancy to assist. Open and close the bottle over the water. When done pouring, cap the bottle tightly and dunk in the water to clean off any residual MA that may be on the outside of the bottle. Brush the area and you're done.

 

[pjt]

Total Chlorine

No need to list total chlorine. FC and CC is much more useful.

What's the CH of your fill water?

You're an excellent candidate for a SWCG. It will save you much money, time, and effort.

 

[PoolStored]

Great job!!!