Opening pool and water not balanced

[eddiejo]

Hello,

It's been a year and a half since last refill and setup. I haven't done a complete water test since last year. Getting ready for the new swim season and my recent TF-100 test results are off. I live in the Las Vegas desert. Water is clear but my plaster isn't the best. I have some plaster cracks that require underwater sanding and epoxying which I haven't done yet. I was waiting for them to fully exhaust. I have used the tan eraser to remove some of the dark circle-like plaster staining. I also have some new light tannish plaster staining around floor cleaning popup jets and around the sides of pool. It's only slightly noticeable. I read I should only do half drains so I don't remove too much pressure from the plaster. I'm not sure where to begin correcting these test results:

FC 2.0 <-- I noticed I fall from 3.0 to 1.0 within a couple days instead of the usual few days to a week
pH 6.7 <-- I had just added some. My pH gradually rises from 6.7 to 7.8/8.0 in a week
TC 1500 <-- Not sure how that happened
TA 20
CYA 0 <-- Filled tube and could clearly see black dot

Freshwater pool is about 18,000 to 20,000 gallons. I only use liquid chlorine and acid. I used shock at last setup and got CYA up to 30.

Thanks in advance for any help.

Ed

 

[mariane]

Start with getting your CYA up to 30 and FC to recommended levels of 4 to 7.
What is TC? If it's total chlorine it is not useful so you can skip it.
What is your CH? Post the number.
Your pH and TA are way too low. You need to get them up because that will cause problems for you.
Pool math will give you all the recommended levels. PoolMath - Trouble Free Pool
That should get you started.

 

[ajw22]

Right now your priorities should be your FC and your pH/TA.

Your plaster is "Not the best" because of to aggressive water situation created by the low TA. Do you have any idea how it got there?

Test the pH, TA and CH or your fill water.

Use PoolMath to calculate the Baking soda needed to raise your TA to 70. That should also raise your pH.

Get your pH & TA up and then you can deal with your chlorine and CYA.

@mknauss baking soda or washing soda for this pH/TA situation?

 

[mknauss]

First question is what is the 1500 for TC? If that is a good CH test result, time to change out the water in this pool.

 

[eddiejo]

Sorry. I meant CH not TC. My CH is 1500.

I have no idea how my levels got there. I am going to test my fill water today, maybe tomorrow.

Where should I start? I would prefer not doing a refill because of my plaster but I guess I can do a half fill.

Should the focus be getting CYA up, then TA? Or should I address the CH first?

Thanks!

 

[ajw22]

Address your CH. Your water is not manageable at that CH level.

What is the pH, TA, CH of your fill water?

You can do a drain or we have a no drain water exchange process - read Draining - Further Reading

 

[eddiejo]

I just did a fill water and current pool water test:

Fill Water:
FC 0
pH 7.4
CH 250
TA 140
CYA 0

Current Pool Water:
FC 1.0 <-- I'm going to add liquid chlorine right now
pH 7.5
CH 1300-1500
TA 20
CYA 0

Do you recommend a complete drain, refill and setup? Also, it's only been a year and a half since my last drain and refill, do you have any ideas what is causing the CH levels to rise so fast. The guy at Leslie pools says it's the liquid chlorine I'm using because it's 90% salt water.

Finally, I really don't want to drain and refill it seems like my last setup didn't last very long. Is there anything I can do to last one more season without doing and serious damage?

Thanks!

 

[mknauss]

CH levels rise due to evaporation or adding calcium based products -- but -- you must have been using cal hypo 'shock' for it to rise that far in 18 months. I have the same fill water (Colorado River water) and my CH goes from 250 (fresh fill) to 800 in about 18 months, or a bit longer.

And the Leslies guy is not very well informed. Liquid chlorine does not add calcium.

 

[eddiejo]

The only chemicals I added to the pool in the last 18 months have been liquid chlorine and acid. I believe I used a shock to raise my CYA from 0 to 30 when I first setup the fresh fill but that's it.

So at this point can I raise the CYA and address the low TA levels and try to get one more swim year in, or should I drain and fresh fill and start over?

Thanks!

 

[mknauss]

Up to you. You will form scale. A significant amount. If you are going to do a full remodel next year. Try it out.

The only other way for your CH to get that high was your pool water was very acidic and dissolved your plaster. That may be it.

 

[mknauss]

You should plan to inspect/replace your heater when you remodel. I suspect it is compromised by long term acidic water conditions.

 

[eddiejo]

I guess I will drain and refill. 18 months ago I did get an acid wash on my plaster when the pool was drained. Maybe that's what is causing the high CH. Thanks for you help everyone!

 

[eddiejo]

I drained my pool a little more than half way. Took about 5 hours with a .5 HP sump pump. Three garden hoses and 7 hours after that, the water was filled back up. I let the pool pump circulate the water for about 7 hours and did another CH test. I started at about CH 1600 ppm and after the partial drain an refill I am now at CH 1000 ppm. Also, I cleaned out cartridges and filter. Unfortunately, the desert heat is back and we are at 100 degrees all this week. I was thinking about starting tonight at 6pm and draining until midnight and then filling back up until 8am. We bought the this house 4 years ago and I don't know the age of the plaster.

What should I do? Should I continue with my plan for tonight? Should I wait until winter to drain and refill? Thanks!

 

[mknauss]

You can do partial drain and refills. One more like you just did will get you to 500 ppm CH or so. That will last a year or so.