What to do first? CYA > 200 ppm

[PoolLizard]

Hello,

21,500 gal, IG pool. Just got a new K-2006 test kit and here are the test results:

FC = 4.4
CC = 0.2
pH = 7.4
TA = 150
CH = 560
CYA = 200+ (I'm guessing here. It's way beyond the scale)

Fill water CH = 60ppm.


From what I've read, the most recommended way of lowering CH, and CYA, is to drain and refill. But, somewhere else on this forum I read a post by PoolDoc of another way. I can't find that thread now. So, what's the best/cheapest path for me to take?

[PoolDoc]

1. Assuming your pool is algae free, raise your chlorine level to above 10, and keep it there, till you have more information and another plan. When CYA > 100 ppm, swimming with chlorine > 20 ppm is no problem. Use the 10ml sample to test chlorine, so you don't use up your R0871 drops.

2. Read the Best Guess page, linked in my blue signature block.

3. Tell me if you have any sort of heater or salt water chlorination system. Tell me if you are currently having any scale appear.

4. Tell me what kind of pool you have (vinyl, FG or concrete) and whether the ground is dry in your location. (S Calif, so I assume it is, but please confirm).

5. Do NOT use any algaecides or other such products.

6. Mix 1 cup of pool water with 1 cup of tap water. Test CYA levels in the mix. Multiply result x2 for actual pool CYA level.

7. Tell me what you've been using to chlorinate.

8. If you have NOT been using cal hypo, but have some idea where the calcium came from, please explain.

9. Do NOT worry about CC levels, even if they go up a bit.

10. Tell me what sort of filter you have.


Good luck!

[PoolDoc]

Hm-mh. I just processed your registration and upgraded your membership -- you included your address, and Google Maps has a high res of your pool . . . SO I can see ground water won't be a problem. Unless you've just had a flash flood, you can drain safely.

Unless water is very expensive, or there are no-drain rules in place It would certainly be easier to drain, than to do lime-softening.

But, lime softening would probably be cheaper . . . IF you have a way to vacuum to waste. What will happen is you'll deposit lime dust all over the bottom of your pool, and then have to vacuum it out, dumping it on the ground. Afterwards, you'll have VERY high alkalinity, and will have to lower it. You'll probably replace a foot of water.

However, this will NOT lower your CYA more than what would be removed with 1 foot of water, so we need a better idea on your real CYA level. The only practical way to lower CYA is to let it be biodegraded, which means DELIBERATELY letting your pool get slimy for several weeks. Even then, it's a crap shoot -- with no guarantees. The right bacteria may not show up, OR you may find that the CYA degrades to ammonia (HUGE mess) rather than nitrogen gas. So, it's a risk, not worth taking unless the water situation is dire, and your CYA is truly too high to handle. DO read the Best Guess page.

[PoolLizard]

Thank you PoolDoc/Ben - I will be working on your list today, I'll get back with a complete report as soon as I can.

I'd like to go ahead a drain about a foot of water, and refill, BEFORE I put in a lot of new chlorine. And then see where the readings are. I'd like to see how much replacing one foot of water will help. Water here is very expensive, but I've come to the conclusion that I have to "bite the bullet" anyway.

Suggestions?

Thanks!

PoolLizard

[PoolDoc]

Before you drain, you need to decide whether you want to do lime-softening to remove calcium. If you do, you'll end up draining and replacing a foot of water, as part of that process. What I'd recommend is that you follow this sequence:

1. Raise your chlorine level and keep it there

2. Retest with the K2006, to verify the high calcium, and to do the dilution test on the CYA

3. Report how the calcium arrived in your pool. This is very important -- it will do no good to remove some calcium, if it's just going be added again, somehow or other.

4. Make SURE you understand the Best Guess page, and then let me explain what it requires to run the HiC2 method (high CYA / high chlorine). If you do NOT want to do this, and your CYA is actually > 200 ppm, you'll have to drain 75% or more at one time in order to use more standard chlorine levels.

5. THEN look at all this info with me, and make some decisions about what to do. BUT, it's important to get the chlorine up NOW, so you aren't forced into dealing with an expensive, time-consuming, and ultimately wasteful algae problem.

[PoolLizard]

Before you drain, you need to decide whether you want to do lime-softening to remove calcium. If you do, you'll end up draining and replacing a foot of water, as part of that process. What I'd recommend is that you follow this sequence:

1. Raise your chlorine level and keep it there

2. Retest with the K2006, to verify the high calcium, and to do the dilution test on the CYA

3. Report how the calcium arrived in your pool. This is very important -- it will do no good to remove some calcium, if it's just going be added again, somehow or other.

4. Make SURE you understand the Best Guess page, and then let me explain what it requires to run the HiC2 method (high CYA / high chlorine). If you do NOT want to do this, and your CYA is actually > 200 ppm, you'll have to drain 75% or more at one time in order to use more standard chlorine levels.

5. THEN look at all this info with me, and make some decisions about what to do. BUT, it's important to get the chlorine up NOW, so you aren't forced into dealing with an expensive, time-consuming, and ultimately wasteful algae problem.

Okay, I'll go ahead and raise the chlorine level up today. And I'll check the CYA using the 10ml sample method.

I'll let you know when that's all done.

Thanks!

[PoolLizard]

I'm going to go ahead and answer as many of your questions as I can right now, and complete the rest later. See my responses inside [] brackets.

1. Assuming your pool is algae free, raise your chlorine level to above 10, and keep it there, till you have more information and another plan. When CYA > 100 ppm, swimming with chlorine > 20 ppm is no problem. Use the 10ml sample to test chlorine, so you don't use up your R0871 drops.

[Upon your approval, I'm going to replace about a foot of water, then do a complete water test to see where the numbers are. Then raise the chlorine level.]

2. Read the Best Guess page, linked in my blue signature block.

[Done, but I may have to reread it a few times to completely understand.]

3. Tell me if you have any sort of heater or salt water chlorination system. Tell me if you are currently having any scale appear.

[I do have a gas heater, but it is not used, it is bypassed. No salt system.]

4. Tell me what kind of pool you have (vinyl, FG or concrete) and whether the ground is dry in your location. (S Calif, so I assume it is, but please confirm).

[I believe it is a concrete pool. Yes, the ground around the pool is dry. This is in the Mojave Desert.]

5. Do NOT use any algaecides or other such products.

[Just before I registered in the forum, I had put 3 ounces of HTH Super Algae Control into the pool. Okay, I won't use any more. ]

6. Mix 1 cup of pool water with 1 cup of tap water. Test CYA levels in the mix. Multiply result x2 for actual pool CYA level.

[Okay, will do.]

7. Tell me what you've been using to chlorinate.

[I *had* been using Trichlor tabs in two floaters, and Calcium Hypochlorite granuals, until I started reading this forum. I have pulled the floaters out, and switched to 10% bleach liquid chlorine. I basically have ignored this pool for the last 9 years. I had a job that required me to travel 200 miles round trip each workday. All I had time to do was eat, sleep and work. Now, I am retired and so I have more time to attend to the pool. So, just this summer I have gotten serious about getting the pool in ship shape.]

8. If you have NOT been using cal hypo, but have some idea where the calcium came from, please explain.

[See #7 answer.]

9. Do NOT worry about CC levels, even if they go up a bit.

[Okay]

10. Tell me what sort of filter you have.

[I have a PAC-FAB FNS 60 DE filter with just a simple push-pull up and down backwash valve.]