Tired of bad advice from pool company

Hello - I wish I would have found you guys years ago! I'm once again very dissatisfied with advice I'm getting at my local pool store - pretty certain I'm not going back again. I thought I had a better handle on the chemicals!
This is a water analysis report I got today:

Free Available Chlorine - 7 (high) Shocked 2 days ago, stabilized chlorine
Calcium Hardness - 190 (ok)
Cyanuric Acid - 100 (high)
Total Alkalinity - 100 (ok)
pH - 7.6 (ok)
Total Dissolved Solids - 600 (ok)
Phosphates - 200 (high)

So CYA and phosphates are high. I have an in-ground gunite, 28K gallons, some algae growth. And yes, I'm also using 3" stabilized tabs in 2 floaters. After some education today I see it's a mistake to use them AND stabilized granules for shock.
The same shop who sold me both stabilized products now tell me I need to drain the entire pool and refill to get rid of the CYA. Since they could not tell me how "much" over 100 it was, and that some writers say don't worry about a high CYA, others saying yes I need to drain and refill - I'm in chemical confusion again.
My specific questions are in regards to this CYA problem and what my options really are. And, also if this is a good time to switch to bleach chlorination, i.e. the BBB program. I'm getting sick and tired of the expense and see-saw I've been riding with these chemicals.
Anyone's help is VERY appreciated.
keith

Hi Keith;

I'll work down a list:

• don't say, "I won't go back to my pool dealer". You'll need them for some things. It's just that advice may not be one of them!
• Don't worry about high phosphates or CYA yet.
• Don't use any more 'special' chemicals.
• Use the "Best Guess Chlorine Chart". (Link below)
• Do do a dilution test for CYA to get an idea how high it is. (Method below)
• Do switch to a non-stabilized shock for now -- bleach or cal hypo.
• Since you've got algae, do add a 10 ppm dose this evening -- about 5 gallons of 6% bleach.

Regarding your dealer, he/she/it is probably doing what they were taught. They may well believe what they've told you.

Regarding phosphates, don't tough that yet. It *might* be worth dealing with them, but it's messy and you should understand what you are getting into.

Regarding testing, we need to know how you are doing it, so we know whether to trust your results or not. If you don't have one, and don't drain and refill, you WILL need a DPD-FAS test kit (links below). Getting one is a good idea, regardless.

PoolDoc

Links:
best-guess-swimming-pool-chlorine-chart.html
the-BBB-method-of-swimming-pool-care.html
how-to-test-your-pool-without-a-good-testkit.html

Thank you very much - I'll get started researching the links and doing homework today.

Up to now I've been getting testing done at the pool shop, a national retailer. It's always someone different and I've seen them make occasional mistakes before both with my own samples and other people's while I wait in line. Do I trust their analysis? I haven't a clue. Until I follow your advice and get my own testing gear I've got nothing to compare it with.

I've removed the 2 floaters with the 3" tabs. Let me know if that's not necessary.

I'll post with my findings - thanks again!
keith

btw -
links #2 and #4 in your list don't work.

Sorry about that -- fixed #2. #4 doesn't work because I haven't written it yet. This morning has been crazy, and my afternoon is full, and my Scout troop meets tonight . . . so it will probably be tomorrow before I can get it done. I'll post a placemark page, however.

You don't have to take out your floaters -- the safest place for wet trichlor tabs is in the pool anyhow -- just hold off on adding new ones or using dichlor shock till we've actually found what your CYA level is.

Ben

UPDATE: links fixed now.

Keith,
Thanks for the trouble of reposting. Sorry about the accidental deletion. I had replied to your other thread a few minutes ago and then found that Ben had answered you here, so I went back and deleted the other thread. Hope you'll find the Pool Forum to be very helpful to you and also just a fun place to hang out!

I'm soooo glad to have found you guys. You don't know what a relief it is to find some reliable advice and help with my chem-confusion! It's already been helpful and I just sent in my first post yesterday. Looking forward to a long and rewarding relationship! Hope at some point I can pay it forward.
keith

Ben - I bought a Taylor DPD-FAS kit. My CYA is above 100. Extrapolating it looks like 150-175. Probably closer to 175.

Keith,

You can use the "how to test if . . ." link to get an explanation of how you can 'extend' your CYA test to cover the higher range.

Then, use the "Best Guess" page to find the right chlorine range . . . and you should be good to go.

Of course, you'll need to switch to either calcium hypochlorite or bleach (sodium hypochlorite) as your primary source of chlorine.

You can give away, or seal up, your stabilized chlorine. You might want to hang on to it long enough to see how fast your CYA drops (no need to test more than 2x per month). If it looks like it will take more than a year to get below 100ppm, you'd better give it away. Old chlorine tabs and powder tends to give off a variety of noxious fumes that aren't good for you and are TERRIBLE for wiring in your garage or storage shed.

Ben

So help me understand what you're saying, - even with a 150+ CYA level, do I need to drain/refill? And you suggest to "see how fast your CYA drops". I thought the CYA never drops. So I remain in that confused state I started in. What is the resolution to the CYA levels? Leave it as it is and monitor FC levels and forget about it? Drain? Not drain?

The CYA is only going to drop by backwashing or by splashout, so it's possible for it to fall some during the swim season, but not likely by very much. Ben is by far the most knowledgeable one here, and I'm guessing he has a reason for not draining/refilling to get the CYA under better control, and would defer to him, but just wanted to add my opinion here that it certainly won't hurt to drain/refill some of your water, and personally, if it were my pool and could do so without much of a problem, I would go ahead, unless the levels of other chems in your fill water would substantially change the current levels in your pool.

Janet

Keith,

If you'll look at the Best Guess chart (link below), you'll see you can operate in the 8 - 15 ppm range, once your algae is gone. If you have a sand filter, you're going to losing about 1% of your stabilizer every time you backwash, plus whatever splashes out. (If you've got a DE or cartridge filter, it will be less.) But, for now, you can clean up, and operate just fine right where you are, now that you've got a FAS-DPD based kit.

You may find you like it. With stabilizer that high, you can chlorinate on Monday to 15 ppm or so, and not have to add again possibly for the entire week. Since the chemicals you need to use have to be hand fed unless you buy some sort of feeder system, this offers you some real benefits.

Or you may find you don't like it. If so, you can still drain and refill later.

But, until your algae is gone, I'd recommend adjusting your pH to around 7.8 (7.6 is ok) and then dosing to about 25 ppm. (Remember, you can't test pH once you go above 15 ppm chlorine.) Once there, brush every day or so, and dose up to keep it there till your algae is 100% gone. If you find that it's not disappearing, you can increase the chlorine somewhat, or you can look at using a phosphate remover -- but that's messy.

You *can* swim at 25 ppm, if your pool is warm enough. Just wear an older swimsuit, since those chlorine levels are not good for fashion suits. You may, or may not, find that those levels of chlorine dry your skin some.

Ben

Ben

Thank you guys for your replies to my problem. I did dose high with bleach, the pH was good, and the algae is still not reacting. And it has stained some areas of the gunite surface. I'm going to drain today, power wash (delicately) to remove the algae and refill. I don't have a problem monitoring and adding BBB when necessary but I do have a problem brawling with this extreme CYA. Here in North Texas the summer sun is brutal and I can't see starting out with algae growth!

If you would please direct me to one or more of your links or a good post on starting up a pool with fresh (tap) water using the BBB program.

Thanks very much,
Keith

Be careful. Totally draining a pool is often not a very good idea. Particularly if the water table is high. Your pool can literally pop out of the ground. A better option might be to do a couple of partial drains and refills. You can probably safely drain 1/2 to 2/3 of the water. Then, retest cya. If still too high, can do another partial drain and refill. I realize that you have a large pool and this may be a big expense waterwise. However, if you do get the cya to a more manageable level with some partial drain/refills, then we can help you get rid of the algae. Won't be necessary to do a powerwash.

If you do drain and refill, repost with a set of water testing results taken from your fill water. It will be easy to help you get it balanced. Have you done any reading on our sister site www.poolsolutions.com ?? Lots of good info there. Repost with numbers and we'll make recommendations for you to get started off on the right foot.

Hi - in response to your last post, I've drained and refilled. Here are my numbers after refilling based on my K-2005 Taylor test kit. To recap it's a 28K gunite in-ground pool

Free Chlorine - 1.0
Combined Chlorine - 2.0
pH - 8 (acid demand was 2 drops)
Total Alkalinity - 120
Calcium Hardness - 160
CYA - 0

Again my goal is to use the BBB method to balance the water. Your help is most appreciated!
Keith

Did you get a K2005 or a K2006? There's a BIG difference!

Anyhow, get some acid and bring the pH down. Don't worry about acid demand; just add a small dose and repeat till you get there.

If you are going to use bleach or cal hypo, add CYA -- 1# will add about 4 ppm if fully dissolved.

If you are going to use dichlor or trichlor, add less CYA, probably only 5#.

Dunno why you have CC -- unless you've got a K2005. DPD tabs are a pain.


Ben

Two good things about a gunite pool:
1) It can stand very acid water without melting the liner (vinyl is in danger once you go below 6.9)
2) It can stand VERY high chlorine levels, like 50ppm or more (where vinyl will bleach). This is good for clobbering algae but you still can't swim till it comes down to levels Ben recommends.

Now that your pH is high and your stabilizer (CYA) is zero, Trichlor tabs and/or dichlor powder is a good option. Both will lower pH and raise CYA levels.

But with Gunite, your cal is below the recommended 200-400ppm. Cal-hypo is a good chlorinating option for that as it adds calcium.

Personally, though, even with gunite, I'd worry about calcium levels last.

BTW, when your pH is at 7.6 or lower, your T/A will measure lower too, but it should be fine.