Confused Newbie needs CYA advice

Hello everyone –

I live near Dallas TX and I have a 7 yr. old pool – I had never had one prior to this so I have been going along with whatever the pool store told me to do. But this spring I haven’t been able to get the algae under control and had to shock it every few days or it would show up in the corners or sides almost overnight. When I took a sample in recently they said I had high CYA which is what was causing the chlorine to not work and that I would have to continue to add a lot of it or drain the pool and start over. I drained about a third of it the other day and refilled but the CYA was still the same as before according to the new test (over 100 ppm). I ordered the Taylor 2006 last night so hope to get that in the next few days but in the mean time I was wondering what I could be doing as I don’t want to introduce anymore CYA but the water is getting pretty green. I’d like to try the bleach to shock it but not sure how much and how often since I don’t have a way to measure the levels yet myself (but could take a sample to the store each day I suppose to get me down the road until I get the test). BTW, I found some great YouTube videos showing how to use the K2006 so I’m feeling a little empowered today and can’t wait to get going with this new program.

I also have some other issues with this pool that I hope I can tackle myself. I would like to try to re-plaster this pool in the next year or so and will be gathering information about that, and hope you have some helpful tips for me there as well.

Back to the CYA, the results of my last test were:
FAC and TAC were 0 (we had three days of hard rain and hail so I didn’t run the pump knowing I would have to shock anyway).
PH 7.5
TA 120 (I use trichlor tabs)
CYA 100
Phosphates 100

My pool stats are: 17,000 gallon in-ground pool, A.O. Smith Century, 2 speed pump, 1.5 – 2.5 HP, RPM 3450- 1725, 190 series cartridge filter.

I had read on the Pool Solutions website that I needed to take the tabs out of the chlorinator and clean that out before I add the bleach or it could explode – yikes – so will do that after I hear back from ya’ll.
Thanks a ton and look forward to hearing from you.

1. Stop using trichlor - that's why your CYA is so high.
2. Add 7 gallons of 6% PLAIN household bleach should get you to 25ppm FC (OTO orange).
3. See if you can get the HTH 6-way kit at your Walmart (check availability)
4. If not, get a cheap OTO/phenol red testkit.
5. Add enough PLAIN 6% household bleach each EVENING to bring your OTO to orange. Filter / pump on 24/7
6. Brush the pool completely at least every other day.

Let us know when you can test CYA for yourself.

Thanks, I'm off to Walmart -

Been there, done that with the high CYA, draining and refilling. I got the same results. However, CYA at 100 is still managable. One thing you need to know is that testing CYA over 100 is difficult. When you do get your Taylor Kit, you might dilute your sample 50/50 with clean tap water, then double the reading to get more accurate results.

As a general rule, the higher the CYA, the more Chlorine you’ll need. The Rule of thumb around here is to keep the chlorine at minimum of 5% of the CYA Reading. So, if your CYA reading is 100, you’ll need to keep you chlorine at or above 5 PPM.

BigDave is spot on correct with his advice. Follow those instructions, and above all else, stop using the Tablets. Each tablet adds more CYA to your pool water.

I bought enough bleach to equal 6 gallons and the OTO/Phenol red test kit. I have been running the pump this morning to keep things moving and have not taken the trichlor out of the chlorinator yet. Thought I would try out the kit right now and the results were .5 Cl and 7.5 pH.
After I clean out the chlorinator, how long should I wait to add the bleach - don't want anything to explode - but I should add it this evening, right?Then after I add the bleach, how long should I wait to test? Thanks.

If your pump is running, you can pour the bleach into the pool, right now! Just don't pour it over the trichlor in the skimmer!

BTW, AO Smith made the motor, not the pump.

Thanks - I dragged all the bleach out there and am about to start pouring. I checked the pump and there was a small label that said Hayward with an ID # and serial # but no other info so I'll see what I can dig up from the original paperwork and send that along with my new test results. Should I test immediately after I add the last bottle or wait a while?

Wait a little while to let it mix.

I just checked and the Cl is 5+ (even more yellow than the top color) and pH is 7.5. Will run the pump all night and see if it is less green in the morning. Hayward got back to me and, for the record, I have a 1.5 HP Hayward Super II pump.

Thanks so much to everyone today for all their help! Can't wait to get the kit to find out what the CYA level really is.... and what I need to do from here.

Until your kit arrives, you can use a dilution method to force your kit to read higher. Not super accurate and doesn't replace getting a good kit, but better than nothing. More about it here:

Testing Without a Good Kit

Hope this helps!

Dark yellow OTO is a good start but i'd be happier with orange. With the apparently high CYA in your pool, you'll need to maintain at least 25ppm FC to clean up the algae.

After your last post, I am beginning to see that not knowing the CYA level is going to keep me from going much further. After adding 7 gallons of bleach yesterday and running the pump all night, visually the water doesn't look much different. The 7 gallons only got me to 5 or 6 Cl yesterday and when I tested this morning the Cl is at 1 and the pH is as 7.2, and I understand that I need to be at 25 ppm to kill the algae. So without CYA info I could be adding bleach all day.... 15, 20 or more gallons to reach the 25 ppm goal. Then who knows how much I would need to continue to add on a daily basis... Wow! I think at this point I should drain at least half of the pool and refill to get the CYA down to a more manageable level in order to moderate the amount of bleach I'll have to add in the future. Will let you know the test results after the drain/refill and after I get the kit with the CYA test in it we will have some actual numbers to work with.

I've read about using a large sheet of plastic to keep fill water separate from the water being drained - this way you mitigate against the possibility of floating your pool out of the ground.

You need a CYA measure for almost everything. Even to know how much water to replace.

Have you ordered a K-2006? You can also buy stand alone CYA kits, even at some pool stores if that's convenient.

CYA tests only measure to 100ppm but you can use the dilution method to measure higher. Mix 1 part pool water and 1 part tap water (tap water has no CYA) test the mix and multiply the result by 2. If it's still over 100, dilute 1 part pool water with 2 parts tap water and multiply by 3. This will give you a range of how much to drain / refill.

He has the K-2006 ordered.

If you decide to use the sheet method, you need a very large piece of plastic sheeting that will extend several feet on all sides of the pool. You drain from the bottom and fill from the top.

Finally got the kit and after much rain this past week I did some tests. I had drained it about a foot and refilled (did this 3 times over the past couple of weeks waiting for the kit hoping to make a dent in the CYA without much luck). I first did the CYA test and it was right at 100 so I did the dilution test and it tested 40 x 2 = 80 so I redid the first test and it was at 100 again and ran out of reagent. The cl was at 0 so I added 12 gallons of bleach and it tested 22ppm Saturday night, I ran the pump all night. Last night it was at 10 ppm so I added 6 more gallons and it went to 25ppm, this morning 13.5. This was the FC test, the CC test was 1 and .5. I tried the other tests last night, TA at 150, CH at 450 and pH at 7.8. The water is still very cloudy this morning and I have cleaned the cartridge twice. I actually can't see the drains but the water seems more blue-ish. I thought I would keep the Cl at 25 until the water cleared and wondered how long you thought that might take. We have been under drought condition water usage so I can't drain it completely yet, but thought in the mean time I would run the sprinklers off of the pool water and add new water to the pool as that drains out some of the water each week. With the chlorine level so high and the cloudiness no one wants to swim yet but we are anxious.... any advice would be greatly appreciated.

• Watering with pool water, and putting fresh water in the pool sounds like a winner.
• You should lower your TA to 100 ppm or so, given your high CH. Read the muriatic acid page in my sig, and the Alkalinity page
• Make sure you BRUSH the pool completely while the chlorine is high, to expose any remaining algae.

OK.

We've seen several cases this spring of above-ground pools that take a long time (more than 1 weeks) to clear significantly. Usually, there's reason to suspect the big pump / little filter issue as the ultimate cause, but obviously we can't ask people to just go out and get a new filter and pump. The problem we have, at that point is that what we KNOW will work (a new optimal pump and filter combo) is off the table. And all the things are left fall into the "it might help, or it might not category".

So with that said, here are some other options:

1. Getting 2 new Unicel (or Filbur, or OEM) cartridges, and rotating them AND cleaning them properly will likely improve filtration all season, and may help clean up the current mess more quickly.

2. Using a clarifier and/or a liquid floc may help. If you go this route, be careful to follow instructions of the bottle. Products that have been reported to have helped include Bioguard Polysheen and Omni Super Floc Plus. Note that successful use of these products likely will require you to vacuum to waste.

3. Simply raising the chlorine, and then turning the pump off for 24 - 48 hours may allow the algae debris to settle and be vacuumed away.

But . . . no guarantees.

Good luck!

I was using the bleach calculator to figure out how many gallons to add to get the chlorine to 25ppm from where ever it was, usually somewhere between 8 and 10ppm when I tested each evening. I would add the allotted number of gallons, wait about 15 to 20 minutes for it to mix and then test but the numbers have been coming up short. I thought I might have made a mistake when I measured the pool, so I remeasured and I was off - 13000 instead of 17000 - but that told me that my Cl should have been much higher with the smaller volume, so I'm wondering if the bleach I'm getting is actually 6% as stated on the bottle (3/4 gal). I have been getting it at Aldi since that was the cheapest around right now. Is there a way to test the bleach concentration with the taylor kit to find out how strong bleach is? Or is there another test available to do that? I want to make sure I get the most bang for my buck since I am buying so much every day.

Here's a way to test the concentration of your bleach...I copied this from CarlD, one of the other mods, that had posted it a long time ago...
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Put ten liters of tap water ( That's 5 soda-bottles full) in a 5 gallon bucket.

Test that water for chlorine using the FAS-DPD test to get a chlorine baseline (you may have some).

Then I take a 1 ml eyedropper full of the LC or bleach I'm testing and put it in the bucket and mix it up.

(1 ml in 10 liters of water is the same as putting 1 gallon of LC in a 10,000 gallon pool -- it's 1/10,000th. )

I then measure the bucket with the FAS-DPD test just like pool water. Of course, subtract any chlorine you measured in the tap water.

I use a glass eyedropper so it will hold up. Pharmacies sell them.

Thanks so much for this. I tried it out on several brands and it worked perfectly. The Aldi bleach was 3.5 ppm, same as when I tested the pool after adding it. Kroger bleach was exactly 6 ppm. I will definitely be doing this test on one bottle before I go buying 20 of them.