New pool/homeowner with high CYA

Jump to latest Follow Reply
P

PostDingus

Member
May 12, 2021
8
Northern New Jersey
We just bought our first house that came with our first pool--about 10,000 gallon above ground. The previous owners (who did hack DIY jobs in other areas of the house) winterized it and we are preparing to open it up. They left zero evidence of chemicals so I do not know what they used.

I bought a test kit (Taylor K2005) and when it arrived I read the booklet cover-to-cover then pulled a sample. So far I've got:

FC: 10ppm
TC: 15ppm
pH: somewhere way below 6.8--20 drops of base demand did not change the color
CYA: 200ppm

For what it's worth, the level is about 8 inches below the skimmer, but regardless, that seems very high. Could there be something skewing my result or am I safe to conclude that my first course of action should be to drain and refill?

This forum is fantastic, by the way! Thank you for the advice!
 
Hellooooo Dingus, Yes, a CYA level of 200 is horribly high. But I am curious to be sure that you did the CYA test correctly to obtain that result?
Did you mix equal parts of pool water and tap water, then use that to test the CYA level, doubling the results??

My other concern is that the K-2005 test kit doesn't contain an FAS-DPD test kit, so you have no way of testing high FC levels nor Combined Chloramines. You can obtain the missing FAS-DPD test at www.tftestkits.net .

With liner pools you can drain only so much, as too much drained can alter the fit of the liner. I would suggest draining by only 3/4 then filling again right off. Let it mix well and then retest the CYA.

How do you plan to chlorinate the pool? Have you read our suggestions?
www.troublefreepool.com

How to Chlorinate Your Pool

Before chlorinating your pool, you should know these simple tips. Learn the best way to add chlorine to your pool.
www.troublefreepool.com www.troublefreepool.com

When the pool is filled and you have an FAS-DPD test also please rerun the test and tell us-
FC
CC
pH
TA
CH
CYA

Let us know how its going-
Maddie :flower:
 
  • Like
Reactions: needsajet
Thank you! Yes, that is correct. I first did the CYA test in the normal way. The water essentially looked like milk. Then upon diluting with 1/2 tap water, I got it about to the 100 line (actually still lower, so the reading is likely higher than 200ppm). I also found an empty bottle of "4 in one" chlorine pucks and a bottle of algicide which I think validates my suspicion.

My plan is to use straight liquid chlorine moving forward.

Ok then, draining away! I'll post up my new readings once I start to balance everything.
 
So, if you did those tests with the water 8" below the skimmer, then your CYA was actually lower than your reading. By adding the missing water to top up your pool, you would be diluting the CYA and thus lowering it some. Don't do it though, because, you're still way high regardless. I would drain at least half and then fill it back up and take all new reading.

Definitely pick up the FAS-DPD portion of the chlorine test which comes in the K2006. That's the only difference between the K2006 (which we recommend) and the K2005. You can buy that part separately though which will, in effect, make your kit the K2006.
 
I did the same thing and bought the K2005. Just buy the Taylor 1515A kit for about $30. If you move things around a little bit, you can fit the powder and the dropper bottle.
 
PostDingus said:
Thank you! Yes, that is correct. I first did the CYA test in the normal way. The water essentially looked like milk. Then upon diluting with 1/2 tap water, I got it about to the 100 line (actually still lower, so the reading is likely higher than 200ppm). I also found an empty bottle of "4 in one" chlorine pucks and a bottle of algicide which I think validates my suspicion.

My plan is to use straight liquid chlorine moving forward.

Ok then, draining away! I'll post up my new readings once I start to balance everything.
Click to expand...
Try a dilution of 2 parts tap water to 1 part pool water and do the CYA test on that. Multiply result by 3. You want at least an idea of how much CYA is in there so you know how much water you need to exchange.
 
Hi everyone, thank you for the advice. I have the appropriate test on order.

I dumped the water down to about 1/3 and refilled. Now I'm showing about 90ppm CYA, so finally in the ballpark (though still high). Since then I've done about 6 backwashes (pool was FILTHY) so I imagine I'm a little bit lower now. Turns out the pool is about 5,000 gallons (18x12 oval), not 10,000 I previously mentioned. pH was very low so I added three pounds of sodium carbonate and got that in check. I got some 10% liquid chlorine ($3/gallon yes!) and added 1.5 gallons to shock and kill the algae. TA last I checked I think was 120.

I just checked, and it looks like I'm at 30ppm FC. Will let that stew overnight and see what we look like in the morning! Thank you again!
 
You will need to do a proper SLAM
SLAM Process

You can't just raise the FC one time and call it done.

FC/CYA Levels
Use the chart to identify your correct SLAM level based on your new CYA level and then hold it there until you pass the exit criteria - it may well take several days.

Good luck!
 
Get it up to 36 ppm FC and keep it there for several days, per SLAM Process

It won't take so much chlorine to keep it up at 36 ppm, at least not compared with the amount to get it up to 36. Brush often, twice a day at first, once a day as you continue the SLAM. Anything that goes in the pool should be in there (e.g. cleaner, brush, scoop, toys). Also, peer around inside the skimmer to see if any algae can be brushed in there. It will take the filter a fair few days to clear out the white / light brown "dust" floating in the water (dead algae "carcasses"). Run your pump 24/7 (hastens the SLAM)
 
Hi Everyone,

Thank you for the advice. I got the TFP FAS-DPD test kit (can't believe I waited so long! I LOVE this method!). It's been a few months since I SLAMmed but I've got my system down and some beautiful water. This is easy!

Typical twice-weekly readings are around:

FC: 2-4
CC: 0-0.5 (if 0.5, up FC to about 5ppm and that fixes it. We have a low bather load)
CYA: 50
TA: 110
pH: 7.8-8.0

My system is to add 6 ounces of liquid chlorine every other or third day. My pH tends to creep up when adding water (tap pH is about 8.0) or after a rainfall, so I sometimes add about 8oz of muriatic acid to bring it down to 7.4.

Thank you again to this wonderful community.
 
  • Like
Reactions: BenB

Enjoying this content?

Support TFP with a donation.

Give Support
Good job clearing the water, but please be very careful as your FC levels are still very low for manual dosing, especially if you're only adding every 2-3 days. With the right amount of CYA in your water there is no need to worry about having 'too much chlorine'.

Please take another look at the FC/CYA Levels and adjust your dosing so that at no point does your FC ever go below the low end of your target range. If that means adding to reach 4-5ppm above the indicated number such that 2-3 days later you're then getting to the low-end, then that's what you should do.

Are your test results that you posted before or after dosing?
 
Ah, thank you for the heads up; I hadn't looked at that chart in awhile and mistakenly recall 4-5 being appropriate for 50ppm CYA. Will up to to 6-8ppm moving forward. Test results are posted before dosing.

I had a CYA problem at the start of the season from the previous owners of our house, so had been keeping FC at around 15 while I did a few dump/refill cycles. Thank you again for the caution.
 
PostDingus said:
Ah, thank you for the heads up; I hadn't looked at that chart in awhile and mistakenly recall 4-5 being appropriate for 50ppm CYA. Will up to to 6-8ppm moving forward. Test results are posted before dosing.

I had a CYA problem at the start of the season from the previous owners of our house, so had been keeping FC at around 15 while I did a few dump/refill cycles. Thank you again for the caution.
Click to expand...
With a CYA of 200, FC of 6-8 will not do much for you.

Even if you dump half the water and get CYA down to 100 (still too high, but gets you on the charts), the target FC is 11-13.

If needed, the chart is in my signature.
 
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply