Lower CYA and FC

Hello, I am new to maintaining my pool as previously relied on Leslies pool store, ha! After having my pool refilled i have since been doing lots of reading and watching utube videos to educate myself as much as possible. I have an Inground plaster pool that was drained due to high tds. Was refilled on 1.11.19 and I had the pool pro do the start up chemicals. I recently got myself a Taylor K-2006 complete test kit to take control of my pool. The readings from today
FC:15 ppm
CC: .5 ppm
Ph: 7.7
My CYA is high due to trichlor tabs pool pro added, I have since removed them. I know I need to add calcium chloride to bring up my CH. I will not be using the pool till June, so should I not worry about the FC being so high? I am assuming that it will lower down on its own through time. And for CYA it says by diluting your pool it can bring it down, but that is what I just did by draining my pool. Should I take any action or just keep an I on my Ph, TA, and CH for now? Thanks!


Mod Squad
May 3, 2014
Laughlin, NV
I am a little surprised by your low CH test result. Most water in Phoenix comes from high CH source water. I would suggest you check that test result. It is very low if correct. You will need to add calcium chloride, but first, check the test.
Welcome to the forum! :handwave:
Great job on getting a quality test kit!

100 is the limit of the CYA test, so you have to do a diluted test. Mix 50% pool water with 50% tap water. Use this mixed sample as your test water. Multiply the result by 2 for your CYA level.

I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Trouble Free Pool School book.
Thank you, I am in the process of reading it now.
I am a little surprised by your low CH test result. Most water in Phoenix comes from high CH source water. I would suggest you check that test result. It is very low if correct. You will need to add calcium chloride, but first, check the test.
I have tested the CH previously and it is 70. Would there be any other reason on why it could be so low?


Mod Squad
May 3, 2014
Laughlin, NV
What is your source of fill water? Have you reviewed the chemical analysis all water providers must publicize? Look for Hardness. It may be in Grains per Gallon.
You should get your CH to 250 ppm soon. But please be sure your test is correct.


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Before you add CH decide what you are going to do about your CYA test problem. A pool with CYA over 100 needs FC levels that are unmanageable long term. If your CYA is correct you need to drain or water exchange 50% or more of your water. No point in dumping CH into water you will be draining.


Bronze Supporter
Jul 10, 2018
Rancho Santa Margarita, CA
Grace, maybe its just me, but I question your CYA levels. You filled your pool after a complete draining on January 11th. That is only 19 days ago. Although, you don't have your pool water volume listed, for my pool to increase CYA from 0 - 100 ppm, I would have had to add 20 lbs or 324 oz of trichlor. That also would have increased chlorine by 165 ppm. All in 19 days.

Please list your equipment and pool water volume so the experts can fine tune their assistance.


TFP Expert
LifeTime Supporter
Jun 24, 2011
Long Beach, CA
Something is not adding up. There is no way tabs increased the CYA to 100 from a fresh fill. Was this a 100% fresh fill or was there some water left over?
There are two things to correct, the high CYA and low calcium level. The high CYA requires water to be drained and the low CH needs an addition of calcium. The first thing to do is get an accurate reading of the CYA using the process Marty explained above.
Thank you all for your input. My pool is 12,000 gallons with a Pentair intelliflo pool pump. My pool was completely drained and refilled with ground water. I took a sample of my pool water to Leslie's to get a 2nd opinion. The CH 200 and the CYA 50.

I retested my CH and I get 70. I retested my CYA and get 70. I watched videos on how to test the CH, I read the Taylor book that came wth my kit, and do not understand how Leslie's got 200.

I followed the directions precisely from the Taylor 2006 Complete kit.
1. Rinse and fill lrg comparator to 25ml mark.
2. Add 20 drops R-0010. Swirl to mix.
3. Add 5 drops R-0011L. Swirl to mix. If calcium hardness is present, sample will turn red.
4. Add R-0012 dropwise, swirling and counting after each drop until color changes from red to blue.
5. Multiply drops in step 4 by 10. Record as ppm calcium hardness as calcium carbonate.

I do these steps exactly and I get 7 drops of R-0012 when it changes from red to blue. 7 x 10 gives me 70 for CH.

I even did the test where it says if high CH is anticipated use 10ml sample, 10 drops R-0010, 3 drops R-0011L, and multiply drops in step 4 by 25. I get 3 drops x 25 gives me 75 CH.

I did the test also where I saw that if u have high chlorine put in a few drops of R007 before doing CH test.

My reagents have not expired. Is there any chance I could have faulty reagents? Anybody ever come across this?


Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

The whole point of having your own test kit is so that you can stay out of the pool store... They are notorious for having test errors.. You would be better off asking a drunk homeless man just to guess at what your readings should be, rather than going to a pool store. :)

Just trust you own tests...

Are you using the speed-stir? If not, it will make testing much easier and it will make you feel more comfortable with the tests.


Jim R.

Rancho Cost-a-Lotta

Silver Supporter
Apr 10, 2018
Rancho Cucamonga, CA
Take control of your pool and don't rely on pool store tests. Definitely get a Taylor Speedstir if you plan to do your own testing. It will make testing easier and you'll achieve more accurate and consistent results. Shop around and you should be able to pick one up for a $35 with free shipping.