4 year old pool but recent subscriber trying to learn the science and fix CYA

[WilliamHTX]

Hi. We built a new house and new pool in 2020, first pool I have had ever. Recently started using TFP calculator and trying to understand the chemistry to the best I can. I have been maintaining it myself thing for around 3 years and honestly not had any serious issues other than the occasional greenish or yellowish patch’s that start to slightly show up in summer. They go away with a good brushing. We get a lot of pine needle and leave trash due to neighbors. It was my investigation on the occasional algae that led me to do a water guru which I have been happy with and start reading her and learning that with my cynuric so high that my chlorine at rhe ranges the Guru or Leslie’s advises, is probably ineffective chlorination.

For the last 6 months I have been using liquid chlorine or some Leslie power powder plus which is 70% cal hypo.

From this pool link though you can see my cynuric goes down and the for some reason back up. I have not introduced any tablets like used to. I have tried draining a couple of feet of water and adding from the hose. I have also tried rhe BioActive product recently and it dropped down to the 90 ish range but then went back up to 120 this week when I added 16 ounces of the Leslie’s cal Hypo. There should be no cynuric coming in so any idea how it’s going up - unless the Leslie’s cal hypo somehow is lying about not having cynuric acid.

PoolMath Logs

 

[Newdude]

Hey William and belated Welcome !!!

We don't trust the Guru unless you're confirming it at times with a Taylor based drop kit. Even then, we only trust the Taylor, and your Guru just agrees with us.

 

[WilliamHTX]

I’m confirmed the guru with Leslie’s trips and a mail in water test to the Guru guys. Is it the Cyn you wouldn’t trust? I have a Taylor k1515A I bought recently - all the other I ever had I was too terrible at guessing color shifts to feel like I was reliable enough at the guests to add chemicals.

Taylor K-1515-A Drop Test Kit Fas-Dpd Pool Chlorine .​

 

[Newdude]

The 1515 is GREAT for FC/CC and what we use, repackaged in another kit.

Leslie's and Guru/2 have simply proven unreliable to trust either. We don't have a ton of members trying the Guru's but the folks led astray by Leslie's is in the many thousands since 2007 here. You're seeing it first hand, the CYA should stay rock solid without adding more or a leak causing constant refilling.

 

[Donldson]

Look at the way your TA and CH numbers are bouncing around similarly to the CYA numbers.

That's a dead giveaway that the testing is unreliable. Most likely your CYA never even dropped from the Bioactive, it's proven to be ineffective in most cases.

 

[dereksanders]

Test Kits Compared

 

[casiokid]

Welcome to the forum!

As a TFP advocate for a while and a WaterGuru owner, I can tell you that the Waterguru is simply too unreliable for any decent results. It’s great for when you go on vacation and need to keep an eye on things, but it is by no means an “every day driver.” The results are all over the map.

Your CYA cannot go up and down on a regular basis as you’re seeing. CYA can ONLY go up when you add CYA.

Get yourself a Taylor-K2006C, test daily, and stay away from Leslie’s!

 

[WilliamHTX]

I’m very test kit challenged.

 

[proavia]

Look into getting a TF-Pro (includes stirring device) or a TF-100 test kit.
Between the WaterGuru and Leslies, you are seeing inaccurate and inconsistent test results.

The TF test kits are more aimed at the residential pool owner. They contain more reagents for the tests we do most often.

Using a drop based test kit is pretty easy - just take one test at a time.
We are here to help walk you thru it. There are even YouTube videos showing how to do them.

 

[WilliamHTX]

Ordered the pro kit with stir stick. So yesterday’s Leslie’s test at least confirmed the Guru’s mysterious cyrnuric acid numbers were wronf, unless Leslie’s were. Below is actually my August, September and December Leslie’s tests were I was trying to confirm Guru numbers. Like I said I’ve never had one of those disaster experiences with it turning green etc just the yellow green algae areas on the sides on some weeks I summer. Started doing it myself thing vs a pool guy the first couple years because with the line trees in neighbors and sweetgum trees, I am netting it, cleaning filter socks and brushing it 5 days a week and always before weekend swimming, so figured why pay a pool guy if I was out there anyway. Not to dismiss a good pool professional’s worth by with the huge pines etc and Houston weather I’m out there ….

Here are some Leslie’s numbers from August, Sept and December. If the latest is to believed my two small draining sessions (about 2 feet total over two sessions) and maybe the bioactive, has the Cya down.

My Alkalinity was my concern these last few months and getting my cya down once I started use the TFP calculator because it seemed like high CYA and the TFT guidance meant I was having to add lots of liquid chlorine and shock to actually have rhe sanitary levels be effective or not have rhe occasional algae. I have only been using liquid chlorine from the hardware store, and the little bit of Leslie power powder plus - cal hypo for about 6 mos now.

Anyway I will await the TFF Pro 100 but seems like I should address the alkalinity, the pool math calculator says

 

[Parac]

Wait until you can test with your own kit before making any adjustments. Besides the questionable accuracy of pool store tests, they report adjusted alkalinity. You need the non adjusted number for pool math.

 

[WilliamHTX]

So first attempts with new TFT Pro kit. Got Cya of 80. This is compared to water guru today saying 104. Yesterday water guru said 90 on CYA so not sure how that could at all be true since I am not adding Cya products.

TFT 100 pro test showed FC of 4. Taylor Fas DPD test showed 4.5 on a 10ml sample. The kits seem to be the same reagents but the TFT Pro says use 1 scoop of R0870 to start and the Taylor 1515A uses 2 scoops.

These are not much off at all from Water Guru’s 3.9 FC. On TA the TFT Pro measured 80 - that’s assuming this picture below is “red” per the instructions. That’s 8 drops to that color. The guru was saying 60 today.

Calcium hardness, 450 with the TFT Pro and 386 with Guru.

 

[Griswald]

That's not done, it turns a Barbie pink and then won't get any more pink.

 

[sande005]

Check the amount of water to use for the DPD test between the two kits - some are written for 10 ml of water (1 scoop), some for 25 ml (2scoops). The larger is more accurate, but the lesser is by far close enough for any of our needs, so you might as well save on the amount of reagents you use.
CYA can be the hardest to discern when the dot disappears. If above a line, round the reading up to the next higher.