TFP recommended levels versus Leslie's / Pinch a Penny recommended levels

[JoeN64]

As I am re-learning all of the water chemistry after years without a pool, I am happy to see all of the technology to assist with keeping track of tests and recommended amounts of the required agents to get water balanced. My question is this; If I use the Leslie's or Pinch a Penny app, or if I go in-store for a test, their recommended levels are somewhat different than the PoolMath app.

Pool store PoolMath My last test 6/8
FC 1.0 - 4.0 4.0 - 9.0 7.5
TA 80 - 120 50 - 90 95
pH 7.4 - 7.6 7.2 - 8.0 7.5
CYA 30 - 100 30 - 60 54
CH 200-400 250-650 240 - added 4 lb Hardness+

The recommended FC in PoolMath is so high that the other apps recommend I don't swim. My CC is 0. I added 1 bag of shock+ on Saturday afternoon because we got a ton of rain, which continued all weekend. Before shock FC was 1.8. I have a Nature2 express, which is about 3 weeks post install, so my goal is to lower the chorine and CYA. I have an inline chlorinator, which is currently turned off. The reason I went with a Nature2 is that I had a Vision system on my last pool (1999-2004) and loved the soft feel of the water. After reading a bunch on here over the last several days, maybe I shouldn't have added it, but none the less it's installed now.

Bottom line is I want to get it right and I am open to any suggestions from the experts, but I really need to understand why there are such discrepancies with some of the recommended levels between the 2 above.

Thank you!!

 

[Wobblerlorri]

The TFP method is different from pool store methods. We essentially rely on a balance between FC and CYA to sanitize our pools. The chlorine is buffered by the CYA, which is why we can have higher levels of chlorine and safely swim. Look at FC/CYA Levels for your range and stay about the middle of that.

Basically, you have to decide which method of sanitizing you want to follow. You can't mix and match them. You also have to either trust your own testing or go with the pool store. They aren't gonna match.

 

[IceShadow]

The pool industry (pool stores, manufacturers, equipment makers, etc.) don't take the FC/CYA relationship into account. Their recommendations are based on decades-old numbers that don't really get changed. You can follow them if you want, but people here are only going to give advice based on the TFP recommendations.

The higher TA recommendations are based on using chlorine tabs/pucks, which are acidic, and not a SWG / liquid chlorine, which are pH neutral. Without the acid, natural CO2 offgassing will slowly cause the pH to rise. Higher TA will cause quicker rise. 50ppm of TA is a good minimum to prevent sudden pH 'crashes' and offer a buffer without a lot of rise, but every pool is different. My sweet spot currently seems to be about 70ppm - it hasn't gone up all year, and in fact I recently added some Borax because it was hanging out around 7.1 / 7.2 pH.

Warranties on new equipment might require you to use their levels. You're kind of stuck there. Use their levels or void the warranty - if it were me, I'd use their levels until the warranty expired, then swap over. They're not so far out of wack that a little adjustment won't correct it.

 

[fields_g]

Formatted your table a little better

	Pool Store	PoolMath	My last test 6/8
FC	1.0 - 4.0	4.0 - 9.0	7.5
TA	80 - 120	50 - 90	95
pH	7.4 - 7.6	7.2 - 8.0	7.5
CYA	30 - 100	30 - 60	54
CH	200-400	250-650	240 - added 4 lb Hardness+

 

[Newdude]

One has evolved with the times and one relies on government guidelines from the 60s and 70s.

look no further than the current events if you’d like to see outdated government sanitation regulations in action. It’s no wonder we had to shutdown.

 

[mguzzy]

@Newdude ... yer such and alarmist!

If you really want to see the nuts and bolts discussions.. they are in the deepend., yikes. wear a life vest if you visit that forum.

Here ya go... this post if just from yesterday!
Recommended Free Chlorine Level - Old vs. New School?

 

[wireform]

Their recommendations are based on decades-old numbers that don't really get changed. In the end you'll buy products from them and that's all that matters.

 

[JoeN64]

Thank you guys!! I have the inline Chlorinator installed along with the Nature2 so I’m knocking it out of the park, lol. The tablets are stabilized and no doubt have raised my CYA. I do need to maintain levels for warranty purposes. I will go back and look at my contract to determine the requirements. I had no idea why there were differences so thank you for clarifying.