Confusion about TFP recommended chemical levels.

rev29k

Well-known member
May 8, 2018
84
Tampa
Ok so this is my first post here on TFP and I would like to say it has been a great resource and I would like to thank everyone for their contributions.

My situation is that I have a recent pool build (past 6 months). After my initial startup, I continued using my builders pool tech to maintain the levels until I was acclimated to the process. He was using the standard APSP/NSPF Water Chemistry Guidelines/Parameters, which I continued using myself as well. I really don't have any problems maintaining my levels. Everything has been relatively easy so far.

My question for the group is what exactly are the reasons for the adjusted levels for SWG pools that I have seen suggested on TFP (the "TFP" levels)?

TFP SWG LevelsRegular Levels
CYA70-8030-50
FC4-62-4
TA60-8080-100
CH350-450200-400

For pH, that appears to be relatively the same for both charts, although I tend to try and keep it near the middle, around 7.5 or 7.6, so I'm not sure if that needs addressed at all either.

Would someone be able to explain the REASON for the recommended differences on TFP for these levels? That is what I am really trying to figure out. I am not opposed to alternate ways of thinking, but would like to understand the rationale behind those numbers.

TIA for any help you guys! Like I said, I really enjoy this forum and have learned so much on my own by using it as a resource. But I'm just unable to find any detailed explanation for these levels.

Thanks!
Sean
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
14,579
Evans, Georgia
Hey there Sean, welcome to the Forums :)

We have learned over time and thousands of pools in various climates that having the CYA a skosh higher helps the SWG device chug along at its slow pace with the least amount of chlorine loss. The less chlorine the SWG device has to make, the longer it stays functioning. Sure you can replace cells more often but why? Why not save those bucks for something more fun like more pool toys? :party:

With plaster pools sometimes pool owners find the CSI important if they live with challenging water or climate situations. SO adjusting levels are fine as long as they strive to maintain a neutral or slightly negative (usually) CSI reading. Our PoolMath app or webpage can help show the variables and let you play with the numbers.

Being in FL with your frequent rains and often necessary drains to lower high water, you tend to have to readjust calcium and CYA, right? Folks out west with high calcium, high evaporation and expensive water *wish* they had your rains. Everyone needs to work with what they have and keep things "balanced" and the TFP guidelines help you do that.

Maddie :flower:
 

rev29k

Well-known member
May 8, 2018
84
Tampa
Thanks Maddie. I realize it's winter right now, so my chlorine loss is probably going to go up. But I've literally been teetering on the lowest possible output for my SWG (anywhere from 6-10%), with my pump only running for 10 hours a day at roughly 1600rpm/30gpm. I guess I will have to wait until summer to really see how it's going to be affected. :) But for now, as far as CYA and chlorine loss goes, it's been negligible. And I can't run my SWG any lower than 6% or my Acid Dispenser will shut down.

I have been checking my CSI and it's usually slightly negative, like -.06. So I have been keeping that in line as well.

So you are thinking that these higher levels will help more in the summer given all of the fresh water that is constantly introduced? To act as sort of another level of "buffering" to fight against all of the extra rain?

Are there any other reasons for the different levels?
 

Flying Tivo

Well-known member
Jan 24, 2017
1,889
Monterrey, NL, Mexico
Remember a SWG cell is either on/off. The % you dial in is just the amount of time its in the ON position during a 60 min cycle. I rather think of runtime in $/kwh, and that depends on your location. If its a cheap Kw, then you can run like you are, but if its expensive, i rather have at 100% for the least amount of time.
 

ping

TFP Expert
LifeTime Supporter
Jun 24, 2011
3,131
Long Beach, CA
The difference with the chlorine levels is due to the pool industry is stuck in the olden days and have not come up to speed on the use of CYA. There is much research done by past and present members that have proven the FC/CYA relationship and you could read all about it if you search for it. Slowly but surely some in the pool industry are coming up to speed, but it is a very slow process for them. There are plenty of SWG manufactures that say to use 80ppm of CYA.

The TA difference will allow you to use less acid to control the pH. With a SWG and a TA of 100 the pH will most likely rise very fast which will increase the use of acid. When the TA drops in the 60/80 range the pH rise will slow down.

The CH level doesn't have much difference, but you want to make sure you have enough since you live in Florida. If you find that you need to add CH every now and then, bring it up to the upper recommended range and let it drop to the lower end before adding any.

Just keep an eye on the CSI since you do have a plaster pool and not get too picky about any one level. I have to adjust these levels due to the CH in my pool being over 700 right now. I have no issues with the water balance, I just adjust the levels slightly to keep the CSI in line to prevent scaling.
 

markayash

Gold Supporter
Mar 21, 2016
2,514
Atlanta Ga
Circupool also list higher CYA


Free Available Chlorine 1.0 - 3.0 ppm
Salinity 3000 - 4500 ppm
pH 7.2 - 7.8
Total Alkalinity 80 - 120 ppm
Calcium Hardness 200 - 400 ppm
Stabilizer (Cyanuric Acid) 60 - 80