SWG Manufacturer vs. TFP Chem Recommendations

[capn7]

Greetings,

Apologies for the post as it seems this question has been asked by a dozen others, but I haven't seen other posts yet with numbers quite like my manufacturer is recommending.

Recently (past spring) added SWG. Looking to add borates (and understand it won't help me use less acid), but in researching that, it brought my attention to the rather wide chemical recommendation differences between TFP and SGS (SWG manu).


SGS
------
FC: 1-3
pH: 7.2-7.6
TA: 60-80
CYA: 30-50
CH: 200-400

TFP
------
FC: 3-5 or 4-6 (depending on where you look, & CYA)
pH: 7.6-7.8 (or 7.5-7.8, depending on where you look)
TA: 80-100
CYA: 70-80
CH: 350-450



Being in the Phoenix area, my CH is hovering around 900 currently, and not a whole lot I can do about that right now. SGS' manual does state, "The harder the water, the lower TA should be kept."

Can someone help me understand why such a disparity, and if I truly should scrap the manu and go with TFP recommendations? If it makes any difference, my SWG is oversized (based on pool volume) and runs at 50% during peak summer months and I had it at 25% prior to that, successfully maintaining ~2.0-3.0 FC.

 

[JoyfulNoise]

FC should always be maintained as a proportion of CYA. For manually dosed bleach pools, TFP recommends an FC/CYA ratio of 7.5%. For an SWG pool we recommend a 5% ratio. Also, for SWGs we recommend a higher CYA level because it allows the SWG to run less hours per day.

All manufacturers simply parrot APSP and industry standards based on old notions about FC being independent of CYA. Simply put, they are wrong. It may seem weird that a pool forum would tell an entire industry that they are bozo's, but that is the truth as the chemistry of CYA and FC is indisputable. The pool equipment industry chooses to ignore science. TFP does not. It's that simple.

 

[Divin Dave]

As for the CYA and FC, the pool industry does not recognize the FC/CYA relationship.
The reason TFP recommends what we do, is so that we keep our FC level to an extent to protect our pool from bacteria and ALSO to prevent algae.

This is not true in the Pool Industry. Pool industry only recommends FC level at 1-3 as protection against bacteria.
As protection from algea, the pool industry recommends to use algaecide and shock the pool once a week as protection from algae.

If TFP recomendations are followed, there is no need to spend lot of money on algaecide and shock, and then deal with the side effects of using them.

We recommend a slightly higher CYA because it preserves the FC a bit longer, which results in less run time needed to produce chlorine, which in the long run means your salt cell will last longer.

As for the TA, CH and pH, they all play a roll in what ultimately the CSI is. As JFN mentions, TFP belives in the science of what's going on in a pool and we base our recommendations on the science. Unfortunately, the pool industry is primarily interested in selling stuff. That's how they make their living. If their recommendations kept your pool trouble free they would be out of business.