Switching from Frog to SWCG

[P00LNerd]

Received my RJ-45+, and reading the manual now. It calls out FC target = 1.0 - 3.0 ppm for CYA = 30 - 50, or roughly 5% average. Pool Math tells me 5.0 - 10.0 for CYA = 60, or roughly 12.5% average, 2.5x higher than CircuPool. Even the bottom of the range in pool math = 5/60 = 8.3%, whereas bottom of range from Circupool = 1/50 = 2%.

What am I missing?

edit: Further reading in the same manual, I find what I believe to be their reasoning: "This form of chlorine works quickly in the pipe, leaving only a mild residual in the pool. In addition, the Electrolytic Cell continuously “shocks” the incoming water- burning off any oils, organic matter, or other particles that need to be oxidized." So, much higher FC levels in the plumbing, outlet side of RJ cell, but lower FC measured in the pool. Conversely, when I'm adding liquid chlorine, it's just that level everywhere.

 

[PoolStored]

Follow this, always...Link-->FC/CYA Levels

 

[P00LNerd]

Follow this, always...Link-->FC/CYA Levels

I understand you guys like to follow that. I'm just trying to understand why. CircuPool manual says to target FC = 1.0 - 3.0 ppm for CYA = 30 - 50 ppm, but Pool Math says target 5 - 7, with absolute min 3.0 ppm.

Put otherwise, if 1.0 - 3.0 ppm is insufficient, then CircuPool is really setting their own equipment up for bad reviews and failure. It just doesn't make sense.

 

[PoolStored]

Pool Water Chemistry

This thread presents my findings so far on pool water chemistry including the following: More Accurate Calcite Saturation Index (CSI) to replace Langelier Saturation Index (LSI) Calculation of ppm HOCl (disinfecting chlorine) at various levels of Total Free Chlorine (FC) and Cyanuric Acid (CYA)...

www.troublefreepool.com

 

[Newdude]

I'm just trying to understand why. CircuPool manual says to target FC = 1.0 - 3.0 ppm for CYA = 30 - 50 ppm

The industry doesn't follow the well proven science that CYA binds the active HOCL content of chlorine. In short, they treat pool water like tap water with CYA and FC being two independent values. Tap water with 1 to 3 FC and 0 CYA is harsh, so in that regard, they are correct. But raising the CYA content also raises the FC needed to sanitize at the same level.

Going full circle, they misapply the science of metals for disinfectants also. It works in a closed system that is never exposed to the sun, bathers or the environment. Open the lid on the 'collection tank' and throw some swimmers in there along with environmental debris and the non contact killer copper/silver no longer do what they previously did.

Changing the equation of tap water changes the end results.

 

[P00LNerd]

Pool Water Chemistry

This thread presents my findings so far on pool water chemistry including the following: More Accurate Calcite Saturation Index (CSI) to replace Langelier Saturation Index (LSI) Calculation of ppm HOCl (disinfecting chlorine) at various levels of Total Free Chlorine (FC) and Cyanuric Acid (CYA)...

www.troublefreepool.com

Dang. That thread should just be the landing page for this whole site and forum. I wish I knew that existed a few weeks back, as it answers most of the questions I've had. Really, you guys need to just direct everyone to that one thread!

Going full circle, they misapply the science of metals for disinfectants also. It works in a closed system that is never exposed to the sun, bathers or the environment. Open the lid on the 'collection tank' and throw some swimmers in there along with environmental debris and the non contact killer copper/silver no longer do what they previously did.

... and, I suspect that most of the recommendations for lower FC levels are made under the assumption the user is running Cu-based algae blockers. Even the first post in @chem geek 's thread shows the order of magnitude gap between what is recommended by WHO and his best guess as to what is required to stop algae growth. The gospel of this site is "nothing but chlorine", which I think sets the requirement for higher FC levels, than if one were loading algae block into the water.

Not sure which is better or right/wrong, just two different mentalities. One seems to have higher potential for staining, the other for corrosion, depending on how all other levels are managed.

 

[P00LNerd]

I came across this in the CircuPool manual:

NOTE: When using a Variable-Speed or Multi-Speed pump on a low speed setting, or for general circumstances where flow is less-than-adequate, the cell must be inverted in order to ensure adequate flow & efficient chlorine production.

How many of you guys are running yours inverted? With all my plumbing slammed down against the slab, it'd be much easier to plumb all of this up in non-inverted configuration. If I go inverted, I need to elbow up to a higher plane to fit the RJ cell.

 

[PoolStored]

Dang. That thread should just be the landing page for this whole site and forum. I wish I knew that existed a few weeks back, as it answers most of the questions I've had. Really, you guys need to just direct everyone to that one thread!

It is a bit much for the average pool owner that arrives here. For those that nerd out on the chemistry, it is appropriate.

The conclusions of the thread are embedded in pool school and FC/CYA Levels.

How many of you guys are running yours inverted?

You should run the cell inverted.

 

[TinFoilHat]

Yes, the inverted cell will ensure it still generates at lower speeds. Just keep in mind that at some point of low speed the flow switch will turn the cell off. At that point you want to add 200 rpm at a time to the low speed until that speed is fast enough to satisfy the flow switch.

 

[P00LNerd]

Okay, I managed to fit it all onto the existing pad, and even re-use these almost-new Jandy 3-way and check valves, by just grabbing the port OD's with 2" fittings. Yeah, it's a little bit of a goofy 2" + 1-1/2" mash-up, but it all works out okay.

I didn't bother filling in every little straight section of pipe, or the pump and filter (both to right of heater), that's just wasted time modeling and mating parts, but I think it should be obvious to most what's going on. Let me know if you spot any problems:



This basically copies the layout straight out of the manual, albeit a bit more folded onto itself, to fit the available space.

... and before anyone asks me about the goofy angle on the union coming out of the heater, which is tilted up... we have the pool company installers to thank for that. Rather than just using a pair of elbows to jog up, they tried jamming the Frog onto that port at a stupid angle, since the Frog inlet port was maybe 3/8" higher than the heater input port. So, I just come off that with an elbow, which allows me to "clock" out the angle. Only side effect is that my 3-way Jandy has to sit at same angle, to mate up with the bypass tee.

 

[P00LNerd]

Figured this might help:

 

[proavia]

Place the cell hump down.

Follow TFP guidelines.

Minimize over-thinking.

For a true heater bypass, you need a check valve in the heater outlet line - to the left of the "T" in the line below the Jandy 3-way valve.

 

[P00LNerd]

Place the cell hump down.

I did.

Follow TFP guidelines.

I think I did?

Minimize over-thinking.

There is no such thing as over-thinking. There's only thinking of everything, or not.

For a true heater bypass, you need a check valve in the heater outlet line - to the left of the "T" in the line below the Jandy 3-way valve.

I saw this in your diagram, and liked your logic there, the check valve totally blocks off the heater when there's no forward pressure to open it. But then I saw that the RJ-45+ manual disagreed with this, instead placing it where I have it shown:



I guess their thinking is to ensure it can never auto-siphon back thru heater input, if valve is in partly-closed state? Not really sure.

If no reason to follow CircuPool manual, I'll do it your way.

 

[PoolStored]

I think I did?

You have used a foam mat, when we have recommended a hard surface mount.

 

[proavia]

If no reason to follow CircuPool manual, I'll do it your way.

The check valve needs to be in the outlet line of the heater as indicated earlier. It shows that way in the TFP heater bypass article as well.

I guess their thinking is to ensure it can never auto-siphon back thru heater input, if valve is in partly-closed state? Not really sure.

What "it"?
If the pump is off, the SWG is off. No chance of the powered/generating SWG backflowing into the heater.
You are attempting to isolate the heater from the rest of the plumbing in case you need to remove the heater from the circulation system (heater maintenance, heater leak, water treatment that may harm the heater, etc.).

There is no such thing as over-thinking. There's only thinking of everything, or not.

Sometimes "not" works better.
Much less stressful.
Might be better sometimes to trust but verify.
In this case, someone has done the thinking for you/us. And it's worked well in 1000's of pools prior to yours.

 

[P00LNerd]

You have used a foam mat, when we have recommended a hard surface mount.

No, I didn't. That's a very hard rubber matt designed for tiling factory floors used by forklifts and other heavy equipment, nearly as hard as the plastic base of the heat pump chassis itself. It won't compress at all under the ~150 lb. weight of this heat pump, it might as well be tile, but with better anti-skid properties.

But in the end, with only minor fudging of the pipe angles, I think I can just skip the mat. I need to drop the plumbing 3/16" between Jandy 3-way and the heater inlet. The center/center distance is 20 inches, and there are 4 weld socket joints in-between. It amounts to a 1.1° angle, easily within the slop of PVC plumbing glue-ups.

The check valve needs to be in the outlet line of the heater as indicated earlier. It shows that way in the TFP heater bypass article as well.

Got it. No problem to move it. I wonder why CircuPool doesn't recommend that way.

What "it"?

The water.

If the pump is off, the SWG is off. No chance of the powered/generating SWG backflowing into the heater.

Was just trying to guess at CircuPool's reasoning for their recommended hookup being different than yours. My heater manual agrees with your recommendation, just weird that CircuPool went a different route with their recommended connections.

Might be better sometimes to trust but verify.

That's exactly what I'm doing, as in check-valve above, as in super-high chlorine levels, as in ditching the Frog. I'm following all of those suggestions, but also asking reasoning behind them, so I can understand the trade-offs. Please don't take my asking "why" as anything other than just trying to understand the reasoning.

In this case, someone has done the thinking for you/us. And it's worked well in 1000's of pools prior to yours.

Yep. And the traditional method the TFP founders were walking away from at the time, were used in maybe millions of pools prior to theirs! Even when you suspect a new method is better, it's always good to understand one's reasoning, when their recommendations fly in the face of tradition. Often you will find they were solving a problem created by circumstances different than your own.

 

[P00LNerd]

Fixed the check valve location:

 

[P00LNerd]

Loaded some salt in over the last week, and the last two tests have me at 3400, then 3200 ppm. So, close to target.

But now everyone going into the pool is whining it tastes like salt, especially the kids. I really wasn’t expecting that, based on everything I’ve read, about the salinity being so low.

Yes, I can definitely taste it, but not so much that it’s offensive to me. I am hoping what they’re responding to is just the change, and that they’ll soon get over it. Otherwise, this has been an expensive experiment.

 

[Turbo1Ton]

I run mine right around that level also, and I can taste it slightly. It is definitely not offensive to me. I'm not sure my kids have ever said anything, but ours has been salt from day 1 (or 30 rather).

I'm guessing it is the change that they are complaining about and in short time, they will not even give it a second thought.

--Jeff

 

[sande005]

I've been the only one to notice the taste at 3400, but we haven't had a wide variety of users, either. I joke about it, but it really is significant how much better I can float! Literally no air mattress needed! It's become one of the favorite things to do - just be a dead body, lying face up on the surface of the water, watching planes and clouds go by overhead.