New indoor pool chemistry advice?

[mknauss]

'Shock' is never needed. You test and manage your FC using your SWCG or liquid chlorine. If you do not pass a Overnight Chlorine Loss Test, you follow the SLAM Process. And never use MPS ---

 

[ajw22]

OK my builder had the spillover running on a 24/7 schedule with 100% of the water going over. I've deleted the schedule and turned off the spillover. I am still spilling over now but you can barely see it - the valve minimum was set to a slight angle so it doesn't completely close off the spa returns. I can see if this makes enough of a difference before doing something more complicated. Rather than two valves for (spa | pool) and (spa jet | spa return) I have (jet | return) and (pool return | spa return) which I think is non-standard. I could replumb (there are some other weird things to fix) but it seems to work.

Post pics of your equipment pad an valves. I think you would just need to reset the valve so it completely closes the spa return when in pool mode.

One question I still had was on the shock - is the MPS non-chlorine shock the right stuff for an indoor setting? Something about sulfates? Maybe OK if I only need it once in a while? I am glad to hear I don't need it just yet but I have three kids so I know "events" are going happen whether I want them to or not...

If you follow the FC/CYA Levels there is no reason to regularly shock the pool. Normal levels of FC can handle any events from swimmers. You can superchlorinate up to SLAM FC levels if necessary.

MPS can help get rid of the CC's that accumulate since you don't have a UV source to burn them off. You can wait to see if your CC's are increasing in your testing or if you are getting an increased chlorine smell around the pool from the CC's.

In an indoor pool, there is little to no UV light getting to the pool. Outdoor UV light acts as both a supplemental form of oxidation for CCs as well as a source for creating powerful hydroxyl radicals that also help to eliminate CCs. Depending on your bather load and the level of CCs that accumulate, you may need a supplemental form of oxidation. Potassium monopersulfate (MPS) can help with this but two things will occur - you will build up sulfates in your water over time requiring you to exchange out water more frequently AND the MPS will interfere with your FC testing (DPD-FAS testing). If you use MPS, then you should order their additional MPS Interference Removal Kit .

Let's see what @JoyfulNoise can add to this.

CC - Further Reading

www.troublefreepool.com

 

[JoyfulNoise]

I would add this - you are probably one of the few pool owners that I would suggest a UV system for (not Ozone because you're indoors and ozone is bad for your respiratory health). A high output UV sanitizer can help as a supplemental form of oxidation that can better breakdown bather waste into less reactive components. Superchlorination can do the same thing BUT you will begin to generate higher and higher levels of persistent CC's that will not go away over time. Eventually you'll get that "nasty chlorine pool smell" that everyone hates. UV will help to lower the burden on your chlorine source and oxidize harder to remove CCs.

I would stay away from MPS as much as possible and only consider using it if there was some extreme bather event like a pool party. The sulfates will wreck your SWG plates over time and attack any metal components you might have in the water like ladders or hand rails. It will also make testing a lot more complicated as you'll need to use a special deoxidizer reagent to remove the MPS interference from the FAS-DPD test.

Finally, you ABSOLUTELY NEED CYA in your pool. Just because it's an indoor pool doesn't mean you should not have stabilizer. The nice part is you can get away with just using the minimal amount of CYA, 30ppm. That's about the lowest level one can easily test for. Keeping your pool at a CYA of 30ppm and an FC between 2-3ppm will make the water much less harsh on bathers and could help to lower persistent CC formation. The chemistry is a bit technical but basically when you have a powerful oxidizer in the water like chlorine with nothing to moderate the amount of active chlorine formed, reaction rates for ALL oxidation reactions increase which means the nastier chemical compounds (trihalomethane and disinfection by-products) can form a lot more rapidly. This is one reason why municipal water suppliers try to remove, filter and oxidize as much "junk" in potable water before adding the lowest possible dose of chlorine to it (which happens as the last step before water leaves the plant and enters the distribution system) - if you chlorinated water as the first step in the process, you would create such nasty stew of chemicals that it would become undrinkable no matter how much you tried to filter it.

 

[crustacean]

Just for you to know that water turnover is a meaningless myth.

Your pool is sanitized by the chlorine in the water.

How little or how much your water changes a day makes no difference to the quality of your pool water. And running the pump enough to meet your SWG chlorine demand is sufficient for filtering the water.

Determine Pump Run Time

To figure out how many hours you need to run your pump, you need to know how fast your pump works. You can find this here.

www.troublefreepool.com

Thanks. That all makes sense. Sounds like I could run the SWG at a higher percentage for a shorter time and then reduce or eliminate the flow. I'm been setting it to 3-8% daily based on usage so we definitely don't need much.

 

[mknauss]

Heater time drives how long you need to run the pump each day.

 

[crustacean]

When I wrote "for me at least, it's the better choice" I was referring to the sensors. Here's the rub. The chlorine dosing of the IntelliChem relies on technology that doesn't work well, or at all, with the CYA level I run my pool at. At CYA20-30 you might have better luck. And as you point out, the pH sensing requires calibration. No thanks. I don't think it's prudent to trust consumer electronics for the testing and dosing of a residential pool. Which means I'd want to back up the IntelliChem with my own testing. Say, once a week to be safe. Well, I only test my pool once a week now, so all the IntelliChem would provide me is one more thing to keep running. My pH is very stable with the IpH, so I don't have to fiddle around much with the IpH's settings. Same for my SWG. Testing is easy and reliable. So is the IpH/IntelliChlor combo. Together they eliminate all the maintenance I want eliminated. If Pentair offered me an IntelliChem for free, I'd pass. Maybe it works great, but I just don't have a use for it.

We've got another thread going where we're discussing the annual maintenance of IntellipH. I haven't touched mine for almost four years, others talk about two or three. Yes, Pentair recommends once a year, and that's probably prudent, but they're capable, at least for some of us, of going longer. The recommended maintenance is just the tube, not the motor. There's another part, too, that might need some love. It's called the "duck bill." It's a component of the injector. I haven't dealt with that yet, either. I don't actually know its replacement recommendation. But I'll probably just swap it out soon, just to play it safe.

I've burned my deck with muriatic. My arms. I've breathed it in. No thanks. (I need constant supervision!) Whatever maintenance my IpH needs, no problem, it's worth it.

I wouldn't want my IntellipH indoors. It does have a venting system, so it might be OK, but I'd be a little leery of that. Is your equipment pad indoors? If so, how close is the SWG to an outside wall? I don't know if there is a limit, but I imagine you could place the IpH at least 10' away from the pad, probably more. But yah, that's something to think through. And when an IpH is present, you have to plug the IntelliChlor into the IpH controller, not the IntelliCenter, so there's that. There would be some cable lengths to figure out.

This sounds exactly like my situation. I seem to need a little all the time, and I don't want to spill or have the acid readily accessible indoors. Handling it once a month would make it more feasible to store elsewhere.

My equipment is all indoors - I asked about doing it outdoors but if the power goes out while it's 0 degrees outside there'd be a disaster. My mechanical room already has quite a few vents (two gas heaters, HRV in/out, and exhaust fan for negative pressure vs. the house) so one more can't hurt. I do still have a spare corner so maybe I could keep it away from everything else in case of accidental spills.

 

[JoyfulNoise]

In case you were wondering, you could get something like this from Pentair -

BioShield® UV System

Pentair BioShield® UV System harnesses ultraviolet light to reduce harmful chloramines and provide a more enjoyable pool experience.

www.pentair.com

Their instruction manual details a "by-pass configuration" in the plumbing where you can run the UV lamp for a couple of hours, perhaps with the chlorinator off of when the chlorinator is not running. That way the UV can work on breaking down bather waste. Then you can shut the UV off and put the system back into normal run mode so that the chlorinator can make chlorine. This would be especially useful for those times when you are using your attached spa. Hot tubs and spa are great at making people sweat and adding lots of bather waste to the water. If you can run the UV oxidizer while people are in the tub, then the UV can breakdown a lot of the gunk people emit making it easier to re-establish a chlorine residual when everybody gets out without creating a lot of CC's in the process.

Paramount also sells a UV system -

Ultra UV2 sanitizer inactivates 99.9% of micro-organisms chlorine can't.

Eco-friendly, Ultra UV2 - Ultraviolet pool system immediately inactivates 99.9% of micro-organisms such as crypto and giardia that chlorine can't.

www.1paramount.com

Don't fall for all the marketing B/S about using less chlorine, blah, blah, blah. You primary goal in using UV is to breakdown bather waste BEFORE chlorine has to deal with it.

 

[Dirk]

The IpH's venting "system" is a 1/4" tube that runs from the acid reservoir tank to "someplace else." There is a large o-ring that seals the lid to the tank. So theoretically acid fumes should only escape from the vent tube. In practice? I couldn't say. Mine is outside, but very near my other equipment. I was concerned about that, and even took a few pics so that I could compare, year to year, if any amount of corrosion was happening, and how much. But I haven't really followed up on that. (Best laid plans...). I do see some tarnished stainless steel here and there, but I can't say definitively that that's being caused by acid fumes. In any case, it's not bad, at all, whatever is causing it. All I know is that Pentair did take reasonable steps to minimize this issue.

FYI: in case you didn't know... Your IC40 SWG produces chlorine in a binary fashion. 100% on, or 0%. Say you dial it to 5%. It's not making 5% strength chlorine, or anything like that. It's making 100% strength chlorine 5% of the time. The SWG cycles on and off to achieve the 5% output. I can't remember what the interval is, but at its 5% setting the SWG will be on for 3 minutes total every hour. At 50%, it'll be on for 30 minutes out of every hour. Etc. Your SWG has a life span (I think it's 10,000 hours) and then it's done. But that's 10,000 hours of chlorine-producing-time, not necessarily on-time. It doesn't matter if you run it at 3%, or 100%, you're going to get the same total lifetime amount of chlorine out of it either way. So adjust runtime and % settings in any way that best works for your pool, you won't save or spend any of the total chlorine output better or worse one way or another.

That said, there is one other consideration. If you set your SWG at 100%, with as low a runtime as possible, it'll dump as much chlorine into your pool as it can, non-stop, for X amount of time, once a day. Conversely, if the runtime is 24 hours a day, with a much lower % setting, then it will dispense X amount of chlorine at very regular intervals, all throughout the day. I prefer the latter, because the FC level stays consistent all day long, instead of high at one point during the day, and then tapering off to low just before the next run. With an IpH in tow, the same goes for acid dispensing. I don't run 24 hrs/day. I go about 12 (pretty much daylight hours). So during the day, my FC and pH are pretty much dead on, all day long. At night, the pH probably moves a little, but the FC not much, because there is no sunlight burning it off.

As Marty mentioned, it'll be your heating requirements that will likely determine your runtime. Or at least your minimum runtime. Same for me (though my heat is from solar). Everything else is adjusted to occur during my "heat run" of 12 hours (SWG setting, IpH setting, RPM settings, etc). My controller ramps up the pump RPMs for solar heat (about 2200 RPM), and then ratchets down when my heat setting is reached. For me that's 1500 RPM. For whatever reason, that's the minimum at which my SWG will run reliably. As long as it's not indicating "Low Flow," the output of the IC (and IpH) is unaffected by flow rate (RPM).

Just some things to consider as you experiment with your various settings and runtimes.

 

[crustacean]

@ajw22 @mknauss @JoyfulNoise Thank you for the feedback and clearing up my misconceptions. We had a pool as a kid and I've always wanted one since but it's been an adventure bringing it up! I haven't described the HVAC at all but my dream is that once I get everything sorted just right it'll truly be a pleasure keeping things just right.

I am going to get CYA into the pool ASAP. The explanation about the UV makes a lot of sense, particularly in spa mode after we've added the CYA.

Per request here's my double-valve automation scheme as currently plumbed. Curious if it's worth changing to some other configuration or just accept it works and doesn't leak. I feel like keeping the spa in this minimum spillover mode is good just to make sure I really mix my pool and spa water after we use the spa. I feel better trusting 10,000 gallons to sanitize than just the 500 but maybe I have the wrong idea on this. I admit I haven't looked hard at how people automate their pool/spa combinations.


I don't have a great picture of the entire "pad" but here's this one (before drain valve became automated):


I currently have a heat exchanger plumbed into a poolpak that really needs to be re-routed to just the pool. Those manual balancing valves don't seem easy to get the flows right, and I can't understand how they'd ever work when I'm varying the speed constantly. Plus it can't dump heat into a 100F spa which is really when the dehumidifier is working hard. My plan was to instead have a small circulation pump (~5GPM) that always runs the exchanger from the pool drain to the pool returns and bypasses the main pump/filter/heater/swg loop entirely. It won't be filtered (beyond whatever screen is in the pump) but I'm hoping that is OK!

 

[crustacean]

The IpH's venting "system" is a 1/4" tube that runs from the acid reservoir tank to "someplace else." There is a large o-ring that seals the lid to the tank. So theoretically acid fumes should only escape from the vent tube. In practice? I couldn't say. Mine is outside, but very near my other equipment. I was concerned about that, and even took a few pics so that I could compare, year to year, if any amount of corrosion was happening, and how much. But I haven't really followed up on that. (Best laid plans...). I do see some tarnished stainless steel here and there, but I can't say definitively that that's being caused by acid fumes. In any case, it's not bad, at all, whatever is causing it. All I know is that Pentair did take reasonable steps to minimize this issue.

OK. I do have a small extraction fan running 24/7 providing negative pressure between poolroom and house so I could probably tie this hose in and apply negative pressure on the tank, too. In worst case I was planning on doing that to some chemical enclosure but the ipH is cheaper than a lot of real hazmat cabinets!

FYI: in case you didn't know... Your IC40 SWG produces chlorine in a binary fashion. 100% on, or 0%. Say you dial it to 5%. It's not making 5% strength chlorine, or anything like that. It's making 100% strength chlorine 5% of the time. The SWG cycles on and off to achieve the 5% output. I can't remember what the interval is, but at its 5% setting the SWG will be on for 3 minutes total every hour. At 50%, it'll be on for 30 minutes out of every hour. Etc. Your SWG has a life span (I think it's 10,000 hours) and then it's done. But that's 10,000 hours of chlorine-producing-time, not necessarily on-time. It doesn't matter if you run it at 3%, or 100%, you're going to get the same total lifetime amount of chlorine out of it either way. So adjust runtime and % settings in any way that best works for your pool, you won't save or spend any of the total chlorine output better or worse one way or another.

That said, there is one other consideration. If you set your SWG at 100%, with as low a runtime as possible, it'll dump as much chlorine into your pool as it can, non-stop, for X amount of time, once a day. Conversely, if the runtime is 24 hours a day, with a much lower % setting, then it will dispense X amount of chlorine at very regular intervals, all throughout the day. I prefer the latter, because the FC level stays consistent all day long, instead of high at one point during the day, and then tapering off to low just before the next run. With an IpH in tow, the same goes for acid dispensing. I don't run 24 hrs/day. I go about 12 (pretty much daylight hours). So during the day, my FC and pH are pretty much dead on, all day long. At night, the pH probably moves a little, but the FC not much, because there is no sunlight burning it off.

I figured it was using PWM and am glad it can handle such low values as I don't need much. It does seem gentler to do it gradually, especially when I have it covered most of the time.

As Marty mentioned, it'll be your heating requirements that will likely determine your runtime. Or at least your minimum runtime. Same for me (though my heat is from solar). Everything else is adjusted to occur during my "heat run" of 12 hours (SWG setting, IpH setting, RPM settings, etc). My controller ramps up the pump RPMs for solar heat (about 2200 RPM), and then ratchets down when my heat setting is reached. For me that's 1500 RPM. For whatever reason, that's the minimum at which my SWG will run reliably. As long as it's not indicating "Low Flow," the output of the IC (and IpH) is unaffected by flow rate (RPM).

With the room air temp 2 degrees above the water temperature, most of my losses are from the ground and piping to the equipment room. I keep trying to stare at the intellicenter graphs but they really don't zoom well on a mobile device. I suppose I could let the temperature drift more when we won't be using it but with the room HVAC it's probably simpler to keep things as constant as possible.

 

[ajw22]

When you are using your spa does the water spillover into the pool?

You are missing an actuator on the diverter into the pump suction that would automatically switch the pump between your pool skimmer and the spa drain. You can’t use the normal SPA or SPILLOVER functions of the IntelliCenter without this suction actuator. Or is that an old picture?

 

[Dirk]

OK. I do have a small extraction fan running 24/7 providing negative pressure between poolroom and house so I could probably tie this hose in and apply negative pressure on the tank, too.

If the equipment is in its own negative-pressure room, venting to the outside, that sounds fine for the IpH. The fan should take care of any errant fumes that might sneak out of the tank. But I wouldn't run the IpH vent tube into the fan, or the air stream it makes, if that's what you meant, for a couple reasons. The acid fumes from the tube will make quick work of anything metal in the stream, including the fan blades. And negative pressure in the tank is probably not great either. That vent tube allows air in as much as fumes out. As the pump moves acid from the tank to the pool, the tank needs air to displace the acid. Now your fan is not going to inhibit that very much, of course, but you get the idea. The IpH is designed to be sealed tight, so it needs that vent tube to work properly.

I would just run the tube through the exterior wall and let it vent outside. You'd want the end of the tube located as far from anything metal as possible (window frames, downspouts, hose bibbs, door hinges, fence nails, etc). I have mine pointing down slightly, so that rain can't enter the tube, which could inhibit the air flow somewhat.

Like the way I already spent your money on the IpH and have it all installed for you already? Yah, that's how we do!

 

[crustacean]

When you are using your spa does the water spillover into the pool?

You are missing an actuator on the diverter into the pump suction that would automatically switch the pump between your pool skimmer and the spa drain. You can’t use the normal SPA or SPILLOVER functions of the IntelliCenter without this suction actuator. Or is that an old picture?

Yes that is an old picture there is an actuator now. Here is a better picture:

 

[crustacean]

Like the way I already spent your money on the IpH and have it all installed for you already? Yah, that's how we do!

Yeah I knew there would be a few things I wanted to iron out before calling the installation completely finished. UV, chemical doser, mini circulator for my poolpak...once I stop adding things for a while I'll think about doing it!

 

[wireform]

Yes that is an old picture there is an actuator now. Here is a better picture: View attachment 394111

As per the installation manual (page 22) the cell is supposed to be mounted vertically meaning the display facing up, you have it sideways.