New pool owner, new test kit, 1st results...oh my!

[mknauss]

The SWG super chorlinates the water as it passes through the cell giving a more effective use of the chlorine.

Not true. The increase in FC per unit volume is miniscule within the cell.

 

[ajw22]

Not true. The increase in FC per unit volume is miniscule within the cell.

The pool water all passing through the cell ensures it is all evenly chlorinated and disinfected. You get a much more even distribution of your FC in the water. That all prevents algae from taking hold.

 

[JimMarshall]

The pool water all passing through the cell ensures it is all evenly chlorinated and disinfected. You get a much more even distribution of your FC in the water.

I’m sorry, but that sounds like a sales pamphlet. FC no more evenly distributed than with someone who uses LC and has good circulation.


The truth if the matter is, SWCG users can target lower chlorine levels because the generator is continuously adding chlorine to replenish that which was consumed by the sun and organics.

Take a SWG pool with a CYA of 70 and a cell set up to keep the chlorine at 5.... the chlorine is always 5. If over the course of an hour, the pool is consuming 0.2 FC, over that same hour the generator produces enough chlorine gas to add 0.2 FC to the pool.... so the level remains constant at 5, which you’ll see is the recommended minimum for a non swg pool with a CYA of 70. In this pool, you target a FC of say 8, and then you use 3? FC during the day before making your once daily chlorine addition. Since you’re onky adding chlorine once, you need to stay at higher levels to make sure you don’t go below minimum before you make your next addition.

If you were continually checking and redoing your pool by hand hourly all day every day, or continuously dosing with a very low volume stenner pump all day long , you’d safely be able to follow the lower SWCG levels with LC usage.

 

[ajw22]

I’m sorry, but that sounds like a sales pamphlet. FC no more evenly distributed than with someone who uses LC and has good circulation.


The truth if the matter is, SWCG users can target lower chlorine levels because the generator is continuously adding chlorine to replenish that which was consumed by the sun and organics.

Take a SWG pool with a CYA of 70 and a cell set up to keep the chlorine at 5.... the chlorine is always 5. If over the course of an hour, the pool is consuming 0.2 FC, over that same hour the generator produces enough chlorine gas to add 0.2 FC to the pool.... so the level remains constant at 5, which you’ll see is the recommended minimum for a non swg pool with a CYA of 70. In this pool, you target a FC of say 8, and then you use 3? FC during the day before making your once daily chlorine addition. Since you’re onky adding chlorine once, you need to stay at higher levels to make sure you don’t go below minimum before you make your next addition.

If you were continually checking and redoing your pool by hand hourly all day every day, or continuously dosing with a very low volume stenner pump all day long , you’d safely be able to follow the lower SWCG levels with LC usage.

He can buy my sales pamphlet or yours. Either way he gets a consistently chlorinated pool with no work.

I see nothing in the TFP CYA/FC chart that says he can target a lower FC target if a stenner pump is being used.

 

[Dirk]

He can buy my sales pamphlet or yours. Either way he gets a consistently chlorinated pool with no work.

That doesn't mean you get to explain what is happening incorrectly. An SWG doesn't function like an ozone system. It's not killing things as water passes through it. Chlorine works fast, but not that fast. That might not be exactly what you meant, but that's the way you made it sound. The SWG puts a very small amount of chlorine into your pool, via all its returns, over a long span of time. That, along with good circulation, means the FC level is maintained more evenly and consistently than just dumping in a gallon once a day at one end of your pool, so an SWG user doesn't need to ramp up FC level as much to cover the loss of FC that occurs when it is dosed only once a day like that. An SWG will do its thing even if pump runtime and circulation is such that not all the water in a pool passes through it each day (which isn't likely to occur anyway, no matter how much you run the pump). The magic occurs out in the pool, not inside the SWG.

I see nothing in the TFP CYA/FC chart that says he can target a lower FC target if a stenner pump is being used.

My interpretation: The CYA/FC chart is a general guide that works for most users, and how they generally dose their pools (with either liquid chlorine or SWG). It doesn't take into account every possible scenario, including stunner pumps. So, for example, if a diligent PO dosed his pool with LC every half hour, he could reduce his target FC from the chart's recommendation. Conversely, if a PO had oversized his SWG and set it to 100% for only an hour a day, then he should raise his target FC, because he'd be introducing chlorine more like a LC user, than a typical SWG user. Some common sense is to be used when chlorinating a pool differently from what the chart was designed to cover. Otherwise, that webpage would need to contain a hundred charts to cover all the possibilities and no one new to TFPC would be able to figure it out.

 

[ajw22]

And what PPM of FC do you think is in the small amount of water in the cell?

When small amount of FC meets small amount of water has an effect. I am not disagreeing with the positive impact of a constant FC level. That constant FC level starts with the water in the cell.

You are welcome to your opinions and interpretations. Please don’t tell me what i intended to say.

The OP can believe whatever opinion works for him.

 

[Dirk]

OK, ajw is right. Well, at least about the part where I should not have attempted to give him the benefit of the doubt about what he intended to say. My bad.

To the OP, this is a teaching site, not a place for squabbling between posters who may or may not know what they're talking about. So for my part in that, I apologize. When it doubt, you can safely ignore me and any other un-credentialled poster, and defer to the TFP experts, of which Marty (mknauss ) is one. You can tell us apart by the badges displayed to the left of each post. Marty was very helpful in mentoring me when I first stumbled on to this site, and bless his heart he continues to, despite my rantings! His advice and knowledge are beyond reproach.

To address your original question about it, and summarize the ensuing attempts to answer it: The disinfection and benefits provided by the chlorine generated by an SWG are not happening within the body of the SWG any measurable amount more than anywhere else in the pool or its plumbing. Is there more chlorine at one end of an active SWG, and the pipe following it, than elsewhere in pool? Surely (but barely). Does that little bit of extra chlorine goodness work any better, or faster inside the SWG than elsewhere? No, not after the pool water has reached its target FC level. All the water is doing the disinfecting. The water that enters an SWG is already disinfected! If anything is in the water that needs disinfecting, that disinfection occurs in the pool, in the skimmer pipe, in the filter, before and after the SWG, etc. The SWG's function is to keep all the water's FC level even and effective, throughout the pool, throughout the day, not blast the portion of it within the SWG. JimMarshall, in his post #23, answered your question correctly.

I think most here would agree, if you make the switch to a saltwater pool and an SWG, you'll be glad you did. And you won't have to reduce your CYA any further!

 

[Vtown]

I appreciate all of the input and can see a SWCG sometime in the future. I’m sure I’ll have a bunch of questions when it’s time to go that route.

Pool had use today and when I checked tonight, had dropped about 3.5 from what was added in LC last night. Dosed to take it back to 11.

Question - if I’m going to be away and don’t want to use anything that would add more CYA, is there any harm in bringing my FC up to 31 prior to departure? This way if it drifted down 3 or so a day, I’d still be ok and above the suggested minimum 7 days later?

 

[Dirk]

That would certainly be great if we could do that. The problem is, the more chlorine you add above the recommended CYA/FC ratio, the faster it'll burn off. So you can't count on that "3 or so a day" and just multiply the number of days away by the normal FC consumption number. Someone here has a chart that shows what's going on, but I'm not sure where it is.

This is a pretty common subject: how to get your pool to stay sanitized while away. There are similar conversations about how to maintain pH while away, too. This is where an SWG really shines. Your primary options: SWG, Stenner pump, friends/family dose pool every day or two, tabs, pool guy. Pool guys typically show up once a week. It's virtually impossible to keep a pool properly sanitized in mid summer by dosing only once a week. Sounds like you understand why tabs are problematic, though many here do use them while away, and then deal with the fallout of added CYA or CH.

SWG and Stenner-based dosing solutions are not bulletproof, but they are relatively reliable and while they don't circumvent the necessity to test your water regularly to confirm they are performing as needed, stretching your testing schedule out to a week or so while away can be an acceptable risk. Safer for your pool than just dumping in a bunch of chlorine all at once.

Do you have anyone that would be willing to drop by once a day while you're gone? If you're confident in your FC loss per day, you can then calculate using PoolMath how much chlorine to add each day. Prepare that amount of chlorine in a plastic bottle, one for each day away, and label the set of them MON, TUE, WED, etc. Show your pal how you want him to add the chlorine each day, and purchase the necessary inducing elixir for his services (many here use a hops-based chemical for such a purpose). In essence you create a temporary chlorine injection system!

There are systems that measure and dose your pool for you, for both chlorine and acid, but they have their own set of challenges (and are expensive).

 

[Vtown]

Thanks for the reply Dirk. I guess I’ll figure something out for gettting some chlorine added while we’re away.

 

[JimMarshall]

Prepare that amount of chlorine in a plastic bottle, one for each day away, and label the set of them MON, TUE, WED, etc. Show your pal how you want him to add the chlorine each day, and purchase the necessary inducing elixir for his services (many here use a hops-based chemical for such a purpose). In essence you create a temporary chlorine injection system!

Doesnt even have to be a daily occurrence. I’m on vacation at the beach right now, left last Saturday the 30th. Before we left I took my pool up to a few PPM over shock level (didn’t verify level but I targeted 22 FC with a CYA of 50). I dropped off a case of beer and 2 gallons of 12.5 at the neighbors house with instructions to pour one full jug Tuesday and one today, each jug gives me 9.5 FC and I “normally” lose ~3 ppm per day at non shock levels.

By my math and previous experience with FC loss at shock levels, and with the pool covered, I expect to come home tomorrow to about 15 -17 ppm FC.

 

[Dirk]

There you go. If you're like me, you don't like to impose. But if the roles were reversed, and I didn't have a pool, and someone handed me the keys to theirs, in the middle of summer, I'd be buying them the case of beer!!

 

[sarahp1957]

Boy, am I glad I'm following this thread. Unfortunately, I don't have all of my test results on hand [my pool is in my second home in the mountains and I am in my primary home until Monday]. But my CYA has been sky high since I opened the pool a few weeks ago. A suggestion was made here to drain the pool and I kind of parked that idea while messing with my test kit. Now it looks like that's what I have to do. Bearing in my mind that I have an inground, vinyl pool, I now see that "floating my pool" is a real danger. But I think I have to drain it because I can't seem to get the CYA lower.

The pool was "closed" by some spa guys who didn't really explain what they were adding to the water. They drained half the pool and added some chemical. They told me that when I opened it, I should pump out the deep end water while adding fresh water to the shallow end. This made no sense and on this site, experts agreed. But I guess whatever they added is screwing up my tests and has contributed to my high CYA.

I thought I had logged my test results in my Pool Math app...but they aren't there. So I can't leave all my results. I will do so on Monday when I'm at the pool. Until then, trying to understand if draining is what I should do? And, more importantly, we've been swimming in the pool all along with these CYA. We're not dead...but should I keep everyone out until I figure out the CYA?

 

[ajw22]

Boy, am I glad I'm following this thread. Unfortunately, I don't have all of my test results on hand [my pool is in my second home in the mountains and I am in my primary home until Monday]. But my CYA has been sky high since I opened the pool a few weeks ago. A suggestion was made here to drain the pool and I kind of parked that idea while messing with my test kit. Now it looks like that's what I have to do. Bearing in my mind that I have an inground, vinyl pool, I now see that "floating my pool" is a real danger. But I think I have to drain it because I can't seem to get the CYA lower.

The pool was "closed" by some spa guys who didn't really explain what they were adding to the water. They drained half the pool and added some chemical. They told me that when I opened it, I should pump out the deep end water while adding fresh water to the shallow end. This made no sense and on this site, experts agreed. But I guess whatever they added is screwing up my tests and has contributed to my high CYA.

I thought I had logged my test results in my Pool Math app...but they aren't there. So I can't leave all my results. I will do so on Monday when I'm at the pool. Until then, trying to understand if draining is what I should do? And, more importantly, we've been swimming in the pool all along with these CYA. We're not dead...but should I keep everyone out until I figure out the CYA?

It is better if you start your own thread. Otherwise it gets confusing whose pool advice is intended for.

High CYA does not prevent you ftrom using your pool. What does the pool look like and what is the FC and PH level?

Post your test results on a new thread and folks will pitch in to help.