Moblaine's pool

[chem geek]

The efficacy data says "The product must be used in conjunction with an EPA-registered source of chlorine (such as Chlorine Bac Pac)." They amended the registration for use in spas and bromine may be used in place of chlorine. They did their actual tests using the equivalent of what would occur from the use of bromine tabs (BCDMH) with their product with 1.3 ppm BCDMH with 2.6 ppb silver ions. The lab results supported use of the Spa Frog with bromine in the 0.9 to 2.25 ppm range. The EPA approved their label which has 0.5% silver chloride as the active ingredient to claim disinfection and the use of chlorine or bromine at 50% of the levels they would be used at by themselves. So instead of 1 ppm FC or 2 ppm bromine, it's 0.5 ppm FC or 1 ppm bromine. Note, however, that their claim that it reduces chlorine or bromine "use" by 50% is only true to the extent that ALL chlorine or bromine loss is from sources proportional to their level such as loss from sunlight or oxidation of fixed amounts of chemicals or surfaces. So IF one maintained a lower chlorine or bromine level in an outdoor residential pool, then one would use less chlorine or bromine. HOWEVER, silver ions (unlike copper ions) do not prevent algae growth so in practice one still needs to maintain a chlorine or bromine level sufficient to prevent such growth. For chlorine in an outdoor pool, this means an FC sufficient for the CYA level and that level will not be lowered at all by the presence of silver ions. The loss of chlorine or bromine from killing bacteria is too small to be measurable in test kits.

In a spa used every day or two, it is the bather load that determines the bulk of the chlorine or bromine usage, not the minimum level of chlorine or bromine that is to be maintained. So there will be no savings when using silver ion in a frequently used spa. In a spa used infrequently, once a week or less, then one can maintain a lower chlorine or bromine level so could get a modest amount of savings in usage.

So for an outdoor residential pool, there is no savings from using the Frog. If one wants to spend more to have "savings", then one can use an algicide. Copper ions would work to prevent algae, but can stain pool surfaces and turn blond hair greenish, but Polyquat 60 weekly would also work and let one have a lower FC target level relative to CYA and therefore save on chlorine. However, the cost of the Polyquat exceeds the savings in chlorine so this is not normally done. It only makes sense for those who want a lower active chlorine level in their pools and are willing to pay for that possibility.

By the way, silver ions can most certainly stain pool surfaces (mostly plaster) and they are very nasty black stains. This is why the silver ion level is kept so low and why pH also needs to be controlled so that it doesn't get too high.

I'm missing the point of the Pool Frog discussion in this thread. It doesn't provide any practical value so why is it being discussed? The only benefit of having the silver ions in the water is some level of "insurance" if the chlorine level gets to zero since uncontrolled bacterial growth will be somewhat inhibited. However, since it won't prevent algae growth it's really not that great insurance.

[BigDave]

Ah! so it's silver.

[PoolDoc]

I'm missing the point of the Pool Frog discussion in this thread. It doesn't provide any practical value so why is it being discussed? The only benefit of having the silver ions in the water is some level of "insurance" if the chlorine level gets to zero since uncontrolled bacterial growth will be somewhat inhibited. However, since it won't prevent algae growth it's really not that great insurance.

I believe Moblaine (the OP) has a Frog system, and was questioning some of our suggesting that he simply abandon it. As I understand it, he's cutting open the trichlor refills, so he can refill them manually himself, but is still buying and replacing the mineral component. I think he was uncomfortable with the suggesting that Pool Frog (or at least, the mineral component) "doesn't provide any practical value", and questioned our claims, based on the report from King that no copper was present.

[moblaine]

I don't know what that could be. As noted above, the "mineral pack" contains 99.5% of something "inert" but that doesn't mean it can't react with high chlorine. Can you take it out? It's not impossible that it's the source of your CCs. Are you pouring the chlorine in via the skimmer? If so, change to pouring directly into the pool, preferably in front of a return, so it will mix rapidly.

No, I'm pouring the liquid chlorine all around the pool each night, primarily in front of the return jets then I brush to move the water around. Yes, I can take the Mineral Reservoir out and see if things change but then I'm unable to use my tri-chlor tabs. Is this okay for a few days since in lieu of the tabs, I'd be super-chlorinating each evening? Or, am I asking for trouble that way?

[moblaine]

I did feel a bit like I was being attacked for using the Frog even though I've never had any problems. My pool person (a friend who installs and has one himself) set me up with it and it's worked great for 7 years. This year, my only problem was initially not getting any FC reading and now that I have my Taylor test kit, I'm seeing that my CC is higher than my FC and I attempting to correct that. Various people on this forum started talking about copper in my water but I have verified my copper test is showing no copper and we've NEVER had green hair. So, I did ask King Technology about the copper and they told me there was no copper but by using the mineral pack (which includes silver and limestone) I am able to operate at chlorine levels of 0.5 to 1 ppm but that if I removed the mineral reservoir then I need to do at least 3 ppm. So, I'd like to just resolve my 1.0 ppm CC problem and then worry about algaecide and copper and all that other stuff later. I thank you for all your research into that issue. I saw bucket test directions on this forum somewhere but cannot locate them now. Is there a link?

[PoolDoc]

You can run without the Frog, while you are adding the bleach.

I don't think the Frog is the problem, and it sounds like it may be a better than average trichlor feeder. You pay a premium for it, but if it doesn't bother you, it doesn't bother me.

It's unlikely that the Frog is actually helping you run lower chlorine levels. But, I looked at the patent, and I think it's not impossible -- but the mode of action is probably not what they say. However, my guess is the DE filter helps more.

But, I'm going to make a suggestion: instead of worrying about CC levels, concentrate on whether chlorine levels hold from 8PM to 8AM. If you lose more than 1 ppm of FC overnight., you probably STILL need to shock. If you do NOT, you can probably move on to just enjoying your pool

[moblaine]

Thanks Ben. That seems like a bit of good news. It's a little after 8 pm so I am going out right not to add 4 gallons of 12.5% liquid chlorine. When I get up in the morning, I will test but how will I know how much FC it held overnight?

[PoolDoc]

I'm posting too late (I assume).

But, you have to add, wait 1 hour, test, then test again in the AM. Try again tomorrow.

However, 4 gallons of 12% should raise your FC by 18 ppm. So, if your chlorine is below 10 ppm in the AM, you still have a problem. Unfortunately the problem could be stale bleach!

[moblaine]

I will try it tonight or tomorrow night. In earlier post you said "If you lose more than 1 ppm of FC overnight., you probably STILL need to shock. If you do NOT, you can probably move on to just enjoying your pool." whereas, in your most recent post, you mentioned the 12% raising FC by 18 ppm and whether chlorine is below 10 ppm in the morning. Am I to be concerned if I lose 1 ppm overnight or 8 ppm overnight? Can you clarify so I'm sure to understand?

If I add the 4 gallons of 12.% tonight, wait one hour and test and the FC is somewhere around 18 ppm, that means the liquid is still good and not stale? Then I test in the morning and if I'm below 10 ppm FC then I have a problem?

We are scheduled for some sunshine over the weekend and into next week after having quite a bit rain lately. Will sunshine possibly help me get rid of some of the chloramines?

[PoolDoc]

Am I to be concerned if I lose 1 ppm overnight or 8 ppm overnight? Can you clarify so I'm sure to understand?

1 ppm. It sounded like you did NOT have an 8PM test, with with to compare the 8AM test, but I was pretty sure if you added chlorine as you said, you would get at least 12 - 15 ppm in the pool . . . and if it dropped 2 - 5 by 8AM, you definitely had a problem.

If I add the 4 gallons of 12.% tonight, wait one hour and test and the FC is somewhere around 18 ppm, that means the liquid is still good and not stale?

Probably. If your pool gallon figure is correct (and mostly, they are not!).

Then I test in the morning and if I'm below 10 ppm FC then I have a problem?

Dose in the evening. Test 1 hour later. Retest in the AM. If the PM test is greater than the AM test by more than 2 ppm or more, you need to keep shocking at night. If the difference is 1 ppm or less, you can stop.

We are scheduled for some sunshine over the weekend and into next week after having quite a bit rain lately. Will sunshine possibly help me get rid of some of the chloramines?

Yes.