quantumchromodynamics
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Posts posted by quantumchromodynamics
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Aerate until your pH gets to 7.9 and then add enough 31.45 % muriatic (hydrochloric) acid to lower it to 7.1. Continue to do this until your TA gets to about 100 ppm. Then allow the pH to settle at a level to see if you need to lower the TA any more, or leave it at 100 ppm.
A calcium of 100 ppm is fine, I would leave it there.
You can get muriatic acid from any hardware store
You can use the the pool calculator to calculate your CSI and to determine dosages of chemicals to add.
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I really don't see the need for the patent, or the additional ingredients. It seems to me that they are going out of their way to make it seem like they have created something new and different. At best, they have figured out that MPS can convert some chloride to chlorine in a high salt environment.
They refer to it as an "invention". I don't see how they have invented anything. All they're doing is mixing different spa chemicals into one product. That's not an invention. I think that the added ingredients are mostly counterproductive. They can be added separately if necessary. They are more likely to mess up the chemistry than help.
The MPS is the only thing that is doing anything, and even that is not necessary. Their primary claim is the creation of chlorine on demand, which can be achieved with sodium hypochlorite.
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I recommend that you get the Taylor K-2006 test kit (FAS-DPD). This will allow you to test FC (Free Chlorine) and CC (Combined Chlorine) to a precision of 0.2 ppm or 0.5 ppm.
You should maintain about a -0.3 CSI (Calcite Saturation Index) to prevent scaling in the salt cell. You can calculate your CSI by using the the pool calculator
As long as your chlorine demand is not excessive, and you don't have any CCs, then you don't need to shock. I recommend that you use your salt system to provide the baseline chlorine demand and that you use chem geek's rule of thumb for additional oxidizer based on usage.
Chem geek's rule of thumb regarding the addition of oxidizer is for every person-hour of soak time you need to add 3.5 teaspoons of dichlor or 5 fluid ounces of 6% unscented bleach or 7 teaspoons of 43% MPS. This can be helpful in determining the correct amount of oxidizer to add. This is just a starting point. You will need to adjust the amounts based on your test results. With the salt system, you should need somewhat less than the aforementioned amounts. The key is to maintain about 2 to 4 ppm FC and less than 0.5 ppm CC (Ideally, CC should be kept at zero).
You should test before you soak and the level should be about 2.0 ppm FC with no CC.
I recommend that you use dichlor until your Cyanuric acid level reaches 20 to 30 ppm and then switch to liquid chlorine or MPS. For liquid chlorine, you can use regular, unscented 6.0 % bleach (sodium hypochlorite). Once you get cyanuric acid in your water, you should maintain a FC of about 7.5 % of your Cyanuric acid.
MPS will probably increase your chlorine levels if you use it, so you should be careful not to add too much. It can also register on the CC test. There is a special reagent that you can get to remove the MPS CC interference.
I recommend that you read the following:
Nitro's approach to Water Maintenance
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There are some references that indicated that MPS can oxidize chloride to chlorine. I don't think that this happens very much in most pools or hot tubs. However, in this case, where the water is hot and the salt level is at 3,000 ppm, it probably creates some chlorine.
This patent indicates that MPS can oxidize chloride to chlorine at a measurable rate when the salt level is elevated, such as in a salt system.
The second order polynomial equation derived from the above data in Table 1 at 29° C. is:Free chlorine concentration (mg/kg) = (0.040t−0.0024t 2 )×C 0
where C 0 =initial OXONE concentration in mg/kg (for C 0 =6 to 96 mg/kg) and t is time (h).
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The solubilities of DCDMH, DBDMH and BCDMH are about 500 ppm to 2,000 ppm (depending on data source). The bromine and chlorine hydrolyze in water and the DMH is left. DMH is more soluble in water than BCDMH (one reference shows 4,516 mg/l).
http://en.wikipedia.org/wiki/BCDMH
Silver is not compatible with bromine. Due to the low solubility of silver bromide, it is not possible to maintain sufficient silver levels to be effective. Silver levels will typically be in the ppt (parts per trillion) range. 1 ppt = 1 millionth of a ppm.
For example, silver bromide will be at saturation when the bromide level is 10 ppm and the silver level is only 0.000465 ppm = 465 ppt (parts per trillion).
Studies indicate that silver should be in the 20 to 40 ppb (parts per billion) range to be effective.
silver concentrations of 0.02 to 0.04 mg/liter are recommended for sufficient disinfection levels according to in vitro and field studies.http://www.intec-america.com/resources/Coliform_Bacteria.asp
Note: Silver in drinking water is limited to 100 ppb. There are no studies that indicate that less than ppb levels of silver have any antimicrobial effect.
Maintaining 1 to 2 ppm of bromine is generally safe as long as the level is kept consistent and the level of dimethylhydantoin is limited.
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Thanks Hillbilly Hot Tub and Chem Geek. I have heard that after adding MPS it is okay to enter the tub after waiting 15 - 30 minutes. So after 30 minutes would one expect that there would be no "active" MPS in the tub or any negative aspects?
The rate of dissipation of the MPS will depend on the oxidizer demand. If there are a lot of organics to oxidize, then the MPS will be consumed fairly quickly at hot tub temperatures. If there are not a lot of organics to oxidize, then the MPS should last longer (perhaps 24 hours).
I think that you would be OK as long as you limited the amount of MPS to 1 ounce weight per 500 gallons of water and waited 1 hour before going in. I think it is better to add the MPS after soaking and based on chem geek's rule of 7 teaspoons per person hour.
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Ok, so the CX means that the motor is a PSC (Permanent Split Capacitor) switchless design. Your capacitor is a "Run" capacitor. There is no "Start" capacitor. Since there is no start capacitor, the motor will have significantly less starting torque than a capacitor-start motor.
Any excessive resistance could keep the motor from starting. You can check the impeller for debris by removing the pump basket and sticking your finger into the hole going to the impeller. The impeller should be clear of debris and easy to turn. Make sure that the pump can't turn on while you are reaching in by turning off the power at the circuit breaker.
Even though the motor is called "switchless", I still think that there might be a switch under the end cap that might need to be cleaned. That would be the next step if nothing else works.
FAILURE TO START(MOTOR HUMS OR ATTEMPTS TO START)
■ Check voltage at motor line terminals. If voltage is inadequate to start motor, check for loose connections, undersized wiring, overloaded circuit or other causes of voltage drop.
■ Start switch contacts not closed when motor is not operating. Switch may require adjustment. Switch contacts dirty or pitted.
■ Capacitor (where used) is “shorted” or “open”.
■ Check motor windings for “open” or “short”.
■ Check for continuity through protector.
■ Turn the motor shaft by hand to get the “feel” of the motor. If the shaft feels tight or doesn’t turn smoothly:
• Check the bearings for smooth operation. • See if there is evidence of the rotor striking the stator.
• Check for internal corrosion, cracked end frames, clogged fan or other obstruction within the motor.
• Check pump for obstructions, binding impeller, or bent shaft.
I'm not sure that there is a switch. The motor is called "switchless", so perhaps it doesn't have one. The capacitor is involved in starting, so that is the best place to start. The above reference gives other things to check. The reference shows how to check the capacitor, windings and the protector (Thermal Overload).
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Those chemicals soften the water by forming insoluble calcium compounds. The calcium precipitates out as a granular powder, and as scale. I recommend against trying to remove calcium this way as it makes a mess and could scale the tub and equipment. You can manage the CSI by keeping a lower carbonate alkalinity and/or a lower pH. Adding a metal sequestrant could also help.
If you want to reduce the calcium level of your fill water, then you should use a water softener.
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10 ppm should be fine for a shock. Keep the cover open to allow any gases to get out. Silver is not compatible with bromine due to the low solubility of silver bromide.
Chem geek's rule of thumb regarding the addition of oxidizer is for every person-hour of soak time you need to add 3.5 teaspoons of dichlor or 5 fluid ounces of 6% unscented bleach or 7 teaspoons of 43% MPS. This can be helpful in determining the correct amount of oxidizer to add. If you have an ozonator, the amounts will generally be less.
The key thing is to maintain a consistent bromine level and to never allow the level to drop below 1.0 ppm. Test frequently and maintain a consistent 2 to 5 ppm.
Read waterbear's post on how to do bromine properly. Waterbear's post
I think that there should be a correction factor for the level of bromine and for the shock level for bromine due to the dimethylhydantoin concentration. DMH (Dimethylhydantoin) is the carrier chemical in bromine tabs similar to how cyanuric acid is the carrier in dichlor or trichlor. DMH builds up over time and reduces the reaction rate of bromine in a similar way to how cyanuric acid reduces the reaction rate of chlorine.
The problem is that we do not know the equilibrium constants to determine the correct ratios. I recommend that DMH be kept to less than 100 ppm (Others show 200 ppm). I recommend that the use of tabs be minimized and that the water be changed at least every 3 months. As the level of DMH increases, I recommend a slightly higher level of bromine and more frequent shocking.
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Note: Monobromamine is nearly as active as free bromine due to the presence of the monobromammonium ion.
NH2Br + H+ < > NH3Br+
The equilibrium constant is 3.2 x 10-7 at 25o C. pK = 6.49.
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The "U" is actually the Greek letter Mu ("µ"), which means micro, which means one millionth. You have a 30 microfarad capacitor (30 µF) = (30 MFD). Make sure that the size dimensions match up.
I think that there is a switch in the back under the end cap. You have to remove the 4 long through-bolts and pull back the end cap to get at the switch. If the pump is old, the through-bolts can break due to corrosion and the torque from the bolts being so long, and you might not be able to reassemble the motor. Make a mark on the end cap and motor to make sure you can realign the end cap so that the through-bolts line back up with the holes.
Before removing the end cap, replace the capacitor, and check the impeller for debris to see if that will work. Sometimes the impeller will get clogged and that can create enough resistance to prevent the motor from starting since it has less starting torque than normal.
Type: This is a code for the electrical design of the motor. For example, A. O. Smith uses “CX” to identify its PSC (Permanent Split Capacitor) switchless design. Other codes are “CS” for capacitor start; “SP” for split phase and “UAK” for capacitor start/capacitor run.What does your motor label say for "type"?
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You can get capacitors at any motor shop. Look under electrical motors online or in the yellow pages..
That type of motor uses a centrifugal switch for starting. On startup, the switch is closed, and as the motor reaches speed, the switch opens. Over time, the switch contacts get oxidized and don't make good contact. Clean the contacts of the switch.
Capacitor Check (Start or Run)• Set ohmmeter at Rx 1K.
• Slip a heavy piece of paper between points on the switch.
• Discharge capacitor by touching the two terminals simultaneously with the blade of an insulated handle crewdriver
• Attach one probe to each terminal. Ohmmeter needle should move rapidly to right then slowly drift to the left. (Low ohm reading to high ohm reading.)
• If digital meter is used, readings should start low and rapidly increase to maximum value.
• Replace capacitor if bad.
TIP: The replacement capacitor must be the same MFD as the original. However, if the same voltage rating is not available it is acceptable to use the next higher voltage. Example; if a 370 volt unit is not available, use the next rating, 440 volt.
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One of the difficulties is that when bromine is used in conjunction with a metal ion the metal ion and the bromine interact to reduce the effectiveness of the metal ion in killing microorganisms, oftentimes to a level that renders the metal ion concentration ineffective to kill microorganisms, thus negating the reason for using the two biocides.
However, when two or more biocides or disinfectants such as a metal ion disinfectant is used in conjunction with bromine the level of metal ions in the water can be adversely affected so that the level of metal ions becomes insufficient to provide for effective control of microorganisms in the body of water thus rendering the combination impractical.
Thus, the advantage of having metal ions in combination with bromine for use in treating a body is water is lost since the bromine can reduce the metal ion concentration in the water to levels that are ineffective to rid the body of water of microorganisms that normally would be killed by the presence of the metal ions.
Calculations reveal that when metal ions and bromine are combined the bromine limits the available metal ions in the body of water to levels that are ineffective to control the microorganisms in the body of water.
The level of silver ions in the spa was measured weekly. It was found that the level of silver ions in the spa ranged from about 1-3 ppb during the test. The pH was maintained in the range of 7.24 to 7.99 during the test.
The above reference patent specifies that a chelating agent is needed for the silver to be effective.
a chelating agent selected from the group consisting of 1-bromo-3-chloro-5,5 dimethylhydantion, 1,3 dichloro-5,5 dimethylhydantion, 1,3 dibromo-55 dimethylhydantion, anthranilate, saccharinate and sulfadiazine into the body of water to maintain the effectiveness of the silver ions in killing microorganisms.However, if the silver is chelated, then I don't think that it will be active.
You could probably get EPA approval for a sand and bromine system because the bromine is doing all of the work.
It is also important to note that the highest possible concentration of silver is limited by the bromide ion concentration. For example, if the bromide ion concentration were only 1 ppm, then the silver ion concentration could be maintained at about 4.65 ppb (parts per billion). However, if one were to add sodium bromide initially, then the bromide ion concentration would be much higher and would significantly limit the silver concentration.
In their patent, they do not initially add sodium bromide to the water. That would allow them to maintain the 1 to 3 ppb levels that they claim. However, once the bromide levels increased, the silver ion concentration would drop significantly.
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One of the problems associated with the use of silver for killing microorganisms is that silver has a tendency to complex with other compounds and become increasingly insoluble thereby reducing the effective microorganisms killing ability of the silver.
For example, it would not be anticipated that silver chloride when used in combination with sodium bromide would be an effective prolong disinfectant system because of the combination's tendency to form insoluble silver bromide crystals, which are not believed to be biologically active in aqueous environments.
However, it has been discovered that if silver forms a complex with hydantoins, the silver will remain soluble to a higher degree thereby retaining the silver's antimicrobial activity. - Joseph A King, King Technology.
Silver-based cartridges are not compatible with bromine sanitizers because of the insolubility of silver bromide.Also note that all of the other silver based systems, such as Nature2, specify that their system is not compatible with bromine.
Nature2 Spa CompatibilityAttention: Not to be used with product containing bromine, sodium bromide, or biguanides. If these products are being used, be sure to drain and refill the spa with fresh water..
http://www.nature2.com/files/TL2700_Nature2_Spa_Owners_Manual.pdf
Mineral/Vision NOT compatible with Bromine. Results in Silver Bromide forming in your tub.Thermo Spas developed Thermo Clear; a two-step, mineral-based system that is extremely easy to use and is compatible with all hot tub brands.Disadvantages: Not compatible with bromine
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I would avoid silver in a bromine tub due to the low solubility of silver bromide, which is only 140 ppb (parts per billion). Solubility product, Ksp 5.4 × 10-13. For example, if the bromide concentration were 79.9 ppm (0.001 M), then the water would be saturated with silver bromide when the silver concentration reached 5.8 x 10-5 ppm (58 parts per trillion). I would think that the silver would never reach a concentration sufficient to do any good.
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For anyone interested in learning more about chemistry, you might want to check out Khan Academy, where they have videos on various subjects, such as this video about chemical reactions in equilibrium.
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It's just a typical salt system. They are just trying to be clever by calling the cell a "hydroxinator" because it creates hydroxide just like every other salt cell. They are trying to convince people that the hydroxide is the key benefit.
Their claim of creating "magnesium hydroxide" is nonsense. The concentration of hydroxide in the general water is determined by the pH. Their claim of creating some sort of special chlorine is also nonsense. Chlorine is constantly changing from hypochlorous acid to hypochlorite to chlorinated cyanurates. The amount of time chlorine spends as each type depends on the pH and the cyanuric acid concentration.
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Replace the housing gasket, diffuser gasket and the seal assembly. Check the seal plate, impeller, diffuser and impeller ring and replace any that are bad. Check the impeller threads to make sure that they are not stripped.
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It's sodium bisulfate! <----- where do you find this just wondering, found everything else but this
Sodium bisulfate can be found in any pool/spa store. It is sold as dry acid. It is a granular form of pH down. I prefer muriatic acid instead of sodium bisulfate.
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A pressure washer should not be used. The pressure is too high and could damage the fabric. You should clean your filters according to the instructions here. Most TSP that you will find locally is not real TSP, and does not work as well as real TSP. You can get real TSP here. You should get a second set of filters so that you can allow one to soak while using the other set.
What is the procedure to clean my filter cartridge?1) Remove the cartridge from the filter housing following the manufacturer’s instructions
2) Use a garden hose with a straight flow nozzle to wash down the filter element. Work from the top down, holding the nozzle at a 45 degree angle, and wash all the pleats with emphasis between the pleats.
3) Rinse until all dirt and debris is gone
4) For all spa cartridges and elements used in swimming pools where perspiration, suntan lotions, and other oils are present, soak the element for at least one hour (overnight is most effective) in:
A) a commercial filter cleaner, or,
B. one cup tri sodium phosphate (TSP) to five gallons of water
C) one cup dishwasher detergent to five gallons of water.
5) Rinse the cartridge again to remove oils and cleaning solution.
6) If the filter has a coating of algae, calcium carbonate (residue from calcium hypo chlorite), iron, or other minerals, soak the cartridge in a solution of one part muriatic acid to twenty parts water until all bubbling stops.
7) Rinse the filter cartridge clean and reassemble housing.
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the clarity is much greater without the "chlorine tint" and many more benefits.
The clarity of a salt pool and a non-salt pool should be equal. There is no such thing as a "chlorine tint".
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One of the issues with using salt in a plaster pool is that plaster needs a neutral to slightly positive CSI to get maximum longevity out of the plaster, while the salt cell needs a slightly negative CSI to get optimum results.
My opinion is that if you use a salt system on a plaster pool, then you will have to compromise on one or both of these things.
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You repeat almost verbatim chemistry that others have posted time and again
Here is my most recent post with chemistry information. Post a link to anyone who has said the same or similar thing.
Dimethylhydantoin has a pKa of 9.19. Here are the correction factors for DMH:pH........% DMH
7.0..........0.251
7.1..........0.315
7.2..........0.396
7.3..........0.497
7.4..........0.623
7.5..........0.78
7.6..........0.98
7.7..........1.22
7.8..........1.53
7.9..........1.91
8.0..........2.37
For example, at a pH of 7.9 and a DMH level of 200 ppm, the DMH will contribute 3.82 ppm to the TA.
How much of the chemistry information that you post is a result of your original research? What chemistry information have you posted that has not been posted by others?
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High concentrations of dimethyl hydantoin (the DMH in BCDMH) are known to build up in pools treated with bromo-chloro-dimethylhydantoin, tying up bromine and reducing effectiveness. Problems similar to those that occur in chlorinated pools overstabilized with cyanuric acid result. Oxidation reduction potential (ORP) levels plummet as the brominated pool water ages. The minimum 750 mV ORP levels often become difficult to reach.
In a study conducted by Olin Chemical of commercial pools using BCDMH (Technical Bulletin "Bromine Use in Swimming Pools: Exploding the Myths"), results showed that the concentration of organics was three times higher than that typically found in chlorinated pools, DMH levels were elevated, more than half the bromine measured by DPD total bromine test kits was bromamine rather than free bromine, and the pools reported continuing problems with cloudiness and bather skin irritation.
The dimethylhydantoin in the tablets seems to have a similar (but not identical) function in a bromine system as CYA does in a chlorine system. It tends to stabilize it but, like CYA, too much is not good.Like chlorine, unstabilized bromine is 90% decomposed by sunlight in 3 h. Polarographic studies show that cyanuric acid (CA) reacts with free bromine (ie, HOBr and BrO) forming bromoisocyanurates, which improves stability at sufficiently high CA concentrations, but not as effectively as stabilization of chlorine (9). Dimethylhydantoin, the parent compound of BCDMH, provides better stability, but still not equivalent to stabilization of chlorine by CA (9).9. J. A. Wojtowicz,J. Sw. Pool and Spa Ind.4(1), 9 (2001);5(1), 19 (2004); B. B. San- del, Olin Corp., unpublished Data on Testing of Copper-Silver Cartridge, 1992.
Kirk-Othmer Encyclopedia of Chemical Technology
As the chlorine and bromine in BCDMH are used up the amount of the DMH part of the chemical in the pool increases. Excessive DMH affects the disinfection efficiency so the level must not be allowed to get too high. The concentration should not exceed 200 ppm.http://www.swimming-pool-chemicals.co.uk/sp-water-chemicals.html
Facilities using bromine as a sanitiser shall keep the DMH levels no greater than 200 milligrams per litre.http://cat1.poolsafety.com.au/uploaddocs/Code_of_Practice_Aquatic_Facilities%20May%202010.pdf
Dimethylhydantoin (DMH) is a disinfection by-product of BCDMH, which has been associated with skin irritation (bromine itch) when the DMH concentration in pool water becomes too high. Pool operators need to maintain DMH below 200 mg/L. This is achieved by frequent backwashing and dilution with fresh water.Heavily used spa pools within high-risk premises (such as nursing homes) should be emptied and cleaned weekly. Spa pools which are infrequently used and well maintained are likely to maintain good water quality and therefore could be emptied less frequently (maximum three months).
Bromine, like chlorine, may be degraded by sunlight. The carrier compound of BCDMH and DBDMH, the dimethylhydantoin (DMH), has been found to protect the bromine residual from sunlight. However, that protection is much less than the protection cyanuric acid gives to chlorine. -
I would be more interested in the research that formed the opinion that 200 ppm is the upper limit for DMH rather than a brief sentence that it should be limited to 200 ppm.
Hmmm...interesting. Here is someone giving an easy answer, and you're like "Hey, wait a minute. That's not good enough. That's not acceptable. I want to see the research that backs up their opinion about the 200 mg/l limit."
Notice that you refer to it as their "opinion", not as a fact. You are not willing to accept it until you see the chemistry for yourself. You find it deeply unsatisfying that someone just gives an answer without providing any explanation or science. This proves my point.
Is Spa Frog Safe At 1-2 Ppm Bromine
in Hot Tub Water Chemistry
Posted
The solubility of silver is dependent on the level of bromide, not bromine.
If you add 0.5 ounces of sodium bromide per 100 gallons on fill up, that starts you out with 16 ppm bromide. That means that a silver level of 291 ppt (parts per trillion) will saturate the water with silver bromide. For every 10 ppm of bromine that you add from bromine tabs, your bromide level will increase by 5 ppm.
The solubility product (Ksp) of silver bromide is 5.4 × 10^-13, which is very low. The solubility product is the product of the molar concentration of silver x the molar concentration of bromide.
107,868 ppm of silver = 1 mole per liter of silver (1M)
79,904 ppm of bromide = 1 mole per liter of bromide (1M).
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Example
10 ppm of bromide = 1.2515 x 10-4 moles per liter
5.4 x 10-13 = (1.2515 x 10-4M)(molar concentration of silver)
The molar concentration of silver is 4.3148 x 10-9M
The concentration of silver in ppm is 4.65 x 10-4 ppm, which equals 465 ppt.
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On startup, your level of bromide will be 16 ppm, which will limit the silver concentration to 291 ppt.
The concentration of silver is too low to do any good. All other silver ion products specifically say that their silver ion product is not compatible with bromine/bromide.
I recommend a minimum level of bromine of 1.0 ppm at all times. Note: This is not a target level, it's just a minimum.
I recommend that you maintain about 2.0 ppm to 3.0 ppm on startup, about 2.5 ppm to 3.5 ppm after 30 days of using tabs, about 3.5 ppm to 4.5 ppm after 60 days of using tabs, and that you change the water at least by 90 days.
The progressively higher levels of Total Bromine are to help compensate for the increasing levels of dimethylhydantoin from the tabs. Periodic shocking with regular, unscented 6.0 % bleach or MPS can help eliminate any bromamines that might have accumulated. Since there is no readily available test for bromamines, you should carefully monitor your bromine demand and compensate accordingly.