Kem Tek 338 vs Jack's Magic Purple Stuff in salt pool?

I've been using Jack's Magic Purple Stuff successfully for several years to prevent metal staining in my salt water pool (I use a SWCG for chlorination).

Lately, I've been pretty active on this forum learning ways to save money on chemicals.

I've noticed Kem Tek 338 Metal & Calcium Remover is a bit less expensive than Purple Stuff. However, I noticed the Purple Stuff is specifically formulated for salt/high TDS pools (Jack's Magic states it's much more effective than other sequestrants in such conditions); there is no mention of this on the Kem Tek product.

I've emailed Kem Tek, but I can guess what they will say though. While I'm waiting for a response, do any of our experts here know if the Kem Tek product is just as effective as the Purple Stuff in salt/SWCG pools?

Thanks.

PS - As discussed before in another thread of this forum there is a question about whether or not I still need a sequestrant, but I'll save that question for another time once I'm able to conduct an experiment suggested by PoolDoc (Ben).

All the products you mention are HEDP. Kem-Tek is a 20% concentration, but I don't know the concentrations in the Jacks' product. Other than impurities they should be identical . . . IF you can determine concentration.

HEDP was developed by Monsanto as part of their "DeQuest" line. I'm not sure if they still make it; probably most of it is coming from Asia now, as chemical regulations make it extremely difficult to manufacture commodity chemicals profitably here in the US. Asian purities can be suspect, so the question is about quality control, but I doubt you're going to get good answers there.

28 July 2012 update:
HEDP

Jack's Magic Blue Stuff (20% solution)
Jack's Magic Purple Stuff (20% solution)
Jack's Magic Pink Stuff (60% solution)
ProTeam Metal Magic (30% solution)
RamChem Ram Metal Hold ((60% solution? )
Kem-Tek 338-6 Metal & Calcium Eliminator (20% solution)
Haviland Stain & Scale Magic (30% solution? )

Remember, though, manufacturers can change formulations without notice.

Quote:

---

Originally Posted by PoolDoc

All the products you mention are HEDP. Kem-Tek is a 20% concentration, but I don't know the concentrations in the Jacks' product. Other than impurities they should be identical . . . IF you can determine concentration.

HEDP was developed by Monsanto as part of their "DeQuest" line. I'm not sure if they still make it; probably most of it is coming from Asia now, as chemical regulations make it extremely difficult to manufacture commodity chemicals profitably here in the US. Asian purities can be suspect, so the question is about quality control, but I doubt you're going to get good answers there.

---

Thanks Ben. As you well know it's frustrating trying to compare products with the lack of good information from manufacturers. While I was able to find Jack's Magic uses HEDP, like you I was unable to find the concentration.

Do you, or anyone else here (chem geek?), have an idea of how HEDP behaves in a high TDS/salt environment? Is is simply a matter of having a high enough concentration of HEDP to be effective in such an environment?

If you ask in a month, I might. I have Monsanto's Dequest tech bulletins, but what I don't have is time to dig them out right now.

Quote:

---

Originally Posted by PoolDoc

If you ask in a month, I might. I have Monsanto's Dequest tech bulletins, but what I don't have is time to dig them out right now.

---

Thanks Ben. I'll bring up the question again in a month or so.

I still need to get together the materials I need for the bucket test you suggested to see if I still have any metals in my pool. Hopefully I can try it this weekend.

Just one bit of info I had to dig out: "The Pink Stuff" is 60% concentration; "Purple" and "Blue" stuff are both lower, maybe 20%

Quote:

---

Originally Posted by PoolDoc

Just one bit of info I had to dig out: "The Pink Stuff" is 60% concentration; "Purple" and "Blue" stuff are both lower, maybe 20%

---

Thanks Ben.

Interesting. If I had to make a guess (completely uneducated:o), I would have thought the products designed for high TDS/salt pools would have been a higher concentration.

Given the information you found, would you think that the 20% concetration Kem Tek product would be as effective as the Purple Stuff? Could there be something else in the Purple Stuff that makes it work better in a high TDS/salt pool?

I've sent a couple emails to Kem Tek asking about using their product in a high TDS/salt pool, but they have not responded.:(

1. I think you are confusing marketing with design; when product labels say "designed for X" it almost always means "designed to sell TO people with X", and not "designed by a team of engineers for optimal performance when X is present". I'm smirking, as I type this, but I'm perfectly serious in making the assertion.

2. I doubt anyone has actually studied the effect of different concentrations of HEDP in salt water pools.

3. I think 3 cups of the Kem-Tek product would perform identically to 1 cup of the Pink Stuff or 3 cups of the Purple or Blue Stuff.

I thought that the pink and blue stuff were the same strength. I seem to remember seeing that somewhere, either on the bottles themselves of in some of the Jack's Magic Literature. I could be wrong.

Nah.

In the MSDS (unless Jack's has pulled a switcheroo, a la Natural Chemistry), Pink has a specific gravity of 1.48, and the others have a specific gravity of 1.10 or less.

Quote:

---

Originally Posted by waterbear

I thought that the pink and blue stuff were the same strength. I seem to remember seeing that somewhere, either on the bottles themselves of in some of the Jack's Magic Literature. I could be wrong.

---

I took a look at the bottle and there's nothing listing ingredients or concentrations. It's interesting that the dosing instructions for the Pink Stuff and Purple Stuff are exactly the same to reach the same level (10-12ppm).

I did see this on the Purple Stuff bottle in addition to its claims to "remove" metals; "...helps keep silica in solution and helps prevent scaling of cells in salt water chlorine generator systems..." What exactly does this mean? Anything?

Found this on poolgeek.com (where I buy Jack's Magic) about the Purple Stuff; "A concentrated blend of stain preventing and sequesting agents."

And this about the Pink Stuff; "A professional strength blend of sequestering agents."

This seems to point to some difference in strength.

Then there's the Magenta Stuff for salt pools. Instead of HEDP is uses "Acrylic Acid Copolymer". Any idea what this is and it's effectiveness?

Quote:

---

Originally Posted by JimK

Instead of HEDP is uses "Acrylic Acid Copolymer". Any idea what this is and it's effectiveness?

---

PAA - Polyacrylic acid, used to make disposable diapers, among other things. Google for more info.

Quote:

---

Originally Posted by PoolDoc

PAA - Polyacrylic acid, used to make disposable diapers, among other things. Google for more info.

---

I Googled it, found alot of stuff speaking over my head.:confused:

Is it effective?

don't really know.

It's a common ingredient in polymeric clarifiers. Because it has many negatively charged sites on the polymer chains it can 'grab' positively charged molecules and clump them so they can be filtered out more efficiently and can also temporarily bond metal ions such as calcium and magnesium so it has a 'water softening' effect. (This is why it is also added to Clorox bleach and some laundry detergent formulas since the larger "clumps do not redeposit as readily on clothes.)

Does it work? As well as any other polymeric clarifier. Overdosing can cause particles to form a colloidial suspension that is almost impossible to filter out instead of forming larger, filterable "clumps"

Quote:

---

Originally Posted by waterbear

...... Overdosing can cause particles to form a colloidial suspension that is almost impossible to filter out instead of forming larger, filterable "clumps"

---

:eek: Guess I won't be using that.

According the Jack's Magic, one of the benefits of this is that it doesn't add phosphates to the pool like HEDP does. Do phosphates matter in a pool with with borates (I try to maintain 50ppm)?

If you remove nearly all phosphates, algae has a hard time growing.
If you maintain 50+ ppm borates, algae has a harder time growing, though I doubt the effect is as great as with PO4<100 ppb
If you maintain constant chlorination at FC=10% of CYA, as far as we know, algae will not get started, though once established, some algae colonies will persist.

Quote:

---

Originally Posted by PoolDoc

If you remove nearly all phosphates, algae has a hard time growing.
If you maintain 50+ ppm borates, algae has a harder time growing, though I doubt the effect is as great as with PO4<100 ppb
If you maintain constant chlorination at FC=10% of CYA, as far as we know, algae will not get started, though once established, some algae colonies will persist.

---

Great info.:D

While I haven't maintained chlorine at 10% of CYA (I maintain FC 4-5 at 60-80 CYA), I do try to keep borates at 50ppm and add a phosphate remover when closing the pool for the season to keep phosphates down. Since starting this practice many seasons ago I've not had any algae outbreaks. Someone mentioned the phosphate treatment at closing probably wasn't necessary, but I think I'll stick with it since this routine seems to work well for my pool.

Perhaps the combination of low phosphates and the addition of borates is a double wammy for algae. Although I've not tried it yet, I'm thinking I might be able to discontinue the weekly polyquat (60%) doses. Perhaps I'll try that next season since I already have my supply of polyquat for this season.

Also, if the bucket test for metals comes back negative (I'll know tonight), perhaps I can also stop, or greatly reduce, the addition of the sequestrant (Jack's Magic Purple Stuff).

Thanks again for taking the time to help us.:)

Quote:

---

Originally Posted by JimK

.....

Also, if the bucket test for metals comes back negative (I'll know tonight), perhaps I can also stop, or greatly reduce, the addition of the sequestrant (Jack's Magic Purple Stuff).
.......

---

Ben, when I checked the bucket this evening the water was still cloudy from the addition of washing soda. When first I started the test and added the chlorine, the water got cloudy, but cleared the next day (I didn't see any staining or sediments). When I then added the washing soda, it got cloudy again, but this time it has not cleared after more than 24hrs so I cannot see if there are any stains or sediments.

Any suggestions on how to proceed?

Do you have a K-2006 or an HTH 6-way drops kit? If so, what are your calcium and alkalinity levels?

Quote:

---

Originally Posted by PoolDoc

Do you have a K-2006 or an HTH 6-way drops kit? If so, what are your calcium and alkalinity levels?

---

Calcium is about 240, TA is 90-100

Quote:

---

Originally Posted by JimK

Ben, when I checked the bucket this evening the water was still cloudy from the addition of washing soda. When first I started the test and added the chlorine, the water got cloudy, but cleared the next day (I didn't see any staining or sediments). When I then added the washing soda, it got cloudy again, but this time it has not cleared after more than 24hrs so I cannot see if there are any stains or sediments.

Any suggestions on how to proceed?

---

Quote:

---

Originally Posted by PoolDoc

Do you have a K-2006 or an HTH 6-way drops kit? If so, what are your calcium and alkalinity levels?

---

Quote:

---

Originally Posted by JimK

Calcium is about 240, TA is 90-100

---

Hi Ben.

I let the bucket sit another 24 hours and now the water is clear. The only thing I see is white sediment on the bottom of the bucket. What do these results mean? Anything useful?

BTW, a clarification/correction; the calcium level I mentioned above is actually the "Total Hardness" per pool store testing. The TA figure is from my own testing using a Taylor kit (the figure is unadjusted for CYA which is 80 per my own test using Taylor kit). Today I purchased the Taylor reagents needed to test for calcium, but need help with that (see my post in the appropriate section).

Quote:

---

Originally Posted by JimK

Today I purchased the Taylor reagents needed to test for calcium, but need help with that (see my post in the appropriate section).

---

FYI, I answered that post.

Quote:

---

Originally Posted by waterbear

FYI, I answered that post.

---

Thanks. I'll take that conversation over there.:)

Quote:

---

Originally Posted by JimK

Hi Ben.

I let the bucket sit another 24 hours and now the water is clear. The only thing I see is white sediment on the bottom of the bucket. What do these results mean? Anything useful?.....

---

Hi Ben.

I know you are really busy and I greatly appreciate your help with doing the bucket test for metals.

Waterbear helped me with problems I was having reading the Taylor calcium test kit results ( http://www.poolforum.com/pf2/showthr...lcium-test-kit ). I appears my calcium level is 250ppm max.

So to summarize, my TA is at 90-100 (NOT adjusted for a CYA level of 80; don't know what the adjusted level would be) and Calcium is at 250ppm max. After waiting an additional 24hrs. the water in the bucket is now clear with only white sediment visible on the bottom (sides of bucket are also white).

Let me know what you think when you get a chance.:)

You did the bucket test. You added bleach -- to break down any phosphonates, and then oxidize any metals to the insoluble form, and then soda ash, to raise the pH to the point where they would precipitate.

Colors tell the tale: iron would make the sediment brown or orange; copper blue or green, or maybe black. You got tan. That means calcium plus maybe a tiny bit of iron. You *might* have other metals, but it's unlikely.

Quote:

---

Originally Posted by PoolDoc

You did the bucket test. You added bleach -- to break down any phosphonates, and then oxidize any metals to the insoluble form, and then soda ash, to raise the pH to the point where they would precipitate.

Colors tell the tale: iron would make the sediment brown or orange; copper blue or green, or maybe black. You got tan. That means calcium plus maybe a tiny bit of iron. You *might* have other metals, but it's unlikely.

---

Thanks Ben. Actually, the sediment is white. I take this to mean it's not likely I have any metals and that adding the sequest isn't doing anything?

If I wanted to later test for metals using a Taylor kit, how long should I discontinue sequestrant use before testing to be sure the sequestrant doesn't interfere with the results?

Wow. Missed this one.

Yes, white sediment in a metals test strongly suggests no metals are present.

As far as how sequestrants / chelants interact with copper tests (of various flavors), that's information we haven't been able to find yet!

Quote:

---

Originally Posted by PoolDoc

Wow. Missed this one.

Yes, white sediment in a metals test strongly suggests no metals are present.

As far as how sequestrants / chelants interact with copper tests (of various flavors), that's information we haven't been able to find yet!

---

No problem, Ben. I know y'all have been swamped with requests for help this season. I kind of figured that if tan sediment meant a small amount of iron, that white sediment like I got meant no metals.

I'd still like to discuss and get a better understanding of what happened to the metals that I did have in my pool, but since I'm not currently having any issues that discussion can wait until after the end of the busy season. I look forward to that discussion.:)

Thanks.