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

[JimK]

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).

[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.

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.

[JimK]

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?

[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.

[JimK]

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.

[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%

[JimK]

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), 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.

[PoolDoc]

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.

[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.

[PoolDoc]

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.