How to use 50% strength ATMP

Jump to latest Follow Reply
mjthompson01

mjthompson01

0
Nov 20, 2016
2
Stanwood
Hi all,

Anyone have any insight regarding appropriate dosing levels using 50% strength ATMP. I came across 5 gal of it, unopened. Not sure how old it is but everything I have read says it is long term stable. I am on a well with a water softener system that works quite well. I am looking for helpful information for a good dose amount and frequency. The pool is indoor, 20x50 feet, old, plaster - no rock and around 50K gallons at 86 degrees f. I have managed to keep my saturation index around -0.2. The pool sat unused for a few years before we bought the place so we inherited some wonderful metal stains. The stains are stable but I have been busting the bank for sequestering agents. It would be nice if they did not get any worse.

Currently changing over to a salt water system but have not yet added the salt.


FC 2.5
CC 0
pH 7.4
TA 120
CH 300
Cya 40

Thanks in advance for your knowledge and help.

Mike
 
Greetings, Mike, and welcome to TFP. Metals are something of an advanced topic in these parts, so bear with me ;) I will have some questions!

First, I want to express possible caution about using ATMP in your pool based on the MSDS:
https://www.spectrumchemical.com/MSDS/ZQ035.pdf

While it is indeed a type of phosphonic acid, it is not, I believe, the HEDP type normally formulated for pool use and normally advocated by TFP in products such as Jack's Magic, or my fav, Metal Magic. Alternately, I may just not be familiar enough with the formulation ;)

The handling cautions in the MSDS are way more concerning than the msds of the HEDP type formulations.

Joyful Noise will likely have the chemistry background to identify any contraindications, etc. if same exist, and I will send him a note in the hope that he's able to check in.

In the mean time, can you fill us in a little more on your current sanitization and testing methods, the ppm of iron you're treating if you know, and what treatments you've tried to date - eg. Ascorbic Acid, while a bit of a pita to do, might be a treatment that remedies the stain, and depending on brand and quantity used, just switching sequestrants may help.

Rate of sequestrant dosing also ties to degree of metal concentration. Any time source water is in the neighborhood of 2 ppm, you can count on a heftier diet.

To cover the basics, are your reading from a FAS/DPD kit that you own and are comfortable using?
(Update - I now see your sig, so yes...)
Have you read the [fc/cya][/FC/cya] to get the founding principle of the TFP method of sanitation?

What brand of sequestrant have you used to date?

Is your soft water plumbed to your fill?

Have you done the vitamin c test on the stains? Eg, crushed up vitamin c to confirm immediate lightening? - That would indicate iron. With copper staining, it might instead turn black, then lift a bit, or just stay blackish in color.

Could you post a pic of the stains?

I know, lots of questions when you sought a simple answer, but it will help us give the best advice ;)
 
PS - in terms of dosing, for those who have sequestrant test kits (rare, expensive), HEDP such as Jacks is about 12 ppm...more effect doing (eg my pool on well with Metal Magic) is more like 25 ppm.

For industrial cooling tower use, by comparison, ATMP seems to 20-60 ppm.
 
You want to dose it the same way you would dose HEDP - 10-15ppm is the standard maintenance dose and a typical starting dose is to go as high as 25-30ppm. In a pool your size you will need a lot of this stuff (just as much as any HEDP product you're purchasing right now) and I'm not sure at all WHY you want to use this in your pool long term? If you have stains, you need to find the source of the metal contaminant and remove it. You might need to remove the current stains you have and then drain the pool water and refill with metal free water.

There is a downside to using ATMP. It's a scale inhibitor that contains an amine in the backbone. As chlorine oxidizes it, it can possibly form chloramines so you could be seeing a rise in CC levels. HEDP doesn't do this because it has no amine group in it; it decomposes into carbonates and phosphates. ATMP is typically used in boiler water and cooling tower applications where the water has no chlorine in it. It's not typically used in swimming pools.
 
JamesW said:
http://plasticapools.net/media/datasheets/SDS056-Conc-Stain-and-scale-inhibitor-English.pdf

6 x 1lt Relax Concentrated Stain and Scale available from Plastica Ltd - Independent Trade Supplier Manufacturer of Swimming Pool Products

Here is one product for pool use.
Click to expand...

Darn Limey's!! Always adding weird stuff to their pools....

Looks like they add phosphorous acid (not to be confused with phosphoric acid) to act as a strong reducing agent. The phosphorous acid would cause the deposited metal oxide stains to go back into solution and then the ATMP would chelate it....still, not your typical stain and scale remover found in the US. I don't know the relative costs of HEDP versus ATMP but I bet there's a good financial reason why everything here is HEDP.
 
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply