What is a sequestrant?

[RawhideKid]

Split into a new topic. If you hate to hijack then don't. JasonLion

Ok...hate to hijack the thread, but what is a sequestrant? Can't find it defined in the pool school area (abbreviations and definitions area) , common chemicals, etc. Even the "start up" procedures for a plaster pool recommend early on to add a sequestrant, but what is a recommended one, and how much of it should I add?

confused as usual....

 

[chem geek]

Re: New Saltwater Pool, proper birthing order?

Ok...hate to hijack the thread, but what is a sequestrant?

See Metals in the Water and Metal Stains in the Pool School. A metal sequestrant holds onto metals to prevent them from staining pool surfaces. It's only needed if you've got metals (iron, copper, manganese) in your water, such as sometimes occurs in well water.

 

[NWMNMom]

Re: New Saltwater Pool, proper birthing order?

Always be sure it is added BEFORE chlorine or it will oxidize the iron in the water and look like chocolate! First hand experience.

 

[RawhideKid]

Re: New Saltwater Pool, proper birthing order?

Ok...hate to hijack the thread, but what is a sequestrant?

See Metals in the Water and Metal Stains in the Pool School. A metal sequestrant holds onto metals to prevent them from staining pool surfaces. It's only needed if you've got metals (iron, copper, manganese) in your water, such as sometimes occurs in well water.

Ok - just read that link. How do you know if you have metals in your water - other than waiting for the stains to appear... :|

and, if you are going to add a sequestrant to the water BEFORE chlorine (thx NWMNMom), how long do you wait to add chlorine after you put the sequestrant in? Hours? Days? I like chocolate, but, er, not in my pool....

 

[JasonLion]

If you don't current have any reason to believe there are metals in the water then assume there aren't.

Wait about four hours after adding sequestrant before doing anything that will raise PH or FC.

 

[RawhideKid]

If you don't current have any reason to believe there are metals in the water then assume there aren't.

Wait about four hours after adding sequestrant before doing anything that will raise PH or FC.

Thanks Jason - you might want to adjust the plaster startup discussion as it seems to recommend sequestrant as part of the plaster pool start up procedure: pool-school/pool_plaster_start-up

Given we have city water, and i've not heard of metals being an issue, we should be ok. Sorry to pick some nits, but i'd hate to have metal stains in my new (!) pool!

 

[JasonLion]

For a fresh plaster startup you should add a sequestrant optimized for calcium even if there are no metals at all. There are two reasons for this. First, calcium is technically a metal, and sequestrant will help prevent calcium scaling, which is a big risk during a fresh plaster start up. And second, metals stains in the first week become permanently embedded in the plaster and can not be removed. Because of that you want to make extra sure even if the test were to show zero metals.

 

[RawhideKid]

For a fresh plaster startup you should add a sequestrant optimized for calcium even if there are no metals at all. There are two reasons for this. First, calcium is technically a metal, and sequestrant will help prevent calcium scaling, which is a big risk during a fresh plaster start up. And second, metals stains in the first week become permanently embedded in the plaster and can not be removed. Because of that you want to make extra sure even if the test were to show zero metals.

Ah. Ok. Now I get it. Thanks!