2 questions for new plaster start-up

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Uncle Ben

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Apr 20, 2010
83
Southern California
1. What is the "sequestrant" that is to be added at the beginning of start up? Is that the actual name of the chemical that I would ask for at the pool store? (I assume the bottle will say how much to add per 1,000 gallons...)

2. Is it okay to be adding new DE to my filter each time I clean the grids during start up as psi raises due to the plaster dust in the filter?

I just want to make sure any possible DE in the water will not harm the new plaster, but I assume the filter will be pretty useless if there is no DE on the grids.

Thanks!
 
The sequestrant is a common requirement in pool builder paperwork. Some "require" it in order to preserve the warranty and some only "suggest" it. If you're sure you don't have metals AND it's not "required" for warranty, you don't need to add it. Jacks magic is a well liked brand.

You should be adding DE after each backwash. You should add about 80% of a full charge each time.
 
It keeps metals in the water in solution so they don't stain. Warranties don't cover staining and enough people have metals in their water and they've had enough complaints that it's become a standard recommendation.

As I said, if you don't have metals then it's a useless expense.
 
New plaster needs about a full month to cure, right? So does that mean no one should swim in the pool until curing is done?

In the start-up procedure it says to add "chlorine SLOWLY to gradually bring it to the desired level". Does that mean I need to add a little each day over a few days, or add a little at a time perhaps over just one day until it is where I need it?

Also, the pool just finished filling overnight, so I turned on the pump before leaving for work this morning, since it is supposed to run 24 hrs a day for the first week, BUT there was a lot of nasty dark water still in the lines from before the re-plaster, which is now in the water. Could this stain the new plaster surface very quickly, or will it be okay since the pump is running and can filter back through? Just wondering if I should rush back home to do something about it before I create staining. (I realized after that I should have backwashed first!)
 
Plaster takes years to fully cure, but the majority of the curing happens in the first month. Absolutely do not swim for 24 hours after plaster is applied and also not until there is a measurable FC level. I would wait a week, but many people don't.

Do not add chlorine during the first 48 hours. After that, the best way to startup a new plaster pool is with trichlor tablets. They add chlorine and CYA slowly and constantly, both of which you need, and also help keep the PH down. As long as the pump is running 24/7 you can put trichlor tablets in the skimmer basket if you don't have a tablet feeder. If adding chlorine manually you need to be very gradual for the first couple of days, which means several small additions each day.

Ordinary dirt is not generally an issue, but metals in the water can be a serious problem. The filter and brushing will take care of any dirt. If there is any risk of metals either in the dirt or the fill water you should use some sequestrant during startup. Metals in the water can interact with the plaster as it cures and form permanent stains (not removable by the usual techniques).
 
Another question for you:
Two nights ago I had pH at about 8.3 (that is my estimate since the scale on the tester only goes to 8.2 and it was a little darker than that) so for my size pool and using the pool calculator I added 70oz of 15% acid to bring it down to 7.4

Last night I checked the pH again and and it was exactly the same as the preivous night, as if I had added nothing. Is that normal?

I did read somewhere on here that a lot of acid is consumed for a new plaster startup, but this has me a little worried since if the pH is able to climb that quickly it could cause damage to the new surface until I'm able to test and add acid the next day.

Thanks.
 
Yes, it is normal for the PH to go up very rapidly during the first three or four weeks. In some cases you even need to add acid twice a day, though usually all you need to do is add more acid each time you add acid.

It is important to keep the PH under control during this period. If the PH gets too high you can have calcium scaling which can look bad and cause a rough pool surface.
 

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Bama Rambler said:
The sequestrant is a common requirement in pool builder paperwork. Some "require" it in order to preserve the warranty and some only "suggest" it. If you're sure you don't have metals AND it's not "required" for warranty, you don't need to add it. Jacks magic is a well liked brand.

You should be adding DE after each backwash. You should add about 80% of a full charge each time.
Click to expand...

80% is right if "backwashing". Ben said he was "cleaning" the filters, so Ben wants to put 100% of the DE back in?

New plaster needs a nylon brush only for how long? Ben can start w a nylon-metal-combo brush when?
 
I do plan to backwash, hopefully for the rest of the season, but I had not opened up the filter for a true cleaning since I took ownership of the pool last season, so it was really quite overdue.

As far as the acid, I noticed last night on the instructions on the box that it says to not add more than one quart per 10k gallons per 24 hours, but it's impossible for me not to do so, since my 12k gallon pool calls for around 70oz (of 14.5% MA) to get the PH from 8.2 down to 7.4, and then it's already way to high again by the next time I check it. Am I really risking damage by adding that much at once?
 
Great, thanks!

Also, it appears that I do have metals in the water (iron and copper). It was suggested to try Jacks Magic sequestrant, but I can't find it locally. Leslies has "metal free" with the following description, and I wanted to see if this is the same thing, or will substitute okay...
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"Metal Free deactivates metals (iron, copper, other trace metals) quickly and easily to prevent stains and water discoloration, chelating metals without raising phosphate levels in your pool, which have been proven to increase algae production. Metal Free contains one of the strongest and most effective chelating agents available and is made from all natural ingredients so it will not harm any natural vegetation or landscaping. It is not affected by pH or temperature fluctuations. For best results use Metal Free each spring or as water is added to your pool.

Initial Dosage: 1 liter treats 20,000 gallons
 
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