In The Swim Alkalinity Increaser for Swimming Pools - Raises Alkalinity and Balances pH Levels in Your Swimming Pool Water - 100% Sodium Bicarbonate - 25 Pounds
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Availability:
In Stock.
Arrives
Tuesday, May 19
Style: Alk Incr
Size: 25 Pound
Features
- In Swim Alkalinity Increaser maintains pH and chlorine levels.
- Prevents pH swings, maintaining stable water chemistry.
- High pH causes skin rashes; low pH stings eyes.
- Ensures refreshing pool water, even in hot summers.
- Maintain alkalinity at 90-120 ppm. Add 1.5 lbs per 10,000 gallons to increase by 10 ppm.
Brand: In The Swim
Item Weight: 27 Pounds
Item Form: Granular
Product Benefits: Protects Against Skin Irritation
UPC:
Brand Name: In The Swim
UPC: 803354120857
Number of Items: 1
Unit Count: 400 Ounce
Model Number: Y7320
Manufacturer Part Number: Y7320
Manufacturer: In The Swim Discount Pool Supplies
Item Form: Granular
Product Benefits: Protects Against Skin Irritation
Item Weight: 27 Pounds
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Tuesday, May 19
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Similar Products
Top Amazon Reviews
Style: Alk Incr
Size: 50 Pound
This alkalinity increaser is 100 percent sodium bicarbonate, the exact same chemical used in other alkalinity increasers (it is baking soda). As with many other chemicals required for pool maintenance, Amazon has a significant discount over those found at your local pool supply store. This product is about 12-13 percent less, from what I have observed. This product is packaged with an internal bag that is closed with a plastic clip (looks exactly like an oversized clip used on bread bags). This makes it a little difficult to pour out as the bag tends to slip out of the bucket. If you are not careful you could end up with the entire bag in your pool. Once about half of the bag is used, I've found it easier to simply empty the bag into the bucket and discard the bag. The bag tends to slide out more when there is less product left in it and when it's full it's too difficult to lift out of the bucket to invert it to pour it out. There is a dosage chart on the back. The chart goes up to a 50,000-gallon pool size. This is nice, as most charts on pool chemicals stop at a lower size. I have a larger pool so with this chart I can directly read the dosage, saving an extra math step (and a potential source of error). As with all alkalinity increaser, this will slightly raise your pH level. And adding acid to lower the pH can lower the alkalinity, so it can take a little back and forth to get both balanced. My best advice for this is, first, test your pool often and try not to let the levels drift too far outside of the desired range. The further they are out of range, the more difficult it is to get them back. Second, add only one chemical at a time (alkalinity increaser or acid) and leave at least 24 hours between adding them. It can be tempting to add a little extra alkalinity increaser since you will probably have to add acid to lower the pH afterwards, but it is not recommended to do this unless you know exactly what you are doing (if you get the alkalinity too high, you will have to try to lower it). Best to add a little less than needed, wait 24 hours, retest, and add more if needed. Works just as any other alkalinity increaser. The staff at the local pool store recommends pouring the required amount (see the back for dosage recommendations) in one location (i.e., do not "broadcast" it or spread it around the perimeter of the pool). They claim this is the best way to increase the alkalinity without increasing the pH. When adding acid, they told me to do the opposite, broadcast it around the perimeter spreading it out as much as possible. They claim this is the best way to lower the pH without also lowering the alkalinity. I'm not sure about the validity of this since I am not a chemist. However, I do know the workers at the pool store are also not chemists so I am more than mildly suspicious this is either an old wives' tale or anecdotal at best.
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Reviewed in the United States on January 14, 2016 by Lance A. Endres
Style: Alk Incr
Size: 25 Pound
Great price and does the job.
Reviewed in the United States on August 10, 2025 by Krista Thompson
Style: Alk Incr
Size: 25 Pound
Good product
Reviewed in the United States on October 26, 2025 by Wii Man
Style: Alk Incr
Size: 50 Pound
Works really well but I paid way too much. It's basically $1.60 a pound.
Reviewed in the United States on June 26, 2025 by Sammy Conway
Style: Alk Incr
Size: 50 Pound
Great product, bought multiple times.
Reviewed in the United States on April 6, 2026 by Crystal Real
Style: Alk Incr
Size: 25 Pound
Just great
Reviewed in the United States on April 16, 2026 by puddles
Style: Alk Incr
Size: 50 Pound
Great
Reviewed in the United States on March 18, 2026 by Devashish ray
Style: Alk Incr
Size: 50 Pound
Why did you pick this product vs others?: Cheaper than the pool store and works just as well
Reviewed in the United States on July 14, 2025 by Bill Long