member's mark chlorinating granules, 40 lbs front-facing white plastic bucket with blue lid and large blue label showing Member's Mark logo, “Chlorinating Granules” text, Step 2 badge, warning text noting corrosive and keep out of reach of children, and net weight 40 lbs; suitable for use in pools, spas and hot tubs as a sanitizer and shock.
Member's Mark Chlorinating Granules, 40 lbs
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Member's Mark

Member's Mark Chlorinating Granules, 40 lbs

|3,836 ratings
Item # 990394724

Highlights

  • Weight: 40 lb
  • Item Form: Granules
  • Active Ingredient: Sodium dichloro-s-triazinetrione
  • Solubility: Completely soluble
  • Shelf Life: 2 years
  • Dimensions: 14 x 14 x 15 in
  • Member's Mark™ Chlorinating Granules - Step 2 for pool and spa chlorination
  • Ideal for use in swimming pools, spas, and hot tubs
  • Sanitizes water; add directly to circulating water to raise free available chlorine to 5-6 ppm (mg/L)
  • 3-in-1 use: sanitizer, algaecide, and shock for routine care or when water needs attention
  • Filler-free, completely soluble granules to help avoid unwanted residue
  • Active ingredient: Sodium dichloro-s-triazinetrione dihydrate
  • 2-year shelf life
  • Warning: Corrosive; causes irreversible eye damage and skin burns; harmful if swallowed; keep out of reach of children

Specifications

  • Dimensions: 14" x 14" x 15"
  • Weight: 40 lbs
  • pH Level: 6.0 - 8.0
  • Formulation Type: Granules
  • Active Ingredients: Sodium dichloro-s-triazinetrione dihydrate
  • Solubility: Completely soluble
  • Shelf Life: 2 years
  • Intended Use: Swimming pools, spas, and hot tubs
  • Application: Direct application to circulating water
  • Target Free Available Chlorine Level: 5-6 ppm (mg/L)
  • Primary Functions: Sanitizer, algaecide, and shock
  • Formula: Filler-free
Current price is $189.98
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About this item

Product details

Member's Mark® Chlorinating Granules are a filler-free, completely soluble chlorinating granular formula that helps keep pool and spa water clean and fresh with a fast, measurable free chlorine boost.

Three-in-One Pool Care: Sanitizer, Algaecide, and Shock

This Step 2 treatment is a versatile option for ongoing water care and periodic treatment. It functions as a sanitizer, algaecide, and shock in one product to support clean, clear water.

  • Apply directly to circulating water to raise the free available chlorine level to 5-6 ppm (mg/L).
  • Works as an algaecide and shock to help address water that needs attention.
  • The formula is intended to help reduce chlorine odor as part of regular pool and spa maintenance.
  • Listed pH level range: 6.0 - 8.0.

Filler-Free Granules That Dissolve Completely

The filler-free formula means the product is made without added fillers that can contribute to unwanted residue. The granules dissolve completely for efficient distribution in circulating water.

  • Active ingredient: sodium dichloro-s-triazinetrione dihydrate.
  • Formulation type: granules (completely soluble).

Made for Pools, Spas, and Hot Tubs

Ideal for swimming pools, spas, and hot tubs, these granules offer a convenient single treatment to keep on hand for multiple backyard water features.

  • 40 lb size for regular pool and spa routines.
  • Shelf life: 2 years (when stored properly).

Important Safety Information

  • Warning: Corrosive.
  • Causes irreversible eye damage and skin burns.
  • Harmful if swallowed.
  • Keep out of reach of children.

Frequently Asked Questions

What is Member's Mark Chlorinating Granules used for?

It’s for pool and spa water care and is described as a 3‑in‑1 product that acts as a sanitizer, algaecide, and shock.

Can I use Member's Mark Chlorinating Granules in a swimming pool, spa, or hot tub?

It’s ideal for use in swimming pools, spas, and hot tubs, and is designed to be compatible with most pools and spas.

What is the active ingredient in Member's Mark Chlorinating Granules?

Sodium dichloro-s-triazinetrione dihydrate.

Are these chlorinating granules soluble in water?

They are completely soluble.

What free available chlorine level does direct application target?

Direct application to circulating water raises free available chlorine to 5–6 ppm (mg/L).

Is Member's Mark Chlorinating Granules filler-free?

They’re described as entirely filler-free, intended to help avoid unwanted residue.

Does it affect pH or chlorine odor?

The product description says it reduces pH levels and eliminates chlorine odor.

What safety warnings apply to this product?

Corrosive; causes irreversible eye damage and skin burns; harmful if swallowed; keep out of reach of children.

What’s the shelf life of Member's Mark Chlorinating Granules?

Shelf life is 2 years.

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Specifications

  • Dimensions: 14" x 14" x 15"
  • Weight: 40 lbs
  • pH Level: 6.0 - 8.0
  • Formulation Type: Granules
  • Active Ingredients: Sodium dichloro-s-triazinetrione dihydrate
  • Solubility: Completely soluble
  • Shelf Life: 2 years
  • Intended Use: Swimming pools, spas, and hot tubs
  • Application: Direct application to circulating water
  • Target Free Available Chlorine Level: 5-6 ppm (mg/L)
  • Primary Functions: Sanitizer, algaecide, and shock
  • Formula: Filler-free

Member ratings & reviews

4.7 out of 5 stars
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3,836 ratings823 reviews
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  1. 5 stars86% (3,293)
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  3. 3 stars3% (102)
  4. 2 stars1% (51)
  5. 1 star3% (98)
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Showing 1-3 of 823 reviews

Oct 15, 2025
Reviewer name: betty
5 out of 5 stars
5 out of 5 stars review

Verified Purchase

lower the regular price.

Better price! Chlorine has gotten so expensive. There is no real reason for that now the plants are up and running. Sam's club needs to sell it at 79.99 regular price.

Helpful?30FFO4C17W7N15359760490
Jun 25, 2025
Reviewer name: Mike
5 out of 5 stars
5 out of 5 stars review

Verified Purchase

Loving this product better than others I have used

Since purchasing our pool, I have been purchasing the 1 pound packs of shock from an online retailer. I’ve been putting one or two of those in each time that I treat the pool. This year, I was not able to get that delivered so I purchased this product from Sam’s Club. I was amazed to find out that just 4 ounces covers a 10,000 gallon pool. That means this product is much cheaper than the 1 pound bags I was purchasing because of its concentration. The pool has been very clear since I began using this. I am so thankful for shortages and inconveniences.

Helpful?30FFO4C17W7N15359760490
Aug 27, 2025
Reviewer name: Sim
5 out of 5 stars
5 out of 5 stars review

Verified Purchase

Good product but too costly

I have been using this product for years, it keeps my pool's balanced and clean with less maintenance. However, what I'm only disappointed is the cost which doubled in the past three years, the inflation made me sick !!! Hope the price is brought down soon.

Helpful?30FFO4C17W7N15359760490
Current price is $189.98
Prices may vary in club and online
How do you want your item?

Shipping

Free for Plus on eligible orders over $50
Columbus, 43215
Return or replace anytime.

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