HTH™ Pool Care Alkalinity Up

Pool Alkalinity Increaser

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  • Child on a red and white inner tube in a pool with HTH Pool Care branding.

HTH™ Pool Care Alkalinity Up

Pool Alkalinity Increaser

HTH™ Pool Care Alkalinity Up is a pool alkalinity increaser that raises total alkalinity into the recommended 80-120 ppm range to stabilize pH.

  • Fixes the root cause of pH swings: low total alkalinity
  • Target range: 80-120 ppm
  • Add with the pump running, retest after 6-8 hours of circulation
  • Protects pool surfaces and equipment from corrosion
  • Safe for vinyl-lined, concrete, fiberglass, and saltwater pools

Product Benefits

Stops Constant pH Swings

If you keep adjusting pool pH and it keeps drifting back, low total alkalinity is almost always the cause. Total alkalinity acts as a buffer that holds pH steady. When it drops below 80 ppm, rain, swimmers, and routine chemical additions push pH around quickly. Raising alkalinity first is what makes pH adjustments actually stick.

Protects Pool Surfaces and Equipment

Low alkalinity makes water corrosive, which etches plaster, damages vinyl liners, and corrodes metal components in pumps, filters, and heaters. Maintaining 80-120 ppm extends the life of every part of your pool system.

Improves Chlorine Performance

When alkalinity is balanced, pH stays in the ideal 7.2-7.6 range, which is where chlorine works most efficiently. Pools with low alkalinity often consume more chlorine because the sanitizer can't perform at its best when pH is unstable.

Compatible With All Pool Types

Safe for vinyl-lined, concrete, fiberglass, and saltwater pools. Salt chlorine generator pools still need balanced alkalinity to function properly. Add directly to the pool with the pump running and retest after 6-8 hours of circulation.

How to Use

Testing Requirements

Test pool water with HTH™ 6-way Test Strips for total alkalinity level before application. Ideal range: 80-120 ppm.

How to Use

For the Best Results: Keep the total alkalinity at 60–120 parts per million (ppm).

  1. Measure total alkalinity of pool water with an HTH test kit or test strips.
  2. If the alkalinity is below 60 parts per million (ppm), add this product.
  3. Broadcast evenly over the pool surface.
  4. Use the table below to determine the correct dosage.

Dosage Guidelines

  • Refer to the product label for dosage guidelines.
  • Dosage varies based on pool size and desired alkalinity increase

Ingredients

Active Ingredient

  • Sodium Bicarbonate - 100%

Classification

CAUTION - Handle with care

Safety, Storage, and Disposal

Safety Precautions

  • Do not mix with other chemicals
  • Use proper personal protective equipment when handling
  • Keep out of reach of children
  • Avoid contact with eyes and skin

First Aid

  • Eye Contact: Flush with water for 15 minutes
  • If Swallowed: Drink large quantities of water and call a physician

Storage and Disposal

Store in a tightly closed container in a cool place. Use entire contents, then triple rinse and offer for recycling, or dispose in accordance with state and local regulations. Do not reuse empty container.

Emergency Handling

  • Keep out of reach of children
  • In case of eye contact, flush with water for 15 minutes
  • If swallowed, drink large quantities of water and call physician immediately

Frequently Asked Questions

  • What does Alkalinity Increaser do for my pool?

    HTH™ alkalinity increaser raises total alkalinity in pool water to the ideal range of 80–120 ppm, helping stabilize pH so it stops fluctuating. Balanced alkalinity protects pool surfaces, equipment, and swimmers from the effects of corrosive water.

  • When should I add alkalinity increaser to my pool?

    Add HTH™ alkalinity increaser when your total alkalinity tests below 80 ppm. Low alkalinity causes pH to fluctuate erratically, which can lead to chlorine loss, skin irritation, and damage to pool surfaces and equipment.

  • Why does my pool pH keep changing even after I adjust it?

    Unstable pH is almost always caused by low total alkalinity. Alkalinity acts as a buffer that holds pH steady — when it is too low, even small amounts of rain, swimmers, or chemicals can push pH up or down quickly. Raise alkalinity first, then adjust pH.

  • What is the ideal total alkalinity level for a pool?

    The ideal total alkalinity range is 80–120 ppm for most pools. Staying within this range helps keep pH stable, allows chlorine to work efficiently, and helps prevent corrosion or scaling on pool surfaces.

  • How do I use Alkalinity Increaser?

    With the pump running, add the recommended amount of HTH™ pool alkalinity increaser directly into the pool. Retest after 6–8 hours of circulation and repeat if needed until alkalinity reaches 80–120 ppm.

  • Can I use alkalinity increaser in a saltwater pool?

    Yes. HTH™ Alkalinity Increaser is compatible with all pool types including saltwater, vinyl-liner, and concrete pools. Salt chlorine generators still require balanced alkalinity to function properly.

  • What happens if pool alkalinity is too low?

    Low alkalinity (below 80 ppm) leads to rapid pH swings, corrosion of metal equipment and pool surfaces, eye and skin irritation, and faster chlorine consumption. Test and correct alkalinity before adjusting pH or adding other chemicals.

  • What happens if pool alkalinity is too high?

    High alkalinity (above 120 ppm) can cause pH to rise and resist correction, leading to cloudy water, scaling on surfaces and equipment, and reduced chlorine efficiency. If alkalinity is above 120 ppm, use HTH™ pool pH Decreaser to bring it back into range.

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Quick Pool Tips

  • Always read product label directions prior to using and use only as directed

  • Always add chemicals to pool water, never the other way around

  • Never add chemicals to pool water when people are in the pool

  • Warning symbol with a triangle and exclamation mark on a blue background

    Never mix products together

  • Always store pool products in a cool, dry location and out of direct sunlight