HTH™ Pool Care Calcium Up

Pool Calcium Hardness Increaser

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

HTH™ Pool Care Calcium Up

Pool Calcium Hardness Increaser

HTH™ Calcium Up is a pool hardness increaser that raises calcium hardness back into the recommended 200-400 ppm range. It prevents corrosive water from damaging your pool.

  • Prevents soft water from etching plaster and damaging surfaces
  • Target range: 200-400 ppm
  • Fast-dissolving granules broadcast easily with pump running
  • Never add more than 10 lbs per 10,000 gallons at one time

Product Benefits

Prevents Costly Surface Damage

When calcium hardness drops below 200 ppm, soft water aggressively pulls calcium from pool plaster. This causes etching, pitting, and rough surfaces over time. This damage is permanent and expensive to repair. Keeping calcium at 200-400 ppm protects your investment.

Protects Pool Equipment

Soft water also corrodes metal components in heaters, pumps, and filters. Vinyl liners fare better than plaster but still benefit from proper calcium hardness. Plaster and concrete pools perform best at the higher end of the range (250-350 ppm), while vinyl and fiberglass pools can run a bit lower.

Fast-Dissolving Granules

Broadcast evenly across the pool surface with the pump running. Brush any settled material to help it dissolve. For large increases (more than 50 ppm), add no more than one-third of the dose at a time. Wait 4-6 hours between additions to avoid clouding the water.

Works in Every Pool Type

Safe for vinyl-lined, fiberglass, concrete, and saltwater pools. Maintain proper calcium hardness to protect every type of pool from the effects of corrosive, unbalanced water.

How to Use

Product Purpose

HTH Calcium Up is designed to raise calcium hardness levels in pool water, prevent corrosion of pool surfaces, and protect pool lining.

Testing and Application

Before Application: - Test your pool water’s calcium hardness level - Maintain proper balance of pH, chlorine, and alkalinity alongside calcium hardness

How to Use

  1. Measure the calcium hardness of the pool water with an HTH test kit or test strips.
  2. Broadcast evenly over the pool surface with the pump running. Brush any settled material to ensure it gets dissolved.
  3. If a large amount of HTH Pool Care Calcium Up is required (an increase of more than 50 ppm calcium hardness), add 1/3 of the appropriate dose per addition. Wait 4–6 hours between additions.
  4. Use the chart below to determine the amount ofHTH Pool Care Calcium Up.

Dosage Guidelines:

Pool Volume
(Gallons)		 Lb to Raise Calcium Hardness (ppm)
20 ppm 60 ppm 100 ppm 140 ppm
1,000 0.2 0.6 1 1.4
2,000 0.4 1.2 2.0 2.8
5,000 1 3 5 7
10,000 2 6 10 14
30,000 6 18 30 42

Ingredients

Active Ingredients

Calcium-based compound (specific formulation details provided on product packaging)

Safety, Storage, and Disposal

Safety

Warning: Contains calcium chloride. Causes eye irritation. May cause skin irritation. Avoid contact with eyes, skin, and clothing. Harmful if swallowed. Inhalation of dust may irritate the respiratory passages. Avoid breathing dust.

Wash hands thoroughly after handling. Do not mix with other chemicals.

First Aid

If in Eyes: Hold eye open and rinse slowly and gently with water for 15–20 minutes. Call a poison control center or doctor for treatment advice.

If on Skin or Clothing: Take off contaminated clothing. Rinse skin immediately with plenty of water for 15–20 minutes. Call a poison control center or doctor for treatment advice.

If Swallowed: Call a poison control center or doctor immediately for treatment advice. Have person sip a glass of water if able to swallow. Do not induce vomiting unless told to do so by a poison control center or doctor. Do not give anything by mouth to an unconscious person.

If Inhaled: Move person to fresh air. If person is not breathing, call 911 or an ambulance, then give artificial respiration, preferably by mouth‑to‑mouth if possible. Call a poison control center or doctor for further treatment advice.

In case of emergency, call 1‑800‑654‑6911. Have the product container or label with you when calling a poison control center or doctor.

Storage and Disposal

Keep this product in its original, tightly closed container in a cool, dry, well‑ventilated area when not in use. Use entire contents, then triple rinse and offer for recycling, or dispose in accordance with state and local regulations.

Do not reuse empty container.

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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