💧 Which Pool Chemicals Need to Be Dissolved Before Adding to Your Pool?

When adding pool chemicals, knowing which ones require pre-dissolving (and which don’t) is critical for protecting your pool surface, your equipment, and even your swimmers. Dumping certain chemicals directly into the pool—especially granular types—can cause staining, cloudy water, or surface damage.

In this blog post, we’ll break down exactly which chemicals should be dissolved in water first, and why it matters for proper pool care.

🧪 Why Pre-Dissolve Pool Chemicals?

Some pool chemicals are highly concentrated in granular form, and if added directly, they can:

Settle on the bottom and bleach or stain surfaces

Damage vinyl liners or plaster

Lead to uneven distribution and poor water chemistry

Cause cloudiness or scaling

Pre-dissolving ensures even mixing and safe application.

✅ Chemicals That Should Be Pre-Dissolved

1. Calcium Hypochlorite (Cal-Hypo Shock)

Why? It’s highly reactive and can settle or bleach your pool surface.

How: Mix in a clean plastic bucket with pool water before pouring around the perimeter.

Tip: Only mix what you’ll use immediately. Never store pre-dissolved shock.

2. Calcium Hardness Increaser (Calcium Chloride)

Why? Can cause scaling and cloudy water if added too quickly.

How: Slowly add to a bucket of water, stir until fully dissolved, then pour in.

Warning: Water first, then chemical—never the reverse to avoid heat reaction.

3. Soda Ash (pH Increaser)

Why? May cloud water or clump if added directly.

How: Dissolve in warm water before adding to the deep end while the pump is running.

4. Alkalinity Increaser (Baking Soda or Sodium Bicarbonate)

Why? Not always required, but recommended for better dispersion in large doses.

How: Pre-dissolve in a bucket and pour around the pool while circulating.

5. Pool Flocculants (Floc)

Why? Most require mixing in water before pouring to work effectively.

How: Follow manufacturer instructions carefully—some are pour-in, others need dilution.

🚫 Chemicals You Can Add Directly to the Pool

Not all chemicals need pre-dissolving. These are usually safe to add directly while the pump is running:

Liquid chlorine/bleach

Muriatic acid (though diluting in water can help prevent local pH shock)

pH reducers (dry acid/sodium bisulfate) (some brands recommend dissolving, but many are fine when broadcasted evenly)

Stabilizer (CYA) in skimmer sock method (but avoid direct broadcast—can sit undissolved for days)

Algaecides

Enzymes and clarifiers

Pool Salt

🧼 Pro Tips for Safe Chemical Mixing

Always add chemical to water, not the other way around.

Use clean, chemical-safe plastic buckets—never metal.

Wear gloves and goggles, especially with strong oxidizers.

Never mix different chemicals in the same bucket.

Store chemicals in a cool, dry, well-ventilated area.

🏊 Final Thoughts

Knowing which pool chemicals need to be pre-dissolved isn't just about efficiency—it's about protecting your pool and your investment. When in doubt, read the label or consult a pool pro.

Need help finding the right treatment for your water? Stop by our store or contact us online for expert guidance—and all the pool chemicals you need to keep your water crystal clear.

https://justthepoolpeople.com/