So last summer I noticed my pool water looked kinda dull no matter how much chlorine I added. Test strips showed pH bouncing around like a ping pong ball. That's when my neighbor Mike, who's had a pool for 20 years, asked if I'd checked alkalinity. "Baking soda might fix that," he said. Honestly? I laughed. Baking soda? For pools? Turns out he was dead right.
Why Pool Chemistry Makes Your Head Hurt
Pool maintenance feels like high school chemistry class sometimes, doesn't it? You've got pH, alkalinity, chlorine levels - all these numbers to track. Most folks focus only on chlorine and pH, completely forgetting about total alkalinity (TA). That's where baking soda enters the picture.
The Alkalinity-PH Tango
Think of total alkalinity as your pool's shock absorber. When TA's balanced (80-120 ppm), it keeps pH stable. Low TA? pH starts swinging wildly. High TA? pH gets stubbornly high and scaling happens. That's what baking soda fixes.
| Pool Problem | Caused By Low Alkalinity | Caused By High Alkalinity |
|---|---|---|
| pH Stability | Wild pH swings (pH bounce) | pH stuck at high levels |
| Water Appearance | Cloudy, hazy water | Scale formation on tiles |
| Chlorine Effectiveness | Chlorine burns off quickly | Chlorine becomes sluggish |
See that pH bounce issue? That's exactly why I was struggling last July. My TA had dropped to 50 ppm after heavy rains. Every time I adjusted pH, it'd swing back within hours.
Exactly What Does Baking Soda Do to a Pool?
Here's the straight answer: Baking soda (sodium bicarbonate) primarily increases total alkalinity. Unlike soda ash (sodium carbonate) which spikes pH dramatically, baking soda gently raises TA with minimal pH impact. When you add baking soda to pool water:
- It dissolves into sodium ions and bicarbonate ions
- Bicarbonate acts as a pH buffer against sudden changes
- Prevents corrosive water that damages equipment
- Helps chlorine work more efficiently
Last season I got cocky and dumped a whole box in without pre-dissolving. Big mistake. White powder settled on the floor like snow. Took hours of brushing to dissolve it properly.
Soda Ash vs Baking Soda: What's the Difference?
This trips up lots of new pool owners. Both are white powders, but:
| Property | Baking Soda (Sodium Bicarbonate) | Soda Ash (Sodium Carbonate) |
|---|---|---|
| Main Purpose | Raises alkalinity | Raises pH |
| pH Impact | Small increase (0.1-0.3) | Large increase (0.5-1.0+) |
| Use When | Alkalinity low, pH near normal | Both pH and alkalinity low |
| Cost (per lb) | $0.75-$1.25 | $1.50-$2.50 |
I learned this the hard way when I accidentally grabbed soda ash instead. My pH shot up to 8.4 overnight! Had to add muriatic acid to fix it.
Step-By-Step: How to Add Baking Soda Properly
Don't just dump it in like I did. Here's the right way:
Testing First - Always!
Dip a reliable test strip or use liquid test kit. Alkalinity below 80 ppm? You need baking soda. Above 140? Don't add any.
Calculate Your Dose
For every 10,000 gallons:
- 1.5 lbs baking soda raises TA by 10 ppm
- Example: To raise from 70 to 100 ppm in 15,000 gal pool: (100-70)/10 * (15,000/10,000) * 1.5 = 6.75 lbs
Application Method
- Pre-dissolve in bucket of pool water
- Walk around perimeter while pouring
- Run pump for 4-6 hours
- Retest after 24 hours
My pool's 18,000 gallons. Last time TA was 65 ppm. Added 8 lbs baking soda dissolved in three buckets. Next day? Perfect 100 ppm. Took 45 minutes total.
When Baking Soda Isn't the Answer
Baking soda isn't magic. If your water's green, that's algae - shock it. White crust on tiles? Calcium hardness issue. Brown stains? Probably metals. Know the limits:
- Won't fix: Algae blooms, metal stains, calcium scaling
- Can worsen: High alkalinity (causes scaling), high pH situations
Baking Soda vs Commercial Alkalinity Increasers
Is Arm & Hammer the same as pool store products? Basically yes. Comparison:
| Product Type | Active Ingredient | Cost per lb | Speed of Dissolving |
|---|---|---|---|
| Baking Soda (grocery) | Sodium Bicarbonate (100%) | $0.85 | Medium |
| Pool Store Increaser | Sodium Bicarbonate (98-100%) | $2.50+ | Fast |
| Soda Ash | Sodium Carbonate | $1.75 | Fast |
I buy 13.5 lb Arm & Hammer bags from Costco ($10). Same chemical as Leslie's Alkalinity Up ($35 for 15 lbs). Saves me about $150 per season.
FAQs: Your Baking Soda Questions Answered
Will baking soda clear a cloudy pool?
Only if cloudiness is caused by low alkalinity. Usually not. Cloudy water typically needs shock treatment or clarifier.
Can I use baking soda instead of chlorine?
Absolutely not! Baking soda doesn't disinfect. Your pool would become a bacteria soup within days.
How often should I add baking soda?
Only when tests show low TA. Typically 2-4 times per season unless heavy rain dilutes pool water.
Does baking soda affect saltwater pools differently?
Same function. Saltwater generators prefer TA around 80-100 ppm. Too low causes pH fluctuations.
Can baking soda damage pool liners?
No. It's safe for vinyl, fiberglass, and concrete. Much gentler than many pool chemicals.
What's the shelf life of baking soda for pools?
Keeps indefinitely if stored dry. I keep mine in sealed buckets in the garage.
Why did my pool turn cloudy after adding baking soda?
Either added too much too fast or had existing calcium imbalance. Usually clears in 24 hours with filtration.
Pro Maintenance Schedule
Based on my 10 years of pool ownership mistakes:
| Frequency | Task | Baking Soda Role |
|---|---|---|
| Daily | Skim debris, check pump | Not needed |
| 2-3x Weekly | Test chlorine/pH | Monitor TA weekly |
| Monthly | Full chemical test | Add if TA < 80 ppm |
| Season Opening | Balance all chemicals | Often needed after winter |
After heavy rainstorms, always retest TA. Last month's downpour lowered my TA from 100 to 70 ppm. Added 4 lbs baking soda.
Cost Breakdown: Baking Soda Pool Savings
Let's talk real numbers for a 20,000 gallon pool:
- Commercial alkalinity increaser: $35 for 15 lbs (covers 15 ppm increase)
- Grocery baking soda: $10 for 13.5 lbs (covers 18 ppm increase)
That's 65% cheaper. Over five years, saves about $300 minimum. Plus you avoid the pool store upsell attempts.
My Biggest Baking Soda Mistakes (Learn From Me)
We've all messed up. Here's my hall of shame:
- The Great Cloud-Out of 2020: Dumped 15 lbs at once instead of incremental additions
- pH Neglect: Didn't check pH before adding baking soda when pH was already high
- Bucket Fail: Used a cracked bucket - ended up with baking soda footprints everywhere
Bottom line? Test first. Add gradually. Dissolve properly.
When to Call a Professional
Most baking soda adjustments are DIY-friendly. But call a pro if:
- TA remains low despite repeated additions
- Water stays cloudy over 48 hours after adjustment
- You need to lower alkalinity (requires muriatic acid)
Had to call my pool guy when TA wouldn't rise last fall. Turned out my test kit expired!
Final Reality Check
Baking soda isn't exciting pool tech. It won't automate anything or make your water glow. But properly balanced alkalinity? That's what keeps everything else working smoothly. When pool owners ask me "what does baking soda do to a pool?" I tell them it's the unsung hero of water chemistry. Cheap, safe, and effective when used right.
Now if you'll excuse me - just tested my TA at 85 ppm. Perfect. No baking soda needed today.
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