This article is intended for informational purposes only. Always follow manufacturer instructions and consult a pool professional before making adjustments to your pool’s chemistry. Improper chemical handling can cause damage or injury.
Chemistry probes are not designed to withstand freezing conditions. Probes must be removed and stored according to winterization procedures. Freeze damage will result in permanent probe failure and is not covered under warranty.
Maintaining proper water chemistry in a pool isn’t just about clear water—it’s about safety, comfort, and protecting your equipment. Two of the most important (and misunderstood) chemical levels are pH and ORP. When either one is off, it can throw your entire system out of balance. With The Attendant, you have the tools to monitor, adjust, and fix these issues directly from the touchscreen or app.
Here’s how to troubleshoot and correct the most common pH and ORP problems using The Attendant.
Understanding pH and ORP
- pH measures how acidic or basic your water is. Ideal range: 7.4–7.6
- Low pH = acidic water → corrosive to surfaces and equipment
- High pH = basic water → scale formation and poor sanitizer performance
- ORP (Oxidation Reduction Potential) measures the water’s ability to oxidize contaminants—essentially, the effectiveness of your sanitizer (usually chlorine). Ideal range: 650–750 mV
These two levels are closely related: if pH is too high or too low, it can directly affect your ORP reading—even if your chlorine levels seem fine.
Common pH & ORP Problems (and How to Fix Them)
1. High pH, Low ORP
Symptoms:
- Cloudy water
- Weak sanitizer performance
- Visible algae
- Strong chlorine smell (chloramines)
Causes:
- Inadequate acid dosing
- High alkalinity
- Acid mixture too weak
- Incorrect pH setpoint or slow dosing frequency
Fixes Using The Attendant:
- Check Chemistry Tables
Go to Chemistry > Acid > Dosing Table. Ensure the system is set to add acid above your setpoint and increase dose volume as pH rises. - Strengthen Acid Mixture
If you’re feeding a diluted acid solution, increase the concentration slightly (consult your chemical supplier first). Typical ratios for residential pools are 4:1 or 3:1 water to acid. - Dosing Amount
Go to Chemistry > Acid > Dosing Table > Dosing Amount. Increase dosing (e.g., from 10 oz to 20 oz) to improve correction speed. - Adjust Mixing Time
Decrease the post-dose mixing delay. While mixing time helps stabilize readings, too long of a delay can cause sluggish corrections. - Manual Acid Dose
There’s no dedicated “Manual Dose” button on The Attendant, but you can manually add acid to correct water quickly, then allow The Attendant to maintain balance. This can be faster than relying solely on automation during catch-up situations.
2. Low pH, High ORP
Symptoms:
- Irritated eyes or skin
- Corroded heaters or stainless hardware
- Acidic odor
- High ORP despite normal chlorine
Causes:
- Overactive acid feed
- pH setpoint too low
- Strong acid mixture
- Dosing too frequently
Fixes Using The Attendant:
- Raise the pH Setpoint
Go to Chemistry Settings and increase the pH target to reduce acid dosing frequency. - Reduce Dose Volume
Adjust the pH dose size in the chemistry table to smooth out dosing and prevent overshooting. - Dilute Your Acid Mix
Try a 4:1 or 3:1 water-to-acid ratio if you’re currently using full-strength muriatic acid. A weaker mix provides more controlled corrections. - Check Flow Switch and Probe Location
Make sure probes are in the flow cell and reading fully circulated water—not stagnant or untreated water.
3. ORP Not Matching Chlorine Levels
Symptoms:
- ORP is low, but free chlorine tests show 2–4 ppm
- Water appears dull or smells bad
- ORP probe shows inconsistent readings
Causes:
- High cyanuric acid (CYA)
- Dirty or aging ORP sensor
- Poor flow across the probe
- Lack of calibration
- Old Chlorine test solution
Fixes Using The Attendant:
- Check Probe Age
ORP probes typically last 12–24 months. If it’s over 18 months old, consider replacement. - Calibrate the ORP Sensor
Use a standard ORP calibration solution and follow the on-screen wizard. - Clean the Probe and Flow Cell
Remove and inspect the flow cell. Ensure good water flow and no bubbles, obstructions, or buildup. Clean the ORP sensor. - Compensate for CYA
High CYA reduces ORP responsiveness. If CYA is over 50 ppm, increase your ORP setpoint slightly (e.g., to 750–770 mV) or reduce CYA levels.
4. The Attendant’s pH Reading Doesn’t Match Manual Test
Symptoms:
- The Attendant shows pH of 8.1, but your test kit reads 7.6
- Dosing appears ineffective or inconsistent
- pH doesn’t respond to adjustments as expected
Causes:
- pH probe needs calibration or cleaning
- Probe is in stagnant or poorly mixed water
- Acid isn’t dispersing before the next reading
- High or unstable alkalinity
Fixes Using The Attendant:
- Inspect Sensor Placement and Flow
Make sure the pH probe is installed where water is flowing—ideally in a flow cell or well-circulated return-side plumbing. Avoid dead legs or bypassed lines. - Calibrate the pH Probe
Go to Chemistry > Calibrate pH and use a fresh buffer solution. Rinse with distilled water before and after. Calibration should be done every 6 months—or more frequently if readings drift. - Clean the Probe
Remove the probe and soak in pH probe cleaning solution to remove buildup. Rinse thoroughly before reinstalling. - Increase the Mixing Delay
Go to Settings > Chemistry > pH Settings and extend the Mixing Delay. This allows time for acid to mix before a new reading is taken. Without this delay, the system may report artificially high pH. - Check Alkalinity Manually
The Attendant doesn’t measure alkalinity, but it significantly affects pH stability. If TA is over 120 ppm, pH may bounce back after correction. Lower TA before attempting to fine-tune pH.
Bonus Tips Using The Attendant
- Enable Alerts
Set custom thresholds for pH and ORP to receive push notifications if levels go out of range. - Remote Monitoring
Check and adjust chemistry in real time using The Attendant app—perfect for service pros and remote homeowners. - Graph Trends
Use Chemistry Graphs to track long-term trends and identify problem patterns after storms, high bather loads, or equipment issues. - Sync with Salt Systems
If you’re using a salt cell, The Attendant can monitor ORP and adjust cell output based on actual sanitation demand—not just a timer.
Final Thoughts
The Attendant gives you unparalleled control over your pool’s water chemistry—but automation is only as good as its setup. By calibrating your probes, maintaining proper flow, adjusting your dosing tables, and keeping an eye on long-term trends, you can quickly correct most pH and ORP issues right from the app or touchscreen.