Quick answer: Keep your nutrient solution between pH 5.5 and 6.5. Test daily, adjust gradually, and buffer weekly for hands-off stability.
Why pH swings (and why our water makes it trickier)
Australian tap water often rolls out of the faucet at pH 7.2–8.4 thanks to hardy bicarbonates added for pipe protection. Tip that alkaline water into a nutrient tank rich in salts, and the chemistry can seesaw—locking out iron, calcium and magnesium right when your lettuce or basil needs them most. Left unchecked, you’ll spot yellowing between the veins, twisted new growth and stalled yields.
If your plants show hunger signs even with perfect pH, you might be under- or over-feeding. Mastering EC Balance: A Beginner’s Guide for Hydroponic Growers in Australia explains how to match EC to each crop so pH adjustments actually deliver results.
The must-have toolkit
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What it does |
Grab it |
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One-dip read-out of pH, EC & temp |
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Pocket checker for daily spot tests |
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Gentle nudge down using food-grade citric acid |
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Boost pH up with potassium carbonate |
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Old-school colour kit + mini Up/Down bottles for emergencies |
Tip: Keep all bottles snug in a cool cupboard—heat degrades reagents fast in an Aussie shed.
The 3-step “daily driver” routine
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Test & log (30 sec)
Dip your Combo Meter or Pen, wait for the reading to stabilise, then jot pH/EC/Temp in a notebook or phone app. Trends matter more than one-offs. -
Adjust in micro-doses (60 sec)
Start small: 0.5 ml of pH Down per 10 L often shifts the reading by 0.2 pH. Stir for two full minutes and retest. Overshoot? Bring it back with a splash of pH Up—never with straight tap water. -
Stabilise & buffer (weekly)
• Top up with fresh nutrient solution rather than plain water.
• Rinse probes in distilled water, then recalibrate to pH 7.0 & 4.0 standards.
• Empty and scrub reservoirs every 7-10 days to flush acid-forming biofilm.
pH drift cheat-sheet
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Symptom |
Likely cause |
Quick fix |
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pH rises 0.3+ each day |
Hard water, rapid veg uptake |
Pre-filter with a small RO unit or dose extra pH Down daily |
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pH crashes overnight |
Bacterial bloom, over-feeding carbs |
Increase aeration, add beneficial microbes, halve organic additives |
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Iron-deficiency yellowing at pH > 7.0 |
Nutrient lock-out |
Bring pH back to 5.8 and foliar-spray a trace mix |
FAQs
How often should I adjust pH?
Newbie rule: check daily for the first fortnight. Once readings hold steady (< 0.1 drift), you can test every second day.
Do I need reverse-osmosis water?
Not always. If tap water EC is < 0.3 mS cm-¹ and you’re happy dosing a touch more pH Down, you’re sweet.
Can I use household vinegar or baking soda?
Skip them. They lack buffers, swing wildly, and leave residues that clog drippers.
Ready to lock it in?
Grab everything in one go via our pH Control collection and score free shipping over $250. Your plants—and your future self—will thank you.
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