· By Chris Gaffney
Why Water Quality Matters More Than Most Growers Realize đź’§
What’s in Your Water Shapes Everything
Before nutrients.
Before training.
Before even planting.
Water quality is one of the most important — and most ignored — factors in a successful grow.
No matter how you grow (soil, coco, hydro, living soil), every input starts with water. If the water going into your plants is poor, everything downstream becomes harder.
That’s why, before receiving clones and starting a grow, it’s critical to understand what kind of water you’ll be using throughout the entire life cycle.
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Water Is the Delivery System 🌱
Water does more than hydrate a plant.
It:
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Carries nutrients
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Feeds microbial life
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Affects pH and EC
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Determines nutrient availability
If water quality is inconsistent or contaminated, plants struggle to uptake what they need — even if everything else is dialed.
This becomes especially important when starting with cultivation-ready clones, since clones respond quickly and clearly to water inputs.
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Understanding PPM (Parts Per Million) đź§Ş
PPM (parts per million) measures how much “stuff” is dissolved in your water.
This includes:
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Minerals
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Salts
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Treatment chemicals
General Water Quality Guidelines
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0–50 PPM → Very clean (RO or distilled)
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50–150 PPM → Good tap water
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150–300 PPM → Usable, but monitor closely
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300–500 PPM → Poor quality for plants
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500+ PPM → Not considered safe for drinking
If water isn’t great for people, it’s usually not great for plants either.
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Understanding EC (Electrical Conductivity) ⚡
Another Way to Measure What’s in Your Water
EC (electrical conductivity) is simply another way to measure how many salts or conductive materials are dissolved in water.
Instead of counting particles like PPM, EC measures:
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How easily electricity moves through the water
The more dissolved salts present, the higher the EC reading.
In practical terms:
Higher EC = more dissolved material in the water
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EC vs PPM — Which Is Better?
Neither is better — they’re just different units of measurement.
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Some feeding charts use PPM
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Others use EC
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Both describe the same thing: dissolved content
As long as you know what scale you’re using, both are perfectly valid.
This is why many growers reference an EC to PPM conversion chart (link) to translate between the two depending on the feeding schedule or nutrient line they’re using.
The key is consistency — not switching back and forth without understanding the numbers.
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Why High PPM / EC Water Causes Problems ⚠️
Water with high dissolved content can:
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Compete with nutrient uptake
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Throw off feeding charts
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Build salts in the root zone
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Create inconsistent EC readings
In biological systems, high EC water can also:
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Suppress microbial activity
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Reduce nutrient cycling
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Damage beneficial organisms
Knowing your starting EC or PPM lets you adjust intentionally, not reactively.
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Chlorine, Chloramine, and Microbial Life đź¦
Most municipal water is treated to be safe for humans — not plants.
Common treatments include:
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Chlorine
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Chloramine
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Other disinfectants
These chemicals:
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Kill harmful bacteria (good for drinking)
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Also kill beneficial microbes (bad for soil biology)
If you’re running:
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Soil
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Living soil
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Coco with microbes
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Compost teas or ferments
…this matters a lot.
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Easy Ways to Dechlorinate Water đźšż
One simple method:
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Fill a 5-gallon bucket
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Add an air stone
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Aerate for 24 hours
This allows chlorine (not chloramine) to off-gas naturally.
For chloramine-heavy water, filtration is usually required.
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Tap Water by Region (General Patterns) 🗺️
Water quality varies widely by location.
Typically lower PPM regions:
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Pacific Northwest
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Parts of the Northeast
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Areas with mountain-fed reservoirs
Typically higher PPM regions:
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Southwest
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Desert states
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Agricultural regions
Major cities often have:
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Higher PPM
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More treatment chemicals
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Older infrastructure
This doesn’t mean you can’t grow with city water — it just means testing and filtration become more important.
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Filtration Options (Simple Overview) đź§
Growers commonly use:
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Carbon filters (chlorine removal)
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RO systems (full reset)
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Inline garden filters (basic improvement)
The right choice depends on:
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Starting PPM or EC
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Chlorine vs chloramine
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Growing style
Testing always comes first.
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Tools That Make This Easy 📏
A simple PPM/EC meter removes all guesswork.
Meters like those from Bluelab allow growers to:
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Measure PPM accurately
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Track EC consistently
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Understand what’s actually in their water
Once you know your baseline, everything else becomes more predictable.
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Why This Matters Before You Start 🌿
Before plants ever arrive:
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Environment should be dialed
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Water quality should be known
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Filtration decisions should be made
Starting with uniform genetics from clones makes water-related issues easier to identify — plants respond consistently, making troubleshooting clearer.
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Final Takeaway ✨
đź’§ Water carries everything
đź§Ş PPM and EC tell the truth
🦠Treatment chemicals affect microbes
📏 Testing removes guesswork
If there’s one thing every grower should understand early, it’s their water.
Everything flows from there.
Grown with care. Always. 🌿
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Learn and Grow With Us 🌱
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Explore our grow guides (link)
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Talk to our grow assistant (link)