Growing pak choi in a hydro tower: from seed to harvest
Pak choi grows fast and forms lots of leaf mass. I show you how I germinate it, raise it in the seedling station and harvest it in the tower, with all values from my book.
🎯
pH 5.5 to 6.5
I set it to 5.8
⚡
EC 0.5 to 1.8
rises in four stages with the plant
🌡️
20 to 25 °C
for germination, pak choi is a dark germinator
💡
175 to 225 PPFD
light indoors, 14 to 16 hours
Why pak choi does so well in the tower
Pak choi is a leafy plant. It stays in growth all its life, and you harvest the leaves. That’s why my liquid nutrient is enough for it from sowing to harvest, switching to bloom nutrient isn’t needed. It grows fast, gets nice and wide and brings a really big harvest from every opening.
Without soil every plant gets exactly the nutrients it needs right now, and the roots always have water and air. You don’t water, you measure. The photos on this page all come from my own growing.
My growing plan
Pak choi step by step
Tap a phase to see the matching values. Below, calculate from your sowing date when each step is due.
Germination in the seedling box
One seed per foam cube. Pak choi is a dark germinator: put the seed in the slit, don’t press it in, lid on so it lies in the dark, and place it somewhere warm. Water only, no nutrient yet.
When the seedling stands stable and shows first roots, it goes into the 5 cm net pot in the seedling station. Light on, lid off, start with a little nutrient.
The days are guidelines from my growing. Light, temperature and variety shift them a little. What matters is how your plant looks.
Pak choi profile
What
Value
Plant group
leafy plant, you harvest the leaves
Germination
dark germinator, 20 to 25 °C, usually 4 to 7 days
Seeds per cube
one
pH value
5.5 to 6.5, my target 5.8
EC value (mS/cm)
seedlings 0.5, young plant 0.9, growth 1.4, harvest 1.8
Pump indoors
5 minutes on, 30 minutes off
Pump outdoors in heat
15 minutes on, 15 minutes off
Light
seedlings 100 to 150 PPFD, growth 175 to 225 PPFD, 14 to 16 hours
Harvest
outer leaves continuously or the whole rosette before it bolts
The seed packet comes first
Germination time and temperature vary by variety. If your packet says something different from my table, go by the packet.
1Germinating in the seedling box
day 0 to 7 · water only
I start pak choi in foam cubes. Before first use I rinse the cubes thoroughly with hot water and let them cool. Then I fill the seedling box about a third with water, so the cube stays evenly moist without the seed spot being permanently under water.
Exactly one seed goes into each cube, because pak choi becomes a big single plant. Pak choi is a dark germinator. So put the seed in the slit of the moist cube, spray briefly and put the lid on the box. You don’t need to press it in, the lid makes it dark. 20 to 25 °C is ideal. I check every day: the cube mustn’t dry out, but mustn’t be dripping wet either.
After four to seven days the seedlings are usually up. Then the lid comes off, the lamp goes on, and I air regularly. No feeding in the germination phase yet.
Temperature
20 to 25 °C
Germination type
Dark germinator
Duration
usually 4 to 7 days
Nutrient
none yet
Pak choi seeds: one seed per cube is enough.The seeds go into the moist cubes, then lid on.
Joi Choi pak choi seeds, mild and bolt-resistant. I use one seed per cube.
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Plant labels so variety and sowing date are clear from day one.
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Waterproof pen, the writing stays readable even when damp.
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Fine tweezers if you want to place the small seeds precisely.
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Label printer, practical with many varieties and several sowing dates.
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2Seedlings in the station
about day 7 to 21 · EC 0.5, then 0.9
When the seedling stands stable and the first light roots are visible, I put the cube into a 5 cm net pot and place it in the seedling station. At first the cube can touch about 0.5 centimetres of water. Once several roots reach safely into the nutrient solution, I lower the water level so 0.5 to 1 centimetre of air remains between pot and water.
Now feeding begins with my liquid nutrient. I increase in small steps and always check with the meter, first EC, then pH. In the station I change the nutrient solution completely once a week.
Plant stage
Frankie’s liquid nutrient
EC target (mS/cm)
Germination
0 ml per litre
water only
after germination
0.5 ml per litre
about 0.5
first true leaves
1 ml per litre
about 0.9
strong young plant in the tower
2 ml per litre
about 1.4
big plant before harvest
up to 3 ml per litre
up to 1.8
The millilitres apply to my nutrient and are guidelines. If your tap water already has a high EC, you need less. What matters is the EC of the finished solution.
EC
0.5 to 0.9
pH
5.5 to 6.5, target 5.8
Light
100 to 150 PPFD
Water change
weekly
In the seedling station the plants keep growing until the roots are safely in the water.Strong, light roots outside the pot: now the plant is ready for the tower.
Bluelab OnePen: pH, EC and temperature in one device, if you measure regularly.
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Permanent monitor for pH, EC and temperature. Stays in the reservoir, you see deviations immediately.
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Calibration solution so your pH measurement stays reliable.
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Thermometer with probe for the nutrient solution temperature.
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Thermometer and hygrometer for temperature and humidity at the seedling spot.
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Clip fan for gentle air movement. It makes the stems sturdier, never point it directly at the plants.
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Measuring cylinder so nutrient and pH adjuster are measured exactly.
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3Growth in the hydro tower
from about day 21 · EC 1.4
The young plant only goes into the tower once it has several true leaves, stable growth and roots outside the cube. After planting I check immediately whether water reaches every occupied opening. I now set the EC to about 1.4, the pH to 5.8.
Pak choi grows fast and gets wide. I leave enough space between big plants so the leaves don’t touch or shade each other permanently. I close free openings with cover caps.
Young and big plants in the same tower
If young and big plants stand together, set them all to an EC of about 1.1 to 1.2. The young ones cope well with that. Only the reverse is bad, when big plants get a solution meant for young plants.
Pump timing
Indoors my pump runs for 5 minutes and then pauses for 30 minutes. That’s enough, the roots stay moist. Outdoors in blazing sun I increase to 15 minutes on and 15 minutes off. If the leaves droop, the pause is too long. The air pump doesn’t go on the timer, it runs constantly and brings oxygen to the roots, especially when the water gets warm.
EC
about 1.4
pH
Target 5.8
Pump indoors
5 on, 30 off
Pump in heat
15 on, 15 off
Pak choi gets wide, give it enough space in the tower.
Digital timer with cycle function. I set 5 minutes on and 30 minutes off.
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Submersible pump for the tower. Make sure the lift height suits your tower.
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Air pump for beginners. Brings oxygen to the roots.
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The big air pump I use myself, with hoses and air stones for many reservoirs.
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Air stones that spread the bubbles finely in the water.
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pH down and pH up for beginners. Add a small amount, stir, measure again.
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Phosphoric acid as a concentrated pH down. Wear safety glasses and gloves, always add acid to water.
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From my shop
Everything for your soil-free start
HydroFlex Tower for indoors and outdoors, seedling box, seedling station, support rings and my own nutrient. After you buy, I’ll help you on WhatsApp.
Big plants tolerate an EC up to about 1.8. For a continuous harvest I cut single big outer leaves as low as possible with clean scissors. The heart in the centre stays, then new leaves grow back.
For the complete harvest I cut the whole rosette just above the cube. I harvest in time, before a flower stalk shoots up in the centre, because then the leaves get tougher and more bitter. I briefly rinse the leaves before eating.
use clean, sharp scissors
cut outer leaves as low as possible
leave the heart for regrowth
rinse leaves before eating
Ready-to-harvest pak choi from my tower, with strong leaves and dense roots.
Light and growing indoors
Indoors pak choi grows compact if it gets enough light and the air between the leaves doesn’t stand still. Seedlings need 100 to 150 PPFD, in growth pak choi wants about 175 to 225 PPFD. I measure directly at the height of the top leaves, phone apps only show approximate values.
On the tower my lamps hang at the side, 20 to 30 cm from the plants, because from above the light hardly reaches the lower levels. With a strong lamp 14 hours are enough, with a weaker one I leave it on for 16 hours, but never longer. A small fan moves the leaves gently. It doesn’t replace airing the room.
Seedlings
100 to 150 PPFD
Growth
175 to 225 PPFD
Light duration
14 to 16 hrs
Lamp
at the side, 20 to 30 cm
Indoors I check light, air movement, pH and EC right at the tower.
Seedling shelf with lamps, space-saving for several crops.
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PPFD meter. Measures the light where it counts: at the leaves.
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Mars Hydro VG40 for smaller areas and single shelves.
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Linear lamps, suitable for shelves and several seedling boxes side by side.
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Mars Hydro VG80 for bigger areas and stronger light.
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Brown leaf edges on pak choi
Brown, dry leaf edges are called tipburn. They mainly occur in lettuce, often in pak choi too. Almost always nothing is missing in the water. The calcium is there, it just doesn’t reach the edges of the young leaves. Calcium only travels with the water flow, and the leaves create that themselves by evaporating. The young heart leaves evaporate little and are the first to get too little.
In heat the outer leaves evaporate so much that hardly anything is left for the centre. Very dry air dries out the edges, still air slows evaporation. That’s why gentle air movement is so important. But if a fan blows directly on the plants or the lamp hangs too close, the edges dry out too. Too high an EC can also burn the tips. So check EC, pH and roots first before changing anything. Brown edges don’t turn green again, but the new leaves grow back healthy.
Your growing card for pak choi
Anzuchtkarte · frankiesgarten.dePak ChoiVom Samen bis zur Ernte im Hydro Tower
Meine Notizen
Sorte:
Hersteller:
KeimtypDunkelkeimer
Keimen bei20 bis 25 °C
Keimdauer4 bis 7 Tage
Samen je Würfel1
pH-Ziel5,8
Wasser18 bis 22 °C
Licht14 bis 16 Std.
Pumpe drinnen5 an / 30 aus
Dünger, EC und pH
Phase
EC (mS/cm)
Frankies Dünger
pH
Anzucht (erste Blätter)
0,5
0,5 ml pro Liter
5,5 bis 6,5
Jungpflanze
0,9
1 ml pro Liter
5,5 bis 6,5
Wachstum im Tower
1,4
2 ml pro Liter
5,5 bis 6,5
Ernte
bis 1,8
bis 3 ml pro Liter
5,5 bis 6,5
Zeitplan und Beobachtungen
Ausgesät am:
Gekeimt nach:Tagen
Erste echte Blätter nach:Tagen
In die Anzuchtstation nach:Tagen
In den Tower nach:Tagen
Erste Ernte nach:Tagen
Beginnt zu schießen nach:Tagen
Pflege
Samen in den Schlitz legen, nicht eindrücken.
Deckel auf die Anzuchtbox, dann liegt der Samen dunkel.
Erst EC messen, dann pH.
Nachfüllen mit fertiger Nährlösung.
Bei Hitze schießt Pak Choi schneller.
Blätter von außen ernten oder die ganze Rosette.
⚠️ Darauf achten: mögliche Schädlinge
Erdflöhe: viele kleine Löcher im Blatt, vor allem draußen. Feucht halten, Netz drüber.
Kohlweißling: grüne Raupen fressen große Löcher. Blätter absuchen, Netz drüber.
Blattläuse: an Blattunterseiten und im Herz. Mit Wasser abbrausen.
Schießen: bei Hitze und langen Tagen bildet er Blüten. Rechtzeitig ernten.
Mein Tipp für draußen: Ein feines Insektenschutznetz über den Tower stülpen.
Here you’ll find answers for getting started and for typical questions in the running tower. Work step by step: first observe and measure, then only change the value that’s really off.
Is pak choi suitable for hydroponics beginners?
Yes. Pak choi grows fast, forms lots of leaf mass and suits the hydro tower well. A germination temperature of 20 to 25 °C, even moisture and enough light after germination are important. With staggered sowing you have several stages in the system at the same time.
How do I sow pak choi in a foam cube?
I use one seed per foam cube. Pak choi is a dark germinator, so I put the seed in the slit of the moist cube and put the lid on the seedling box. I don’t need to press it in, the lid makes it dark. In the germination phase there’s only water. As soon as the seedling is visible, it gets light and fresh air.
Why isn’t my pak choi germinating?
Common causes are a dried out or permanently too wet cube, too cool a temperature or old seed. Pak choi germinates best at 20 to 25 °C and needs darkness, you don’t need to press the seed in, the lid on the seedling box provides darkness. Usually the seedling shows after four to seven days. You’ll find the process in the section Germination.
What temperature does pak choi need to germinate?
I plan for 20 to 25 °C, then pak choi usually germinates after four to seven days. Cooler conditions slow the start. As soon as the seedling is there, the box comes away from the warmth, the lid comes off and the light goes on.
How moist does the foam cube have to be?
Evenly moist, but not dripping wet. I fill the seedling box about a third with water and put the lid on. The cube mustn’t dry out, but the seed spot shouldn’t stand permanently under water. I check daily.
How many pak choi seeds go into one cube?
Exactly one. Pak choi forms a big single plant, several seeds would take each other’s space. The seed isn’t pressed in, the lid on the seedling box makes it dark.
When does pak choi go into the seedling station?
When the seedling stands stable and shows the first light roots. Then the cube goes into the 5 cm net pot and into the seedling station. Very fresh seedlings dry out faster when transplanted. Afterwards check whether the roots reach the water.
How high is the water level in the seedling box and seedling station?
In the seedling box the water stands at about a third of the height. In the seedling station the cube touches about 0.5 cm of water at first. Once several roots grow safely into the nutrient solution, I lower the level so 0.5 to 1 cm of air gap remains.
How do I stagger sowing so I harvest pak choi regularly?
Pak choi gets much bigger than loose-leaf lettuce and needs space. Depending on free openings, start a small new group every seven to fourteen days. Note the sowing date and only add as many young plants as the tower can take with enough spacing.
When and how much nutrient does pak choi get?
During germination there’s only water. After germination I start with 0.5 ml of my liquid nutrient per litre, with the first true leaves 1 ml, in growth 2 ml and for big plants up to 3 ml per litre. The meter decides: EC 0.5 for seedlings, 0.9 as a young plant, 1.4 in growth and up to 1.8 for big plants.
What pH value does pak choi need?
Pak choi tolerates pH 5.5 to 6.5, I set it to 5.8. That’s where the plant can reach most nutrients well. Always finish setting the EC first, then measure and correct the pH, because the nutrient changes the pH.
What EC value does pak choi need?
It rises with the plant: about 0.5 for seedlings, 0.9 as a young plant, 1.4 in growth and 1.8 before harvest. Always measure your starting water first and then the finished nutrient solution. The millilitre figure doesn’t replace the meter.
Does pak choi need grow light in the flat?
For reliable growing indoors, especially in autumn and winter, yes. A bright windowsill often doesn’t supply light evenly enough for compact plants. You’ll find the right values in the section Light and growing indoors.
What does PPFD mean for grow lights?
PPFD is the amount of light usable for photosynthesis that reaches the plant. It’s measured at leaf height, wattage and distance alone don’t tell you reliably. Seedlings need 100 to 150 PPFD, pak choi in growth about 175 to 225 PPFD.
How long does the grow light shine and how far away does it hang?
With a strong lamp 14 hours are enough, with a weaker one 16 hours, but never longer. On the tower the lamp hangs at the side, 20 to 30 cm from the plants. Check the exact distance with a PPFD measurement at leaf height.
Why do my pak choi plants have long stems and thin leaves?
That’s usually too little light, often together with too much warmth. The plant stretches towards the light source. Check the PPFD value at leaf height and adjust distance, power or duration step by step.
Why does pak choi need a fan indoors?
A small fan moves the air around the leaves, so damp spots dry faster and more calcium reaches the young leaves. The leaves should only move gently, it never blows directly on the plants. It doesn’t replace airing the room.
How do I prevent high humidity and mildew?
Air regularly, ensure gentle air movement and give the plants space. Permanently wet leaves lying against each other encourage fungal diseases. If it gets too dense, harvest outer leaves earlier or take out single plants.
Why is pak choi turning bitter or bolting?
Heat, long bright days, drought stress and staying in the tower too long make pak choi flower, the leaves then get more bitter. Harvest in time and keep the nutrient solution as cool as possible. A strong flower stalk in the centre shows the end of the harvest time, that’s completely normal.
What do I check first if the pak choi suddenly looks bad?
Don’t add more nutrient on suspicion. First check water level, pump and water flow, then water temperature, EC and pH. After that look at roots, leaf undersides, light and air movement and only change one value specifically.
Why is my pak choi getting brown leaf edges?
That’s usually tipburn. The calcium is in the water but doesn’t reach the edges of the young leaves, because it only travels with the water flow. Causes are heat, very dry or still air, a fan directly on the plants, a lamp that’s too close or too high an EC. Check EC, pH and roots first, brown edges don’t turn green again, but the new leaves grow back healthy.
Why are my pak choi leaves turning pale or yellow?
First look whether only old outer leaves or also new heart leaves are affected. Then check water flow, roots, water temperature, pH, EC and light. A wrong pH blocks uptake even though there’s enough nutrient in the water. Don’t change several things at once.
Do I have to plant every opening in the hydro tower?
No. Pak choi gets wide and needs light and air. If you leave single spots free, the leaves touch less. I close free openings with cover caps so no light falls into the water and algae have little chance.
Can I mix pak choi, parsley and smaller young plants?
Yes, if they tolerate similar values and don’t shade each other. Parsley grows slimmer, pak choi wider. You can temporarily put smaller pre-grown plants into free spots and move them later.
Can I plant young and older pak choi plants together?
Yes, if the young plants already have true leaves and visible roots, about five to nine centimetres tall. If young and big plants stand together, I set them all to an EC of about 1.1 to 1.2. The young ones cope well with that, only the reverse would be bad.
How do I harvest pak choi correctly?
You can cut single outer leaves low with clean scissors and leave the heart, then the plant keeps growing. Or you cut the whole rosette just above the cube. Harvest before a flower stalk shoots up.
Can pak choi grow outdoors in the hydro tower?
Yes, if the location is bright and the tower stands securely. In sun and wind check the water level more often, outdoors in heat the pump runs 15 minutes on and 15 off. Summer heat and long days encourage bolting, spring and autumn are ideal.
Why does my pak choi have small holes in the leaves?
Possible culprits are flea beetles, young caterpillars, slugs or rubbing. You can’t reliably identify the cause from the hole pattern alone. Check top and undersides in the morning and evening for animals, eggs, droppings or slime trails and only then choose a measure.
How do I protect pak choi from cabbage whites and caterpillars?
A fine-mesh crop net, fitted early and sealed all round before butterflies lay eggs. Still check the leaf undersides for yellow eggs and young caterpillars and pick them off. The net keeps new butterflies away but doesn’t remove animals already underneath.
What do I do about aphids on pak choi?
Separate a heavily infested plant and carefully rinse small colonies off with water. Repeat the check over the next few days. If a product becomes necessary, only use one approved for edible crops and follow application and waiting time exactly.
What does the EC value mean?
The EC value shows how well the water conducts electricity. Dissolved salts from tap water and nutrient raise it, so it shows how strong the nutrient solution is overall. It doesn’t say which individual nutrient is in it. The usual unit is mS/cm.
What does the pH value mean?
The pH value shows whether a solution is acidic, neutral or alkaline. It decides how well the roots take up the individual nutrients. For pak choi I set 5.8, only after the EC is finished.
Which meters do I need as a beginner?
At least a pH and an EC meter or a good combination meter. A water thermometer makes sense, indoors a PPFD meter helps for the light. Rinse the probes after measuring and store them as the manufacturer says.
Why do pH and EC meters need calibrating?
Meters drift over time, then the display shows a precise number that’s still wrong. Calibrate regularly with fresh calibration solution as instructed and rinse the probe before and after each solution. If the values suddenly jump, check cleaning and calibration first.
Can I use normal tap water for hydroponics?
Yes, if you measure it. Soft water is below EC 0.3, medium 0.3 to 0.5, hard above. Soft water leaves more room for nutrient, with hard water the leeway is smaller.
What does a high EC of my tap water mean in practice?
If your pak choi should be at EC 1.4 in the tower and your tap water already has 0.8, only about 0.6 remains for nutrient. With young plants at 0.9 the leeway is even smaller. Then you can’t simply add the full amount by the millilitre figure.
What do I do with very hard tap water?
Mix it half and half with clean rain or RO water, that roughly halves the hardness. Then measure again. I don’t use pure rain or RO water alone, it barely buffers and the pH swings more.
Why does the EC rise in a running hydro tower?
Usually because the plants take up more water than nutrient salts and the water in the reservoir gets less. First top up water to the normal level, mix well and measure again. If the EC stays clearly too high, pump out the solution and mix fresh.
How often do I change the nutrient solution?
In the seedling station completely once a week. In the running tower I top up with ready-mixed nutrient solution, measure and balance. If the water smells odd, the roots look bad or the EC rises for no reason, I mix fresh. The pump must never run dry.
Why shouldn’t I just top up the nutrient solution?
Topping up is exactly right in the running tower, but always with measuring. I top up with ready-mixed nutrient solution and then check EC and pH: if the EC is too low, a little nutrient goes in, if it’s too high, plain water. If the EC keeps rising or deficiency shows, I mix completely fresh.
What do I set first: EC or pH?
Always EC first. The nutrient also changes the pH, if you set the pH first you’d have to correct it again afterwards. So: water, nutrient, check EC, then carefully bring the pH to 5.8 and measure again.
How do I mix fresh nutrient solution with a 10 litre watering can?
First water into the can, then the calculated amount of my liquid nutrient, mix well. With my soft water I start a little stronger and keep letting water run in until the EC is right. Only then do I set the pH to 5.8. I hold the meter in the mixed solution, not in the stream of water.
How do I measure the EC correctly when mixing?
Rinse the probe, first measure the plain starting water, then mix in the nutrient. Measure in the well-mixed solution and wait until the display is steady. Too low: add a little nutrient, too high: dilute with water, then measure again.
What do I do if I’ve added too much nutrient?
Dilute. Gradually add clean water, mix and measure until the target value fits. If the can isn’t big enough, split the mix into two containers. pH down doesn’t lower the EC, check the pH right at the end.
How do I correct the pH without overdosing?
The EC must already be right. Add only a very small amount of pH down, mix and measure again, only then follows the next small addition. If you’ve added clearly too much, dilute with water or mix fresh.
Why does my pH keep rising after lowering it?
Usually the tap water buffers, mainly through bicarbonate, which neutralises part of the acid. Carbon dioxide gassing out and nutrient uptake by the roots also make the pH rise. How strongly your water buffers is shown by the carbonate hardness in your supplier’s water analysis.
Can I use citric acid to lower the pH?
It lowers the pH in the short term, but I don’t recommend it for a running tower. Microorganisms break it down, the pH often rises again after hours, and you bring organic matter into the water. I use a mineral pH down, phosphoric acid in my case.
How do I use phosphoric acid to lower the pH?
With my phosphoric acid and my soft water I start with two drops for 10 litres of finished nutrient solution, mix and measure. If the pH is still above 5.8, at most one more drop goes in. That doesn’t automatically apply to every product. Wear safety glasses and gloves and always add acid to water, never water to acid.
Is phosphoric acid in the nutrient solution harmful to pak choi?
Not in small, correct amounts. In the diluted solution it’s mostly present as phosphate, which the plant uses as a nutrient. Only overdosing and too low a pH are problematic, so measure after every addition.
Does pak choi from the hydro tower actually taste good?
Yes. Hydroponics only describes how the roots are supplied, it doesn’t take flavour away from the plant. What matters is variety, light, temperature, nutrients and harvest time. I harvest in time and eat the leaves as fresh as possible.
Does hydroponic pak choi just taste of water?
No. Mild varieties taste mild in soil too. Little light and very fast growth can make the leaf softer and milder, but that’s due to the conditions and not hydroponics.
Is pak choi from the hydro tower crunchy?
Yes, if variety, light, temperature and water supply are right. Heat, little light, over-mature plants or long storage make the leaves softer. Harvest fresh, rinse briefly in cold water and store cool.
Does hydroponic pak choi contain vitamins?
Yes. In the tower too, pak choi forms vitamins and other compounds itself through photosynthesis and metabolism. Exactly how much depends on variety, light, temperature, nutrients, age and harvest time. Blanket comparisons with pak choi from soil can’t be made without lab analysis.
Which vitamins and minerals does pak choi contain?
Pak choi contains vitamin C, vitamin K, folate and carotenoids as a precursor of vitamin A, plus minerals like potassium and calcium, among other things. The amounts vary depending on variety, growing and storage. For my own growing I don’t state exact contents without lab analysis.
Where does pak choi get its nutrients without soil?
From the nutrient solution. Even in soil the plant only takes up minerals when they’re dissolved in water. In the tower I add nitrogen, phosphorus, potassium, calcium, magnesium and trace elements to the water specifically via the nutrient, plus light, air and carbon dioxide.
Are nutrients and vitamins the same thing?
No. Nutrients in the nutrient solution are dissolved minerals that the roots take up. Vitamins are organic compounds that the plant forms itself. So you don’t add vitamins to the tower, but the building blocks from which the plant makes them.
Does pak choi take up the nutrient directly into the leaves?
No. The roots take up water and dissolved nutrients, the plant distributes and processes them. That’s why EC and pH have to be right. More nutrient doesn’t make the pak choi richer in nutrients, it only stresses the roots.
Can you taste the hydroponic nutrient in pak choi?
Not with a correctly mixed nutrient solution. A bitter taste is more likely due to variety, heat, beginning flowering, age or a far too strong solution. The nutrient solution stays at the roots, rinse the leaves before eating.
Is hydroponic pak choi artificial?
No. It grows from a seed, forms roots and leaves and photosynthesises like any plant. The only difference is that the minerals come from a nutrient solution instead of soil water.
Is hydroponics just chemistry?
Hydroponics works with water, light, air and dissolved minerals. They can be described chemically, just like water and nutrients in garden soil. The plant takes up the same basic building blocks, only dosed more precisely.
Is mineral hydroponic nutrient harmful?
Not when used correctly. It supplies the necessary elements in water-soluble form. Damage comes from wrong products, heavy overdosing or an unsuitable pH, that’s why I use nutrients for hydroponics and edible plants and check with the EC meter.
How do I describe my growing?
I explain honestly how my plants grow: without soil, with a controlled nutrient solution and under my own conditions. Instead of using labels, I’d rather show you what’s really in the water and how I work.
Is hydroponic pak choi less natural?
No. Pak choi remains a real plant with seeds, roots, leaves and photosynthesis. The tower only changes the root zone and the supply. Whether someone personally finds the method natural is a judgement, the growth processes are the same.
Do harmful nutrient residues remain in pak choi?
The plant takes up dissolved nutrients and processes them, that’s not a layer of nutrient on the leaf. I only use hydroponic nutrient for edible plants, keep to the target values and don’t spray nutrient solution on the leaves. Rinse thoroughly before eating.
Is hydroponic pak choi fit to eat?
Yes, if it was grown with suitable nutrient, clean water and clean parts. Remove diseased or slimy plant parts and harvest with clean hands and tools. With mould or a rotten smell, stop harvesting.
Do I have to wash pak choi from the hydro tower before eating?
Yes. Home-grown pak choi can also carry dust, splashes or small insects. Separate the leaves, rinse them in cold water and look especially at the undersides. Soap or cleaners don’t belong on food.
What do flavour and leaf quality of pak choi depend on?
On variety, light, temperature, nutrient supply, water, age of the plant and harvest time. Heat and a beginning flower stalk make it more bitter, too little light makes the leaves thin and soft. The growing system alone doesn’t decide the flavour.
Does pak choi from soil generally taste better than from hydroponics?
That can’t be said across the board. A well-lit, properly supplied pak choi in the tower can be fresh and crunchy, a poorly supplied one in soil weak or bitter. For a fair comparison, variety, age, light, temperature and harvest time would have to be the same.
How long does the pump run in the hydro tower?
Indoors 5 minutes on and 30 minutes off, that’s enough, the roots stay moist. Outdoors in great heat 15 minutes on and 15 off. If the leaves droop, the pause is too long. The air pump doesn’t go on the timer, it runs constantly.
Roughly how much electricity does the water pump cost?
Power and run time are what matter. At 5 minutes on and 30 off the pump runs around 3.4 hours a day. A 5 watt pump then uses about 0.5 kWh a month, an 8 watt pump about 0.8 kWh, so at 30 cents per kWh only 15 to 25 cents. Measure it exactly with an energy meter plug.
Why is a spare pump useful?
If the pump fails, you swap it immediately and the roots don’t dry out. Ideally use the same model with matching lift height and the same connection. You can also use it to pump out the reservoir. Always unplug before working on the pump.
Why are the roots brown or smell unpleasant?
Usually the water is too warm, above 25 °C it hardly holds oxygen. Check water temperature, water flow, pump and air pump. Remove loose root remains, clean the reservoir and mix fresh nutrient solution if it doesn’t improve quickly.
What do healthy pak choi roots look like?
Light, firm and with a neutral smell. Slight discolouration from nutrient isn’t a problem. Dark, slimy, soft or rotten-smelling roots on a weakening plant are a warning sign, then check temperature, oxygen and water flow.
Why do algae form in the tank or at free openings?
Algae need light, water and nutrients. Close free openings with cover caps and keep the reservoir light-proof. Remove deposits early and clean the tank thoroughly with every fresh mix.
How do I clean the hydro tower hygienically?
Remove wilted leaves and loose root remains immediately. When restarting, clean tank, lid, net pots and reachable parts with lukewarm water and a soft brush and rinse well. Don’t point hot steam at PETG parts, don’t use abrasive cleaners.
Can I extend the hydro tower or make it smaller in winter?
Yes. With single segments you extend the HydroFlex Tower, in winter you can also build it shorter. Check beforehand that it stands securely and the pump still brings enough water to every opening at the top. If you have questions about your tower, just write to me on WhatsApp.
What is hydroponics?
In hydroponics the plant grows without soil. The roots get water, nutrients and oxygen directly from the nutrient solution. In the hydro tower the pump pushes the water up, from there it runs through the levels back into the reservoir.
What do leaf, fruit and root vegetables mean?
The terms describe the part of the plant you harvest. Lettuce and pak choi are leaf vegetables, tomatoes and peppers fruit vegetables. With radishes you harvest the thickened root, with kohlrabi a thickened stem tuber.
Why don’t kohlrabi and radishes get bloom nutrient?
Because with both you harvest before flowering, the tuber or the storage root. Until then growth is the focus, a balanced growth nutrient suits better than one that promotes flowering. That’s why, like pak choi, they stay on my liquid nutrient.
