Understanding Hydroponic Nutrients
Nutrients are often the part of hydroponics that makes people pause. Bottles, measurements, pH, strength — it can sound like a lot at first. But once you understand what actually matters, feeding your tower becomes much simpler.
In a traditional garden, plants draw nutrients from the soil. In a hydroponic system, those nutrients are delivered through the water instead.
That is what FlowGrow nutrients are doing. They provide the essential minerals your plants need to grow, while the tower keeps water moving through the system so roots can access water, nutrients, and oxygen.
Hydroponic nutrients provide the minerals plants would usually draw from soil.
The nutrient water moves through the tower, helping roots access what they need as they grow.
The simple version: hydroponic nutrients are plant food mixed into water. You do not need to memorise every mineral to grow successfully at home.
What do hydroponic nutrients actually do?
Plants need nutrients to support root growth, leaf growth, stem strength, flowering, and fruiting. In soil, these nutrients come from the ground. In hydroponics, they come from a carefully balanced nutrient solution.
FlowGrow nutrients are designed to be simple and repeatable for home growers. The aim is not to turn growing into a science project. It is to give your plants a steady, balanced feed that supports healthy growth in real home conditions.
Helpful to know
You do not need to understand every ingredient to get started. What matters most is mixing correctly, using equal parts A and B, keeping water topped up, and refreshing your reservoir when needed.
Why are there two bottles, A and B?
FlowGrow uses a two-part nutrient system. This means the nutrients come in two bottles: Part A and Part B.
This is not to make things harder. Some nutrients need to be kept separate in concentrated form so they stay stable and available for your plants. If everything was combined into one strong concentrate, some elements could bind together and become less useful.
Add to water first
Add Part A to your reservoir water, then mix gently before adding Part B.
Add separately
Add Part B after Part A has been diluted into the water. Never mix concentrates together directly.
Important: always add nutrients to water. Never mix concentrated Part A and Part B together before adding them to your reservoir.
How much nutrient do you actually use?
For FlowGrow, all standard feeding guidance is based on the recommended 15 litre working reservoir.
Starting gently is often better than overfeeding, especially when plants are young or newly moved into the tower.
| Plant stage | Part A | Part B | Approx. EC | Helpful to know |
|---|---|---|---|---|
| Seedlings | 15 ml | 15 ml | ~0.2 | A gentle mix for young seedlings and early root growth. |
| Leafy greens and herbs | 40 ml | 40 ml | ~0.5 | A balanced everyday mix for lettuce, herbs, and similar leafy crops. |
| Plants growing strongly | 80 ml | 80 ml | ~1.0 | For plants with healthy roots, steady new leaves, and stronger growth. |
There is no rush to move to stronger feeding. Young plants usually do better with a gentler start, then you can increase nutrient strength as roots establish and growth becomes more active.
For a simple step-by-step dosing guide, read the FlowGrow Feeding Guide.
Grow nutrients vs Bloom nutrients
Different plants need different support as they grow. Leafy greens and herbs mainly focus on leaves, stems, and roots. Fruiting plants eventually shift energy into flowers, buds, and fruit.
For leafy growth
Grow nutrients are used for seedlings, leafy greens, herbs, and early plant growth. They support root development, stems, and fresh leaf growth.
View Grow Nutrients
For flowering and fruiting
Bloom nutrients are used when plants begin to flower, form buds, or fruit. This can include strawberries, compact tomatoes, and chillies.
View Bloom NutrientsMany home growers start with leafy greens and herbs first, then experiment with fruiting plants as their confidence grows.
What happens as water levels drop?
As your plants grow, they use water and absorb nutrients. But they do not always use both at exactly the same rate.
This means that as the water level drops, the nutrient strength in the reservoir can slowly change. In warm weather or during faster growth, water may also disappear more quickly.
This is normal in a recirculating system. The easiest habit is to check your water level regularly, top up when needed, and refresh the reservoir every few weeks depending on plant size, water use, and growing conditions.
Helpful rhythm: top up water regularly, check how your plants look, and refresh your reservoir when the system needs a clean reset.
What is EC?
EC stands for electrical conductivity. In simple terms, EC is a way of measuring how strong your nutrient water is.
A lower EC means a gentler nutrient mix. A higher EC means the water contains more dissolved nutrient.
The FlowGrow dosing system has been designed around real home use and practical EC testing. If you follow the standard feeding guidance, you are already working with gentle, balanced nutrient strengths.
If you want to understand EC more clearly, read our guide to pH and EC for home hydroponic growing.
Stability matters more than perfection
You do not need to measure constantly or chase exact numbers every day. For most home growers, steady conditions are more helpful than constant adjusting.
Good light, regular water top-ups, balanced nutrients, and simple observation will usually tell you far more than trying to perfect every reading.
When an EC meter can help
You do not need an EC meter to get started with FlowGrow. But as your plants grow, or if you want a clearer picture of what is happening in your reservoir, an EC meter can be useful.
- It can help you check nutrient strength.
- It can show changes as water levels drop.
- It can support small, confident adjustments over time.
It is best seen as a helpful learning tool, not something that needs to make growing feel complicated.
You can explore simple testing options in our Helpful Growing Extras.
What about pH?
pH is about how easily your plants can access nutrients in the water.
Most home hydroponic vegetables and herbs grow well when the nutrient water sits somewhere around pH 5.5 to 6.5.
If pH moves too far outside this range, nutrients may still be in the water, but your plants may struggle to absorb them properly.
How to keep pH simple
Use pH strips or a digital meter to check occasionally. If you need to adjust, make small gradual changes rather than trying to force a perfect number.
A small note on water temperature
Water temperature can make a difference over time, especially during warmer months.
Plants generally do best when the reservoir water stays cool to slightly room temperature. If water becomes too warm, it can hold less oxygen, which may make it harder for roots to stay healthy.
You do not need to manage this closely. Keeping your reservoir out of harsh direct heat and placing your tower in a bright but suitable growing position is usually enough.
Reading your plants
Your plants will usually give you clues about how things are going.
- Pale leaves can sometimes mean plants need more nutrients, better light, or a reservoir refresh.
- Brown leaf tips can sometimes mean the nutrient mix is a bit strong.
- Slow growth can be linked to light, temperature, young roots, or nutrient balance.
You do not need to react instantly to every small change. Observe first, then make simple adjustments one step at a time.
Keeping nutrients simple
You do not need to understand every nutrient detail to grow successfully at home.
You just need to:
- use equal parts A and B
- add nutrients to water, not directly together
- start gently while plants are young
- keep water topped up
- refresh the reservoir when needed
- check in on your plants regularly
Over time, this becomes part of the rhythm of growing. Instead of wondering if you are doing it right, you begin to understand what your plants need.
Frequently asked questions
Do I need to change nutrients every week?
No. You do not usually need to fully change nutrients every week. Top up water as needed and refresh the reservoir every few weeks depending on plant size, water use, and growing conditions.
Can I just top up water instead of adding more nutrients?
Yes, sometimes. Topping up water helps stop the nutrient mix becoming too strong as water levels drop. When you refresh the reservoir, add fresh nutrients using the recommended dosing guide.
What happens if I add too much nutrient?
Plants may show stress such as brown leaf tips, curling leaves, or slower growth. If you think the mix is too strong, refresh the reservoir with clean water and restart with a gentler dose.
Do I need an EC meter to grow successfully?
No. You can get started without an EC meter by following the FlowGrow feeding guide. An EC meter can be helpful as your confidence grows because it shows how strong your nutrient water is.
What is the difference between Grow and Bloom nutrients?
Grow nutrients support seedlings, leafy greens, herbs, and early growth. Bloom nutrients support flowering and fruiting plants such as strawberries, compact tomatoes, and chillies.
Why are my leaves turning yellow?
Yellowing leaves can happen for several reasons, including low light, nutrient imbalance, pH sitting outside the helpful range, or the reservoir needing a refresh. Start with the simple checks first.
Helpful next steps
Once nutrients start to make sense, home hydroponic growing feels much more manageable. These guides and products can help you keep learning at your own pace.
Read the Feeding Guide
Learn how much FlowGrow nutrient to use for seedlings, leafy greens, herbs, and plants growing strongly.
Understand pH and EC
Learn what pH and EC mean, why they matter, and how to keep home growing steady.
What can you grow?
Explore the herbs, leafy greens, and fruiting plants that suit home hydroponic towers.
Ready to keep growing?
FlowGrow nutrients are designed to make feeding your tower simple, balanced, and manageable at home.
