Quick answer: A nutrient feed chart is a week-by-week table. Each column is a stage or week of growth, each row is a product, and the numbers are usually millilitres per litre of water. Many charts also give a target EC (feed strength) and pH for each week. Read down the column for the week you are in, add products in the order listed, check EC, then adjust pH last. Treat the chart as a maximum, not a target, and adjust to how your plants look.
Why feed charts look complicated
Every nutrient brand publishes a feed chart, sometimes called a feeding schedule. They pack a lot of information into a small space, and they assume you know the jargon. Once you understand the layout, though, almost all of them work the same way.
If you want background on what A and B base nutrients and additives actually do, see our earlier guide on hydroponic nutrients explained. This guide is about reading the chart itself.
The layout: columns, rows and numbers
Columns: stages and weeks
Across the top you will usually see the stages of growth:
- Propagation or start: seedlings and cuttings.
- Vegetative or growth: the leafy stage. Many charts show this as one column, because it can run as long as you need. BioBizz say this on their own chart.
- Flowering or bloom, week 1, 2, 3 and so on: counted from the point you switch your plants into flowering or fruiting.
- Flush or final week: often plain water or a finishing product.
Your plants may not follow the chart's timings exactly. A quick-maturing tomato and a slow chilli will not finish in the same week. Line the chart up with what your plants are doing, not just the calendar.
Rows: products
Each row is a product, typically in this order: base nutrients first (often a Part A and Part B, or a grow and bloom feed), then any root stimulators, then boosters and additives. The order is often the order you should add them to the water.
The numbers: dose rates
Most charts give ml per litre. Some give ml per 10 litres, or grams per litre for powders, so always check the units in the corner of the chart. For example, Canna Terra Vega is listed at 50ml per 10 litres, which is the same as 5ml per litre.
A dash or blank cell means you do not use that product that week.
Understanding EC
EC stands for electrical conductivity. Dissolved nutrients conduct electricity, so EC tells you how strong your feed is. Most charts quote it in mS/cm (some use CF or ppm instead; CF is simply EC multiplied by 10).
- Low EC: a weak feed. Right for seedlings and cuttings. Canna Start, for example, gives an EC of roughly 0.7 to 1.3 depending on your tap water.
- Higher EC: a stronger feed, used as plants get bigger and hungrier.
Pay attention to whether the chart's EC includes your tap water. Canna state that their Terra Vega target of 0.9 to 1.6 mS/cm includes the tap water's own EC. Midlands tap water already has some minerals in it, so measure your plain water first to know your starting point.
A Bluelab Truncheon nutrient meter is a simple way to check this; Bluelab say it does not need calibrating.
Understanding pH
pH tells you how acidic or alkaline your feed is. It matters because plants can only take up certain nutrients within a certain pH range. Get it wrong and the plant can go hungry even when the food is in the water.
Feed charts and labels normally give a target range. Canna, for example, recommend pH 5.8 to 6.2 for Terra Vega in soil, and around 5.5 to 6.2 for their Coco Professional Plus substrate. Mills recommend 5.5 to 6.5 for most plants. Follow your own nutrient brand's figures.
Measure with a calibrated meter such as the Bluelab pH Pen and adjust with pH Down or pH Up, adding a little at a time and re-testing.
Mixing a feed from the chart, step by step
- Find your week. Pick the column that matches your plants' stage.
- Measure your water. Use a measuring jug or a marked watering can so your ml-per-litre maths is right.
- Shake every bottle. Ingredients settle.
- Add products one at a time, in order. Stir between each. With two-part feeds, add Part A, stir, then Part B. Never pour concentrates into each other.
- Check EC. If it is higher than the chart says, add more water. If lower, and your plants look hungry, you can increase slightly.
- Adjust pH last. Additives can shift pH, so always check after everything is in. Canna note that adding Rhizotonic may slightly raise pH, for example.
Common chart terms explained
- PK booster: a phosphorus and potassium supplement used in flowering. Canna PK 13/14 is used either for a short burst around three weeks before harvest, or at a low "trickle" dose from around weeks 2 to 3 of flowering. Always add it after base nutrients.
- Enzymes: products such as Cannazym that break down old root material. Canna advise not mixing Cannazym with hydrogen peroxide.
- Root stimulator: used mainly early on and after transplanting, for example Canna Rhizotonic.
- Flush: plain water or a flushing product at the end of the cycle.
- Soft water / hard water (SW/HW): some ranges come in versions for each, as the mineral content of your tap water affects the balance. Ask us which suits your area.
Tips from the shop counter
- Start low. Many experienced growers start at half to three-quarters of the chart dose and build up. BioBizz put it simply on their chart: be modest rather than generous.
- Read your plants. Burnt, crispy tips usually mean the feed is too strong. Pale lower leaves can mean the plant wants more.
- Do not mix brands without thinking. A chart is designed for that brand's products. Adding extras from other ranges can push EC too high.
- Write it down. Note the date, week, doses, EC and pH each time. It makes problems much easier to solve.
FAQs
Do I have to use every product on the chart?
No. The base nutrients are the essentials. Additives are optional extras, and many growers get good results with base feed alone plus careful pH and EC control.
What if my EC reads higher than the chart before I add anything?
That is your tap water. Either subtract it from your target (if the chart's figure excludes tap water) or allow for it (if it includes it). Check the chart's small print.
Can I use a soil chart for coco?
No. Use the chart written for your medium. Coco and hydro charts are designed around different nutrients and targets.
Where do I find the feed chart for my nutrients?
Most brands publish their charts on their official websites, and many print a simplified version on the bottle. If you are stuck, bring the bottle in and we will go through it with you.
Want help with your feed?
Bring your bottles, or just a photo of your plants, to our shop at Unit 2 BlackLake, West Bromwich, B70 0PJ. You can also call 0121 553 7872 or WhatsApp us. Browse our base nutrients. Free UK delivery over £99, and we price match.