IONIC Feed Chart
IONIC gives every growing medium its own Grow and Bloom rather than stretching one base across all of them, and hard water gets a separate range again. All four charts are below, straight from Growth Technology's 2026 schedules, with the target EC on every week. Underneath them, our free calculator fits whichever one you are running to your pot size, plant count and cycle length, and works out how much you actually need to buy.
Which IONIC range am I on?
Four charts, and the one you want is decided by your medium and your tap water rather than by preference.
- Coco. Coir. Switches to Bloom a week later than most charts, and finishes on a light feed rather than plain water.
- Soil. The humic-rich Soil Grow and Bloom. Tonic runs at half the coco rate and only in bloom.
- Hydro, soft or RO water. Rockwool, NFT, DWC, anything inert on water that starts low.
- Hydro, hard water. The same media on hard mains supply. Different bottles and a different chart.
If you are in coco or soil, that is the whole decision. If you are in rockwool or running a system, check your water before you order, because the hard water range is not the soft water one with something added.
The IONIC Coco feed chart
Millilitres per litre of water. Veg here is four weeks and flower nine, which is the commonest UK cycle. If yours is longer or shorter, the calculator fits the same schedule to it rather than simply running out.
Swipe the chart sideways to see every week.
| Week | Coco Grow | Coco Bloom | Tonic | PK | Root Boost | Flower Boost | Target EC |
|---|---|---|---|---|---|---|---|
| Veg week 1 | 5 | – | – | – | 0.75 | – | 1.0 |
| Veg week 2 | 5 | – | – | – | 0.75 | – | 1.0 |
| Veg week 3 | 5 | – | 1 | – | 0.75 | – | 1.4 |
| Veg week 4 | 5 | – | 1 | – | 0.75 | – | 1.4 |
| Flower week 1 | 5 | – | 1 | – | – | 0.75 | 1.4 |
| Flower week 2 | – | 7 | 1 | – | – | 0.75 | 1.7 |
| Flower week 3 | – | 7 | 1 | – | – | 0.75 | 1.7 |
| Flower week 4 | – | 7 | 1 | 1 | – | 0.75 | 2.0 |
| Flower week 5 | – | 7 | 1 | 1 | – | 0.75 | 2.0 |
| Flower week 6 | – | 7 | 1 | 1 | – | – | 2.0 |
| Flower week 7 | – | 7 | – | 1 | – | – | 2.0 |
| Flower week 8 | – | 7 | – | 1 | – | – | 2.0 |
| Flower week 9 | – | 1 | – | – | – | – | – |
Target pH 5.8 to 6.2. Root Boost and Flower Boost print as a range of 0.5 to 1 ml/L; the figure shown is the 0.75 midpoint. The last week is a light feed at 1 ml/L, not plain water. That is how IONIC print it.
The IONIC Soil feed chart
Sits slightly above coco on EC early and slightly below it at the peak. It steps up to the heavier Grow rate in veg week 3, where coco holds at 5 ml all the way to the flip. Tonic comes in later than it does on coco, and at half the dose.
Swipe the chart sideways to see every week.
| Week | Soil Grow | Soil Bloom | Tonic | PK | Root Boost | Flower Boost | Target EC |
|---|---|---|---|---|---|---|---|
| Veg week 1 | 5 | – | – | – | 0.75 | – | 1.1 |
| Veg week 2 | 5 | – | – | – | 0.75 | – | 1.1 |
| Veg week 3 | 7 | – | – | – | 0.75 | – | 1.3 |
| Veg week 4 | 7 | – | – | – | 0.75 | – | 1.3 |
| Flower week 1 | 7 | – | – | – | – | 0.75 | 1.3 |
| Flower week 2 | – | 7 | 0.5 | – | – | 0.75 | 1.5 |
| Flower week 3 | – | 7 | 0.5 | – | – | 0.75 | 1.5 |
| Flower week 4 | – | 7 | 0.5 | 1 | – | 0.75 | 1.9 |
| Flower week 5 | – | 7 | 0.5 | 1 | – | 0.75 | 1.9 |
| Flower week 6 | – | 7 | 0.5 | 1 | – | – | 1.9 |
| Flower week 7 | – | 7 | – | 1 | – | – | 1.9 |
| Flower week 8 | – | 7 | – | 1 | – | – | 1.9 |
| Flower week 9 | – | 1 | – | – | – | – | – |
Target pH 5.8 to 6.2.
The IONIC Hydro feed chart, soft or RO water
Starts higher than coco or soil, because inert media hold nothing back for the plant and the whole feed has to come out of the tank. Only the hard water chart below sits above it.
Swipe the chart sideways to see every week.
| Week | Hydro Grow | Hydro Bloom | Tonic | PK | Root Boost | Flower Boost | Target EC |
|---|---|---|---|---|---|---|---|
| Veg week 1 | 5 | – | – | – | 0.75 | – | 1.5 |
| Veg week 2 | 5 | – | – | – | 0.75 | – | 1.5 |
| Veg week 3 | 5 | – | – | – | 0.75 | – | 1.5 |
| Veg week 4 | 6 | – | – | – | 0.75 | – | 1.9 |
| Flower week 1 | 6 | – | – | – | – | 0.75 | 1.9 |
| Flower week 2 | – | 6 | 0.5 | – | – | 0.75 | 1.9 |
| Flower week 3 | – | 6 | 0.5 | – | – | 0.75 | 1.9 |
| Flower week 4 | – | 5 | 0.5 | 1 | – | 0.75 | 2.1 |
| Flower week 5 | – | 5 | 0.5 | 1 | – | 0.75 | 2.1 |
| Flower week 6 | – | 5 | 0.5 | 1 | – | – | 2.1 |
| Flower week 7 | – | 5 | – | 1 | – | – | 2.1 |
| Flower week 8 | – | 5 | – | 1 | – | – | 2.1 |
| Flower week 9 | – | 1 | – | – | – | – | 2.1 |
Target pH 5.8 to 6.2. On hard tap water use the chart below instead.
The IONIC Hard Water feed chart
This is the one most British growers on mains water want, and it is worth understanding why it exists.
Hard water carries bicarbonates. They act as a buffer, which is why your pH creeps up over the week however carefully you set it on mixing day. The hard water bottles are formulated around that rather than fighting it, so the range starts at an EC of 1.9 where the soft water chart starts at 1.5.
There is no Tonic on this chart at all. IONIC say to use it on this range only where a calcium or magnesium deficiency actually shows, at 0.5 ml/L for a single week, which makes it a fix rather than a schedule row. And the run finishes on plain water.
Swipe the chart sideways to see every week.
| Week | Hard Water Grow | Hard Water Bloom | PK | Root Boost | Flower Boost | Target EC |
|---|---|---|---|---|---|---|
| Veg week 1 | 5 | – | – | 0.75 | – | 1.9 |
| Veg week 2 | 5 | – | – | 0.75 | – | 1.9 |
| Veg week 3 | 5 | – | – | 0.75 | – | 1.9 |
| Veg week 4 | 6 | – | – | 0.75 | – | 2.3 |
| Flower week 1 | 6 | – | – | – | 0.75 | 2.3 |
| Flower week 2 | – | 6 | – | – | 0.75 | 2.3 |
| Flower week 3 | – | 6 | – | – | 0.75 | 2.3 |
| Flower week 4 | – | 5 | 1 | – | 0.75 | 2.5 |
| Flower week 5 | – | 5 | 1 | – | 0.75 | 2.5 |
| Flower week 6 | – | 5 | 1 | – | – | 2.5 |
| Flower week 7 | – | 5 | 1 | – | – | 2.5 |
| Flower week 8 | – | 5 | 1 | – | – | 2.5 |
| Flower week 9 | – | – | – | – | – | – |
Target pH 5.8 to 6.2.
Mix to the EC, not to the millilitres
The doses above assume your water starts at zero. UK tap water usually sits between 0.3 and 0.5 EC before you add anything, and that counts towards the targets in the last column.
So on tap water you will reach the chart's own EC with slightly less nutrient than it prints. Use the doses to get close and the meter to know. On RO, the printed figures are the ones to run.
This matters more on IONIC than on most ranges, because the hard water chart is already pitched high. Starting at 1.9 with 0.5 coming out of the tap leaves you less headroom than the numbers suggest.
What a full IONIC run costs
For a common UK setup, nine plants in 3 gallon Quick Fill coco bags, four weeks of veg and nine of flower, the coco chart comes to about £264 across 6 products, mixing roughly 1,500 litres of feed.
Where that money goes is the interesting part. The base feed, Coco Grow and Coco Bloom together, is about £104. The two boosters are £120 between them: Flower Boost at £72 and Root Boost at £48. So more than half the bill is the stimulants rather than the food.
Both of those are optional in the calculator. Untick them and the same grow lands near £144. We are not going to tell you which way to go on that, but you should see the split before you order rather than after.
The other three come out lower, though mostly because those media drink less rather than because the feed is cheaper. Nine plants in soil at the same pot size mix about half the water coco does, and land near £190. On a rockwool slab the soft water chart is also around £190. The hard water chart on the same slab is £168, which is exactly one bottle of Tonic less, because it does not use any.
The calculator prices your actual grow rather than this example, and prices the other sixteen brands alongside it.
What you need for an IONIC run
Coco, as the example above. Swap the two base bottles for the soil, hydro or hard water pair if that is what you are in.
- IONIC Coco Grow
- IONIC Coco Bloom
- IONIC Tonic
- IONIC PK
- IONIC Root Boost (optional)
- IONIC Flower Boost (optional)
The full IONIC range is twelve products. Or let the calculator work out the sizes and quantities for your own grow and put the lot in your basket in one click.
The Hydro Bros is not affiliated with, endorsed by or approved by IONIC or Growth Technology. The figures above are transcribed from their own published feed charts. Where a chart prints a range, the midpoint is shown, and it says so. They are a starting point rather than a prescription: read your own runoff and your own meter, and adjust to your room.
