Mills Feed Chart – High Concentrate, Osmosis Water

Mills Nutrients' own published High Concentrate schedule for reverse-osmosis water. Week by week, in millilitres per litre.

Mills print four versions of this schedule and they are not interchangeable. Two are for the Regular bottles and two for the thicker High Concentrate bottles, and each of those comes in a tap-water and a reverse-osmosis version. So check the label on the bottle you own, then check what you are filling the tank with. This page is High Concentrate on RO water. The other three sit on our feed chart index.

Mills High Concentrate feed chartOsmosis water · coco, hydro or soil · tap to enlarge

Download the PDFOpen full size

• All dosesper 1 litre
• pH5.5 – 6.5
• Base feed0.6–2ml of each of A and B

Basis A and Basis B always go in at the same amount as each other. The week number starts again at 1 when flowering begins.

Every figure is millilitres per one litre of water, not per ten. A 10-litre watering can needs ten times these numbers, so 1.9ml of Basis A becomes 19ml. Get that wrong and the feed is ten times too weak.

Getting it right

• Read the dose as per litre. Most brands print per 10 litres, Mills print per litre. It is the single easiest mistake to make with this chart.
• This is the RO chart. It assumes water that has been through a reverse-osmosis filter and reads EC 0.0. On ordinary tap water the same bottles are dosed differently, because the tap is already supplying some of the calcium and magnesium.
• High Concentrate is not the Regular line. Same names on the labels, much stronger liquid, far smaller doses. Never run one line's numbers with the other line's bottles.
• One chart covers coco, hydro and soil. Mills say so themselves, which is unusual — most brands publish a separate schedule per medium. The medium changes how often you water, not how much goes in the tank.
• Mixing order matters. Vitalize goes into the water first, then Basis A, then Basis B in the same amount, then the stimulants. Never pour two concentrates together before they hit the water.
• Keep pH between 5.5 and 6.5 and expect EC to climb from about 1.3 in early growth to about 2.8 at peak bloom. Set the strength first, correct the pH after.
• Grow is only two weeks on this chart. If you veg for longer, hold the Grow 2 figures until you flip the lights, then start at Flower 1.

Everything on the chart

Common questions

Which of the four Mills charts do I need?

Two questions. First, are your bottles Regular or High Concentrate — it says so on the label. Second, is your water straight from the tap or through an RO filter. That gives you one chart of the four, and this one is High Concentrate on RO water. All four are listed on our feed chart index.

Does this really work in soil as well as coco and hydro?

Yes. Mills publish a single schedule and state it can be used on all mediums. What changes between them is watering frequency and how much runoff you aim for, not the amount of nutrient in the tank.

What does 1.9ml per litre mean in a watering can?

Multiply by however many litres the can holds. A 5-litre can takes 9.5ml, a 10-litre can takes 19ml. A 1ml syringe or a small measuring cup is worth having for the smaller figures.

Why is the base feed sold as two bottles?

Calcium in one bottle and sulphates and phosphates in the other would form a solid if they were stored together. Kept apart and added to a full tank one after the other, they stay in solution. That is also why they are never poured into each other neat.

Do I need a separate CalMag with this?

Mills do not put one on the chart. Basis A carries the calcium and magnesium, and on RO water the doses here are already higher than the tap-water chart to make up for what the filter took out.

Shop the full Mills range

Figures as published by Mills Nutrients on their own growth charts page, mills-nutrients.com. Always read the label on the bottle you own. Mills Nutrients is a trade mark of its owner.