Mills Nutrients - pH Flower - 1 Litre - Lowers Reservoir pH for the Flowering Stage
Best for: Growers who need to bring reservoir pH down into range during flowering without introducing a separate unmatched pH-down product.
Our thoughts
Every grower needs a pH-down at some point, tap water and nutrient concentrates almost always push pH up over time. Mills pH Flower does the one job it's meant for and nothing more. Simple, reliable feeding that delivers results.
Mills pH Flower is a phosphoric acid-based pH reducer, made up of roughly 59% phosphoric acid and 42.5% phosphorus oxide (P2O5), designed to bring reservoir pH down during the flowering stage. Add it to your nutrient reservoir whenever the pH has drifted above your target range, typically 5.8-6.2 for flowering crops in hydro or coco, and it lowers pH while also contributing a small amount of usable phosphorus rather than acting as dead weight in the mix.
It's designed to be used alongside the rest of the Mills range, including in the Mills Full Coco Kit, but works as a standalone pH corrector with any base nutrient. Add it gradually and re-test, phosphoric acid-based pH-down products can overshoot if dosed too heavily in one go.
How it compares
Phosphoric-acid pH-down products are the standard approach across the industry.
- Versus House & Garden's pH-down, both use a phosphoric acid base and work the same way; Mills is formulated to match the rest of the Mills feeding range.
- Versus General Hydroponics pH Down, dosing behaviour is broadly similar since both rely on phosphoric acid as the active ingredient.
- Versus using raw phosphoric acid concentrate, a formulated product like this is easier to dose accurately without risking a big pH swing.
It does the same job as most pH-down products on the market, the main reason to pick this one is running it alongside the rest of the Mills coco or hydro range.
Usage guidance
Small, gradual additions with re-testing between doses is the safest approach with any phosphoric acid pH-down.
Dosing
Add a small amount to your reservoir, mix thoroughly, then re-test pH before adding more. Target 5.8-6.2 for flowering in most hydro and coco setups.
When to use it
Check reservoir pH daily during flower, tap water and nutrient concentrates both tend to push pH upward over a few days.
Storage
Keep the bottle tightly capped and away from metal fittings, phosphoric acid is corrosive to some metals over time.
Technical specifications
- Active ingredient: Phosphoric acid (approx. 59%)
- Phosphorus oxide (P2O5) content: Approx. 42.5%
- Target pH range: 5.8-6.2 for flowering
- Growth stage: Flowering
- Bottle size: 1 Litre
- Manufacturer: Mills Nutrients, Netherlands
Who this is for
- Growers running Mills Basis A/B or the Mills Full Coco Kit who want a matched pH-down
- Anyone whose reservoir pH consistently drifts upward during flower
- Hydro and coco growers needing to hold pH in the 5.8-6.2 range
- Growers who want a formulated pH-down rather than dosing raw acid
Not needed if your water naturally sits in range or you're already using another brand's matched pH-down.
Our take
It's a no-frills pH corrector that does exactly what the name says, useful to have on the shelf during flower whether or not you're running the rest of the Mills range.
Worth picking up alongside your base nutrient rather than waiting until pH drifts out of range mid-flower.
