Growth Technology pH Up - Potassium Hydroxide Solution to Raise Nutrient pH
Best for: hydro, coco and soil growers whose nutrient solution has drifted too acidic and needs bringing back up into range.
Our thoughts
The less glamorous other half of the pH pairing, but just as necessary - if your feed's tested too acidic, this is what brings it back up. Growth Technology's version is a straightforward potassium hydroxide solution, dosed sparingly and tested as you go.
Growth Technology pH Up is a concentrated potassium hydroxide solution (around 25% strength) used to raise the pH of nutrient solution in hydroponic, coco or soil-based growing. Nutrient solutions can run too acidic depending on your water source, base nutrients and additives, and most plants want a feed pH somewhere around 5.5 to 6.5 to take up nutrients properly.
As with any pH adjuster, it's added in small amounts to the mixed nutrient solution and checked with a meter or drops kit after each addition, rather than dosed by eye or guesswork.
How it compares
pH Up solutions across the nutrient brands are broadly similar in function, with strength and bottle size being the main differences.
- Compared with General Hydroponics pH Up, which is also potassium-hydroxide based, the two work in essentially the same way and at similar dose rates.
- Compared with Canna pH+, another alkaline adjuster, the practical choice usually comes down to price and pack size rather than performance.
- Compared with using baking soda as an improvised fix, a purpose-made pH Up gives a predictable, repeatable strength every time, rather than variable results.
It's not a fancy product, but a correctly labelled, consistent-strength pH Up is worth more than saving a couple of pounds on an unknown alternative when you're dosing a whole reservoir.
Usage guidance
Dose gradually and always test as you go.
Dosing
Add a few drops at a time to your mixed nutrient solution, stirring and re-testing pH until you reach the target range of roughly 5.5-6.5.
Handling
This is a strong alkaline solution - wear gloves and eye protection, and rinse immediately with clean water if it contacts skin, eyes or clothing.
Storage
Store the bottle sealed and upright, out of reach of children and pets, away from direct heat or sunlight.
Technical specifications
- Active ingredient: potassium hydroxide, approx. 25%
- Function: raises nutrient solution pH
- Sizes available: 250ml, 1L and 5L bottles
- Brand: Growth Technology
- Compatible systems: hydroponics, coco coir, soil
- Target feed pH range: approx. 5.5-6.5 (varies by plant/media)
Who this is for
- Any grower running a hydro, coco or soil system who needs to manage feed pH
- Growers whose water source or nutrient line tends to run acidic
- New growers building their first pH testing and correction kit
- Anyone topping up an existing pH Up/Down pairing
Our take
You won't need pH Up as often as pH Down in most UK tap water setups, but when you do need it, you need it to work properly and predictably - which this does.
Does exactly what it should, day in, day out - worth keeping a bottle in the cupboard alongside your pH Down and testing kit.
