BioBizz pH Down (Bio-Down)

BioBizz pH Down (Bio·Down™) is an organic pH regulator for lowering the pH of your nutrient solution. It is an aqueous solution of citric acid, the natural acid found in citrus fruits such as lemons, made especially for organic growers.

Key benefits

• Correcting pH lets plants take up the maximum amount of nutrients
• Fast pH adjustment for any type of substrate and any crop
• No strong acids, so it is gentle on the micro life in your substrate
• Designed to work with all BioBizz nutrients and substrates
• Use in every watering, through both the growing and flowering periods

How to use

• Mix your BioBizz nutrients first, then measure the pH of the mix.
• Add Bio-Down a little at a time (BioBizz guide: 0.1 ml lowers the pH by about 0.5 points), stir for 10 seconds and measure again.
• Repeat until you reach the ideal range of pH 6.2 to 6.5, then water your plants.
• Keep at room temperature, away from direct light, and out of the reach of children.

Sizes

• 250ml bottle
• 500ml bottle
• 1 litre bottle
• 5 litre can

Feed chart

The official BioBizz Nutrient Schedules recommend Bio-Down if you have hard water. Both official 2026 BioBizz Nutrient Schedules (All-Mix, and Light-Mix or Coco-Mix) are shown in the product images.

• BioBizz Nutrient Schedule 2026: All-Mix and Light-Mix / Coco-Mix schedules (PDF)
• Peat-free growing: BioBizz peat-free Nutrient Schedule

Feed charts are a guide only; adjust to your plants, water and conditions.

More information: Bio-Down on biobizz.com · Bio-Down product data sheet (PDF).

Delivery:

Dispatch cut off point 12:00pm

(if you order after this time you item will be dispatched the following working day)

Free carriage only apply's to the below if we can use royal mail if the item is to large we will call to discuss as there is other options available.

Postcodes Highlands: FK17-22, G83, IV1-28, IV33-39, KW1-3, KW5-14, PA21-33, PA35-40, PH18-26, PH30-42, AB44-56, IV30-32Islands: HS1-9, IV40-51,IV55-56,KA27,KA28,KW15-17,PA20,PA34,PA41-48,PA60-78,PH42-44,ZE1-3, JE, GY, IM, TR21-25 (ALL ISLANDS APPLY) Northen Ireland: BT