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pH Down
pH Down
pH Down
pH Down
pH Down
pH Down
pH Down
pH Down
pH Down

pH Down

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pH Down is a pH-adjusting solution formulated with food-grade phosphoric acid to lower nutrient solution pH.

pH Down helps bring nutrient solution into the proper pH range for plant uptake. It is designed for hydroponic and liquid-feed programs.

Mix nutrients into fresh water first, then add pH Down a little at a time. Stir, test, and repeat until the target pH is reached.

Even a strong nutrient recipe can underperform if pH is out of range. pH Down helps growers fine-tune solution pH so nutrients remain more available to plants.

Product guide

How to use this product

Review usage guidance, compatibility notes, and grower tips for this product.

Product Role

pH Down — What It Does

pH down
Brand: General Hydroponics
gh ph down, ph down, liquid ph down, liquid down, ph down
liquid, phosphoric acid, lower ph, acid, acidic, down liquids
pH Down
pH Down is a pH-adjusting solution formulated with food-grade phosphoric acid to lower
nutrient solution pH to the proper range. It’s widely recognized for consistent, reliable
performance in hydroponics and liquid-feed programs.

Usage Guide

pH Down — How to Use

● Add a little at a time, then test. Dose sparingly into your mixed nutrient solution,
stir, then re-test pH. Repeat until you reach target pH. Recommended pH for most
crops is 5.5–6.5.
● When to measure: Always adjust after nutrients are mixed into fresh water (don’t
pH-adjust concentrates).
● Tip: Use GH pH Test Indicator or a calibrated meter for verification.

Grower Benefits

pH Down — Key Benefits

● Food-grade phosphoric acid formulation.
● Reliable pH control for hydroponic and liquid-feed systems.
● Works alongside GH nutrient programs that target pH 5.5–6.5.Safety First
● Corrosive: Review the SDS before use; wear appropriate eye/skin protection and
handle in a ventilated area. Keep out of reach of children.
● Store upright in a cool, dry place. Avoid contact with bases/alkalis and never mix
with undiluted nutrient concentrates. (See SDS/Label.)

Safety First

pH Down — Resources & Safety

Store tightly sealed in a cool, dry place away from direct sunlight and extreme temperatures. Follow the product label and SDS for handling, PPE, storage, and disposal.
Resource links to include on the PDP: Safety Data Sheet, product label, and any feed chart or usage guide referenced for this product.

Support

Frequently Asked Questions

What is the warranty of pH Down?

General Hydroponics products are warranted to conform to label specifications at the time of purchase and for 1 year from that day. Misuse, mishandling, or storage outside recommended conditions voids warranty.

What is the shelf life of pH Down?

Under proper storage, expect full potency for about 2 years. Use opened products within one growing season.

Can I use this with any GH nutrient line?

Yes — use pH Down to maintain the recommended pH range across GH programs.

How much should I add?

Start small. Add a little, stir, test, and repeat until you hit your setpoint. Needed volume varies with water quality and recipe strength.

What is the expected shelf life, proper storage, and warranty of the pH Up and pH Down solutions?

Unopened bottles stored in a cool, dry place out of direct sunlight and away from extreme temperatures maintain full potency for approximately 2 years. Once opened, it is recommended to use the product within one growing season for the best and most consistent results. General Hydroponics warrants the products to conform to label specifications for 1 year from the date of purchase, though misuse, improper mixing, or incorrect storage voids this warranty.

How do I determine the correct dosage of pH Up or pH Down to add to my reservoir?

There is no single set dosage because the required volume varies depending on your starting water quality, source alkalinity, and specific nutrient recipe strength. The best practice is to add a very small amount at a time, stir or circulate the solution thoroughly, test the pH, and repeat until you reach your target setpoint.

What are the active chemical formulations used in General Hydroponics® pH Up and pH Down within the pH Control Kit?

Answer: pH Down is formulated with food-grade phosphoric acid to safely and reliably lower the pH of your nutrient solution. pH Up is formulated with potassium hydroxide and potassium carbonate to raise the pH of the solution when it runs too low.

What pH range should I aim for?

Most growers target pH 5.5–6.5 for nutrient availability.

Do I pH-adjust before or after adding nutrients?

After. Mix nutrients into fresh water first, then use pH Down to fine-tune.

What is pH Down made from?

The liquid formula uses food-grade phosphoric acid.

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