pH Down by Growth Technology bottle, 85% phosphoric acid pH reducer for hydroponic solutions

pH Down by Growth Technology — 85% Phosphoric Acid pH Reducer for Hydroponic Solutions

NPH-D.25L

$15.95
/
Tax included. Shipping calculated at checkout.

85% w/v phosphoric acid for lowering nutrient solution pH. Dose drop by drop after the nutrient is mixed, retest, repeat. Gloves and eye protection.

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Pairs well with

When a fresh nutrient mix reads above the range your plants feed best in, it needs bringing down, and slowly. pH Down is Growth Technology's adjuster for lowering the pH of hydroponic nutrient solutions, 85% w/v phosphoric acid, dosed with a dropper and stirred through after the nutrient and additives are in. Growth Technology's method: test, add a few counted drops, stir, retest, and record the drops per litre so the next mix starts from a known number. It is a strong acid. The label carries a Poison S6 schedule, it is a Class 8 corrosive, and gloves and eye protection go on before the cap comes off. Available in 250ml, 1L and 5L.

Dangerous goods: road freight or pickup. pH Down is a Class 8 corrosive and can't travel by standard post. Online orders go by dangerous-goods road courier at a separate freight charge that isn't included in free shipping over $499*, and delivery may take longer. We'll contact you after you order to confirm. Prefer to skip the freight? Choose pickup from our Invermay store or local delivery at checkout.
Dosed by the drop85% w/v phosphoric acid is concentrated, so small counted doses do the work. That is what stops a reservoir lurching past your target.
Phosphate, not chlorideIt lowers pH with phosphoric acid, so what it leaves in the tank is phosphate, a nutrient plants use, rather than chloride or sulfate.
Built for GT nutrientsGrowth Technology's Ionic and GT Coco directions both finish with a test and adjust to pH 5.5–6.5. This is the same maker's tool for that last step.
A method you can repeatRecord the drops per litre each time. The next mix of the same nutrient starts from a known number.
Three sizes250ml suits a tent or a few reservoirs, 1L a bigger system, 5L a grower who mixes by the drum.
Cheaper as a pairThe pH Up & Down Set puts both adjusters together in matching sizes for less than buying them separately.
Read before you buy Poison S6. pH Down is 85% w/v phosphoric acid and a Class 8 corrosive dangerous good (UN 1805). Growth Technology directs you to avoid contact with skin and eyes and to wear protective gloves and eye and face protection when mixing or using it. Store it in a secure, well-ventilated place out of reach of children. First aid: contact the Poisons Information Centre on 13 11 26 or a doctor at once. If swallowed, do not induce vomiting; give a glass of water. Eyes: hold the lids apart and flush with running water for at least 15 minutes, then see a doctor. Skin or hair: remove contaminated clothing and flush with running water.

Specifications
Brand: Growth Technology
Type: pH adjuster, lowers pH
Contains (label): Phosphoric acid 85% w/v
Use: Lowering the pH of hydroponic nutrient solutions
Dose: No fixed rate: add drop by drop, test, repeat
Target pH: 5.5–6.5 for Growth Technology hydroponic and coco nutrients
When to adjust: Last, after nutrients and additives are mixed and settled
Poisons schedule: S6
Dangerous goods: Class 8 corrosive, UN 1805
Protective equipment: Gloves, eye and face protection
Storage: Secure, well-ventilated place, out of reach of children
Delivery: Dangerous-goods road courier at a separate freight charge, store pickup or local delivery
Sizes: 250ml, 1L, 5L

Grower's Tip
  • Calibrate your pH pen before you trust the reading. Every drop you add is only as good as the number you are chasing.
  • Adjust last. Growth Technology's method is nutrients and additives in, mixed and settled, then test and adjust.
  • Running Silica? It is alkaline and lifts the pH, so expect to need more pH Down on those mixes.
  • One drop at a time, stir, retest. Acid this strong overshoots fast.
  • Write down the drops per litre every time. After a couple of mixes you know your starting dose.
  • Never pour pH Down and pH Up into each other or share a dropper or measuring cup between them.
  • Keep the cap on and the bottle locked away. It is a Schedule 6 poison and a corrosive.

How To Use It
1Mix your nutrients and any additives into the reservoir, stir well and let the solution settle.
2Test the pH with a calibrated pen or meter.
3Put on gloves and eye protection. Using a dropper, add a small amount of pH Down, counting the drops, then stir it through.
4Retest. Repeat the last step until the solution reaches your target pH, which is 5.5–6.5 for Growth Technology's hydroponic and coco nutrients.
5Write down how many drops per litre it took. Next time you mix the same nutrient at the same strength, you have a starting point.

Pairs Well With

Frequently Asked Questions
Is pH Down dangerous?

Yes. It is 85% w/v phosphoric acid, a Schedule 6 poison and a Class 8 corrosive. Avoid contact with skin and eyes and wear gloves and eye and face protection whenever you use it.

How much pH Down do I use?

There is no fixed rate. Growth Technology's method is to add a small amount with a dropper, counting the drops, stir, retest and repeat until you hit your target, then record the drops per litre for next time.

What pH should I aim for?

5.5–6.5 for Growth Technology's hydroponic and coco nutrients, which is the range in their Ionic and GT Coco directions.

When should I adjust the pH?

Last. Mix your nutrients and additives, let the solution settle, then test and adjust.

What is in pH Down?

Phosphoric acid at 85% w/v, as printed on the label.

Is this the same as GT pH Drop?

No. pH Drop is a separate Growth Technology product based on citric acid. This pH Down is phosphoric acid.

Can you post pH Down to me?

Not by standard post. It is a dangerous good, so online orders go by dangerous-goods road courier at a separate freight charge, not included in free shipping over $499*. We contact you after you order to confirm. Pickup from our Invermay store and local delivery are also available.

What do I do if it gets on my skin or in my eyes?

Skin: remove contaminated clothing and flush with running water. Eyes: hold the lids apart and flush with running water for at least 15 minutes, then see a doctor. For anything more, call the Poisons Information Centre on 13 11 26.

Which size should I buy?

Dosed by the drop, a 250ml bottle lasts most home setups a long time. The 1L suits bigger systems and the 5L growers who mix by the drum.

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Bring the pH down, a drop at a time

Corrosive, so it travels by dangerous-goods road freight or pickup in Invermay. We'll call to confirm online orders.

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