API pH Down Aquarium pH Adjuster - 16 oz | CritterWarehouse.com

API pH Down Aquarium pH Adjuster

by API

Selected Option: 16 oz
$23.99 (You Save 47%)
Free Shipping Over $59
In Stock
Selected Option: 16 oz

Key Features

  • Lowers pH for freshwater aquariums
  • For community aquariums, soft water and live-bearing fish
  • Will not cloud or color aquarium water
  • 1.25 oz.bottle on card (37 ml)
  • 1/2 teaspoonful for each 25 gallons of aquarium water.


API pH Down Aquarium pH Adjuster 16 oz

Aquarium Pharmaceuticals pH Down lowers pH and makes aquariums more acidic. Fast-acting, colorless and easy-to-use. API pH Down is fast acting, colorless, easy to use and will not cloud or color aquarium water.

The colorless formula will not cloud or color aquarium water. Contains no phosphates, a major source of algae outbreaks.

The following pH levels are recommended for freshwater tropical fish:

Egg-laying fish: 6.6 to 6.8 (slightly acidic)

Community aquarium: 7.0 (neutral)

Live bearing fish: 7.2 to 7.6 (slightly alkaline)

Directions For Use: Use API Freshwater pH Test Kit to determine the pH of aquarium water.To lower pH, add two drops of pH Down for each gallon of aquarium water.Take another pH reading before adding the next dose of pH Down.If fish are present in the aquarium, do not change the pH more than 0.2 in any 24 hour period (for example, from 7.2 to 7.0).

In case of contact with eyes, rinse immediately with plenty of water and seek medical attention. If on skin, flush with water for 15 minutes. Remove contaminated clothing. In case of accident or if you feel unwell, seek medical advice immediately (show label where possible). If swallowed, do not induce vomiting. Never add water to this product.

Danger: Causes severe burns. May be fatal if swallowed. Read cautionary information.

Danger Poison: contains Sulfuric Acid (EINECNo. 231-639-5). Causes severe burns.

Keep out of the reach of children.


Brand API
UPC 017163020301
Item Number L-AP030B90910D03-11940
Size 16 oz
Weight 1.2 lbs.
Pkg Dimensions 8.75" (L) x 2.5" (W) x 2.5" (H)

Customer Reviews

   5.0 out of 5
5 star
4 star
3 star
2 star
1 star

Add a Review

Your rating:  
Your email will NOT be published or displayed.

Reviewed by Amy H. on Apr 2, 2021

filters and doing your water changes weekly or bi monthly like your supposed to be

Reviewed by Kathy K. on Mar 21, 2021

Worked over night.

Reviewed by Travis H. on Mar 2, 2021

Works well but heard to measure pH change

Reviewed by Rick Va Y. on Feb 24, 2021

Ph down

Reviewed by Evans Mercier on Dec 19, 2020

Good product

Reviewed by Samir Mourad on Dec 6, 2020

Don’t kill your fish

Reviewed by Colleen Herbst on Nov 17, 2020

I've used the product before and it does work great. Always remember

Reviewed by Emelia Donkor on Oct 12, 2020

Be Careful

Reviewed by Paulette R. on Sep 3, 2020

pH Down works well. You might need a dropper if you have a small tank.

Reviewed by Karen L. on Aug 27, 2020

keeps your Betta fish healthy!

Reviewed by Robert Nothnagle on Jun 11, 2020

Saved my aquarium!

Add a Review

Your rating:  
Your email will NOT be published or displayed.

Join the Critter Club and get exclusive access to coupons and special offers just for club members!

Plus get a $5 off coupon code you can use today!

CritterWarehouse.com Email List Signup
We'll never share your email address with any third-parties.