pH Down - 7lbs

Regular price $39.99
Sale price $39.99 Regular price
Sale Sold out
Unit price
Shipping calculated at checkout.
This is a pre order item. We will ship it when it comes in stock.

Why use pH-

The pH- reduces the basicity of your swimming pool water. A good pH level helps to decrease corrosion, optimizes the effectiveness of disinfection products, and makes the water less aggressive for the skin and the eyes.

iopool pH- is the perfect product to maintain your pool and hot tub water to the optimal levels for crystal clear water. This product is designed to be easy to use and quick to react, allowing for quick and easy pH adjustments. The iopool pH- is reliable and safe.

Use it with app

You can free download our application on Apple Store (IOS) or Play Store (Android). Then you can follow advice from our recommendation engine to know when and how you can use our chemicals products.

Main advantages

  • High pH- concentration;
  • High pH- grade quality;
  • Ease of dissolution;
  • Speed of action;
  • Treatment efficiency;
  • A small amount of dust.
  • Compatible with all treatments.
  • Compatible with all filtration systems.

How it works

The pH indicates a concentration of hydrogen ions. High pH is poor in hydrogen ions. By being released into the water of your swimming pool, the pH + of iopool increase the concentration of hydrogen ions and decreases the basicity of your pH.


Related blog articles

Find helpful tips, tricks, and information about pH on our blog.

Usage advice

  • Activate the filtration of your swimming pool;
  • Dilute the pH- in a bucket of water;
  • Disperse the mixture of water and pH- in your swimming pool.


  • Stabilize your pH before any disinfection treatment (chlorine and active oxygen);
  • pH modifiers are corrosive products that must be handled with precaution and do not spill on natural stones, clothing, and bare skin;
  • In case of very acidic water, correct it over several days.


    Customer Reviews

    Based on 5 reviews
    Troy Humphries
    I wish it measured more….

    It does really good at sending measurements of Ph and Sanitizer, once you get it all set-up. Which took me a little bit to do, due to the strength of my internet outside. I wish it would also test alkalinity & hardness of my water. Basically I wish it always measured and sent you data on everything that you use a teat strip for.

    Ricardo Shiroma
    Works well with iopool, but pricey

    I liked the fact iopool provide the simple and precise measurement to be add to the pool, but the product is pricey. As 8/4/2023, the price is about $5.72 per pound but you can find similar Sodium Bisulfate for $1.60 per pound at Walmart or Amazon.

    Kenneth Gardner

    It is expensive and doesn't last very long after lowering the PH.

    Good quality

    Good quality

    Fast shipping

    The lads deliver in less than 4 days all accross the US :o