Great Aquariums Start Here
1-800-566-3474
    Free Shipping On $175+
  • FREE Shipping On $175+
  • 14-Day Low Price Guarantee
  • 14-Day Low Price Guarantee
  • Same Day Shipping
  • Same Day Shipping
FREE Shipping on Orders Over $175
FREE Shipping on
Orders Over $175
Standard ground shipping (1-7 business days) starts at a low $5.99 and most orders over $175 ship FREE. Learn More
14-Day Low Price Guarantee
If you find a product we sell for a lower price at another online store, we will match their price—today and up to 14 days after you've purchased the item! Learn More
Same Day Shipping
Same Day Shipping
We promise to ship your order as fast as humanly possible. In fact, 99% of orders placed before 6 pm EST ship the same day! Learn More
Show: per page
Grid View Grid List View List
Sort by:
HM Digital Dual Inline TDS Meter

HM Digital Dual Inline TDS Meter

The Dual TDS meter offers an easy and convenient way of monitoring the performance of your RO or RO/DI unit. It allows you to quickly check the quality of the inlet and outlet water and helps you to determine when the cartridges n...

$29.99
HM Digital Handheld TDS Meter w/ Thermometer

HM Digital Handheld TDS Meter w/ Thermometer

Handheld TDS Meter 0-9990 with ATC & Temp, in vinyl carrying case The world’s most popular TDS meter, the TDS-3 is the most reliable and longest lasting meter of its kind. It has a wide range of 0-9990 ppm has a hold button...

$24.99
HM Digital Pocket-Sized TDS Meter w/ Thermometer

HM Digital Pocket-Sized TDS Meter w/ Thermometer

Pocket Sized TDS Meter w/ digital thermometer in aquarium-specific packaging. The world’s smallest and lightest TDS meter also comes with a built-in digital thermometer. It is a true pocket size meter, comfortably fitting into...

$22.49
TDS Calibration Solution

TDS Calibration Solution

Calibration Fluid for TDS meter with automatic temperature compensation. **Variations of this product can be found in many online stores. The version we carry is of the highest quality. Although this item is eligible for p...

$1.99
HM Digital Triple Inline TDS Monitor

HM Digital Triple Inline TDS Monitor

The TRM-1 is a three-sensor TDS monitor that can monitor the TDS levels at three different points. It is perfect for RO/DI systems and other types of filtration and purification systems. Features Displays TDS levels of the t...

$44.99
HM Digital Waterproof pH Meter

HM Digital Waterproof pH Meter

Professional Waterproof pH/Temp Meter Very reliable waterproof pH meter measures with an accuracy: of +/- 0.02 pH. Measures pH and Temperature Auto-ranging three point calibration with digital fine tuning Includes 4...

$79.99
This item is temporarily unavailable but will be back in stock soon.

Item #
Price:
Click the Add To Cart button below if you'd like to reserve this item today. Any other items included in your order will be immediately processed and shipped. We will ship this item separately as soon as it arrives. We will not charge you for this item until it ships and you will incur no additional shipping charges.

Enter your email address in the field below and click the Notify Me button if you'd like us to send you an email when this item becomes available. Although you will be immediately notified when we have stock on hand, we will not reserve any units for you; you must return to our website and place an order.

Your Email:
Just enter your email address below and we'll let you
know when the product you are looking for becomes available!

Item Code:
Price:
Your Email:
Marine Depot Newsletter Signup
Aquariums, News & Culture
Join 100,000+ readers who receive weekly tips, videos, deals and giveaways.