The store will not work correctly in the case when cookies are disabled.
Bulk Reef Supply Saltwater Logo
Bulk Reef Supply Freshwater Logo

FREE Shipping Over $49

Free Shipping

Orders Over $49 Ship Free

$5.99 economy shipping on orders under $49

Learn More
| Earn Reward Points
Skip to Content
Menu BRS Freshwater
My Cart
    • My Account
    • My Wish List
    • My Orders
    • Address Book
    • Sign Out
    • Reward Points
  • Sign In
Bulk Reef Supply Mobile Menu
Close

Quick Links

  • Deals
  • Gift Cards
  • What's New
  • Education
  • Clearance
  • Open Box
  • PR Rewards
  • Shop Brands
  • FAQs
  • Saltwater
Menu
Weekly Deals Weekly Deals
Sign up to be a Reward Member Earn Reward Points
Returns 365-Day Returns
Experts Aquarium Experts
  • Weekly Deals Weekly Deals
  • Sign up to be a Reward Member Earn Reward Points
  • Returns Risk-Free 365 Day Returns
  • Experts Aquarium Experts
Loading...
Hanna Instruments

Marine Magnesium Colorimeter HI783

In stock
Out of stock
SKU
251158
Be the first to review this product
$67.99 $67.99

- +
Add to Wish List
Risk Free 365 Returns

Your Satisfaction Guaranteed With
365 Day Risk Free Returns

No longer need what you ordered? Ordered one too many? We've got your back.


Return new, unopened products in original packaging within 365 days for a full refund.

Under 60 days? No problem. We’ll issue your refund to the original form of payment. Over 60 days? Still no problem. We'll issue your refund in the form of store credit, which you can use like cash on our website.


Return unused, open box products within 30 days.

Open box but still unused? We can help. We’ll issue your refund to the original form of payment minus a small 10% restocking and handling fee.

Some exclusions apply, for more information go to Return & Replacement Details.

Skip to the end of the images gallery
main product photo
Skip to the beginning of the images gallery
Details

Magnesium is a crucial element in saltwater environments, as it allows calcium and carbonate to be bioavailable for corals and other invertebrates. Therefore, consistent and accurate testing of magnesium levels in your marine aquarium is vital to ensure a healthy and thriving system.

 

The HI783 Magnesium Checker HC by Hanna Instruments provides a simple, accurate, and affordable way to measure magnesium in saltwater/marine environments. Its color-coded syringes and straightforward testing strips ensure quick and hassle-free measurements, every time. With a digital read out, there is no more struggling to determine colors visually. 

  • Ideal for saltwater aquariums, marine biology, and aquaculture applications
  • Easier to use and more accurate than other chemical test kits
  • Color-coded syringes for simple and effortless testing
  • Dedicated to a single parameter
  • Simple one-button operation
  • Large LCD digital read out for added convenience
  • Auto shut-off to assure the battery wont be drained
  • Compact size for easy travel and storage

 

Specifications

  • Range: 1,000 to 1,800 ppm Magnesium
  • Resolution: 5 ppm
  • Precision: ±5% of reading @ 77°F (25°C)
  • Light Source: LED @ 610 nm
  • Light Detector: Silicon photocell
  • Environment: 0 to 50°C (32 to 122°F); max 95% RH non-condensing. Prepared sample cuvette (sample plus reagents) must be 18 to 28 °C (64 to 82 °F).
  • Battery Type: (1) 1.5V AAA
  • Auto-off: After 10 minutes of non-use
  • Dimensions: 86 x 61 x 37.5 mm (3.4 x 2.4 x 1.5")
  • Weight: 64 g (2.3 oz.)
  • Method: Adaptation of the colorimetric EDTA method using calmagite indicator. The reaction between magnesium and the reagents causes a blue to violet tint in the sample.
  • Interferences: Calcium below 300 ppm and above 500 ppm
  • Reagent Set: HI783-25 (25 tests)
  • Calibration Set: HI783-11
  • Warranty: 1 Year

 

What’s Included?

  • (1x) HI783 Marine MagnesiumChecker HC 
  • (1x) Carrying case
  • (1x) Sample cuvette and (2x) caps
  • (1x) Marine Magnesium Starter Kit (reagents for 25 tests)
  • (1x) 1mL graduated syringe and tip
  • (1x) 5mL Syringe and tip with black printing
  • (1x) 5mL Syringe and tip with blue printing
  • (1x) 1.5V AAA Alkaline battery
  • (1x) Instruction manual
  • (1x) Quick reference guide
More Information
More Information
SKU 251158
Instruction Manual Product Manual
Quick Reference Guide
Reviews 18
Write Your Own Review
You're reviewing:Marine Magnesium Colorimeter HI783
Your Rating
Product Questions

Product Questions

Is the new version with the 3 minute countdown and powder packet instead of the liquid?
Question by: Mario on Nov 3, 2022, 9:43 PM
The Hanna Instruments Marine Magnesium Colorimter has been updated with the timer. The reagent kits are liquid https://www.bulkreefsupply.com/hi783-25-marine-magnesium-reagents-25-pack-hanna-instruments.html.
Answer by: Scott F. (BRS Staff) on Nov 9, 2022, 12:26 PM
Is this magnesium checker the new updated version? The one that comes with a 3 minute timer and powder packets that replaced the bad liquid that was used or original
Question by: Mario Lopez on Nov 2, 2022, 9:30 PM
Thanks for the question! The checkers we have are the new updated version at this time. The old ones were returned to Hanna once they made the recall and are not available any longer. Please let us know if we can help with anything else!
Answer by: Kyle Thomas (BRS Staff) on Nov 9, 2022, 11:44 AM

SIGN UP FOR THE BULK REEF SUPPLY NEWSLETTER

Don’t be the last to know this holiday season about sales, specials, new products, and more!

Sign Up Now
BRS Fresh https://media2.cdn.bulkreefsupply.com/media/logo/stores/1/BRS-Logo-498x174.png https://fresh.bulkreefsupply.com/
BRS Fresh Bulk Reef Supply
  • Facebook Opens a new window
  • Youtube Opens a new window
  • Instagram Opens a new window
  • TikTok Opens a new window

Contact

  • 763-432-9691

  • 8am - 6pm CT M-Th
    9am - 4pm CT Friday
  • support@bulkreefsupply.com
  • 6325 Sandburg Road, Suite 200
    Golden Valley, MN 55427 US

Bulk Reef Supply
About Us
Customer Service
Careers
Wholesale Customers
Instructions
Terms & Conditions
Customer Center
Preferred Reefer Program
International Shipping
Returns & Replacements
Payment, Pricing & Promos
Shipping & Delivery
APL Star Logo
© 2025 Aperture Pet & Life. All Rights Reserved.
Privacy Policy

item(s) Added to Your Cart

Product Name

View Cart Checkout Now
You may also like
Robotic Fish STEM Science Set
Bulk Reef Supply
Robotic Fish STEM Science Set
$29.99 $29.99

Bio-Stratum Planted Aquarium Substrate
Fluval
Bio-Stratum Planted Aquarium Substrate
From: $19.99

Choose Options
Dual-Sided Substrate Shovel (12.6 inch)
Fluval
Dual-Sided Substrate Shovel (12.6 inch)
$11.49 $11.49

River Rock/Coral Bliss Aquarium Backgrounds
SeaView
River Rock/Coral Bliss Aquarium Backgrounds
From: $15.99

Choose Options
Betta Tropical Almond Leaves (10-pack)
Fluval
Betta Tropical Almond Leaves (10-pack)
$11.49 $11.49

Aquarium Lab Multi-Test Kit
NT Labs
Aquarium Lab Multi-Test Kit
$46.98 $46.98

Hardness Test Kit
NT Labs
Hardness Test Kit
Rating:
100%
1 Review
$11.42 $11.42

River Rock/Sea of Green Aquarium Backgrounds
SeaView
River Rock/Sea of Green Aquarium Backgrounds
From: $2.10

Choose Options
Betta Fish 1000pc Puzzle
Tactic USA
Betta Fish 1000pc Puzzle
$15.99 $15.99

Sugar White Bio-Substrate (5lbs)
Aqua Natural
Sugar White Bio-Substrate (5lbs)
$12.99 $12.99

Login and Registration Form

  • Login
  • Register

Registered Customers
If you have an account, sign in with your email address.
Forgot Your Password?
or

Login with Your Social Profile Login with
Continue with Google
Continue with Facebook
Continue with Apple

Personal Information
Sign-in Information
Password Strength: No Password
Back
or

Login with Your Social Profile Login with
Continue with Google
Continue with Facebook
Continue with Apple
  • Forgot Your Password?

Please enter your email address below to receive a password reset link.
Go back