SKU: 302160087

Sera Magnesium-Test (Mg)-Reagent 3 Refill Pack-3x15ml [Volume - 45ml]

Sale price$81.00 Regular price$90.00
Save 10%

Pay in installments of $22.50 with ShopPay, AfterPay and Klarna

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 19 - Jul 24

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

Sera Magnesium-Test (Mg)-Reagent 3 Refill Pack-3x15ml [Volume - 45ml]This product is designed to measure the concentration of magnesium in a marine aquarium and includes a spare cartridge for reagent 3. Warning! Reagent 1 contains sodium hydroxide, which can cause serious burns. Keep this reagent securely stored and out of reach of children. Always wear protective gloves when handling. If the substance comes into contact with your eyes, rinse immediately with water and seek medical attention. If you experience nausea,

This product is designed to measure the concentration of magnesium in a marine aquarium and includes a spare cartridge for reagent 3.

Warning! Reagent 1 contains sodium hydroxide, which can cause serious burns. Keep this reagent securely stored and out of reach of children. Always wear protective gloves when handling. If the substance comes into contact with your eyes, rinse immediately with water and seek medical attention. If you experience nausea, consult a doctor and bring this manual with you.

A proper magnesium concentration is essential for the health of marine invertebrates and algae. A prime example is the red calcareous algae, which require substantial amounts of magnesium to form their skeletons. Natural seawater typically has around 1300 mg/l of magnesium. To create optimal conditions in your marine aquarium, it's crucial to maintain this concentration. The Sera magnesium test allows you to quickly and easily assess the magnesium level in your aquarium. You can also effectively boost magnesium levels using Sera magnesium plus.

Additionally, magnesium levels can be raised with Sera marin COMPONENT 6 magnesium. The amount of reagent needed will depend on the calcium levels in the water you are testing.

Store in a cool, dark place!

Instructions for Use:

In a marine water aquarium, maintaining an optimal magnesium level is vital for the thriving of invertebrates and decorative algae. Red calcareous algae are a great example, as they require high magnesium levels for their skeletal structure. Natural marine water contains around 1,300 mg/l, which should also be replicated in your aquarium for ideal conditions. The Sera magnesium-Test enables you to monitor your aquarium’s magnesium levels swiftly and efficiently. If you have prior testing experience with the Sera calcium-Test, this will be even easier for you. You can easily enhance the magnesium level in your marine water aquarium by using Sera marin COMPONENT 6 magnesium.

Directions for use: Shake the reagent bottles well before use! Avoid letting the tested water come into contact with aquarium or pond water!

  1. Rinse the measurement vial several times with the water you wish to test, then empty it. Dry the outside of the vial.
  2. Rinse the syringe multiple times with the water to be tested, then use it to fill the vial with 2 ml of this water.
  3. Add 6 drops of reagent 1 and shake the vial until the liquid is evenly mixed. Any cloudiness that appears will not affect the test.
  4. Add one level measuring spoon (provided in the kit) of reagent 2 to the vial and gently swirl (do not shake) until the powder has dissolved.
  5. Gradually add reagent 3 drop by drop while counting them. After every 5 drops, release pressure on the bottle to allow air to enter. Shake the vial after each drop until the color shifts from pink to blue (not violet) and remains stable for at least 30 seconds while you gently whirl the vial occasionally. Note the number of drops used.
  6. Empty and thoroughly rinse the measurement vial with tap water, then rinse it several times with the water to be tested and empty it again. Dry the outside of the vial.
  7. Use the syringe to take up 2 ml of the water to be tested and fill the vial.
  8. Add 6 drops of reagent 4 and shake the vial until the liquid is evenly mixed. Any cloudiness that appears will not affect the test.
  9. Add one level measuring spoon (included in the kit) of reagent 5 to the vial and gently swirl (do not shake) until the powder has dissolved.
  10. Add reagent 3 drop by drop while counting the drops, releasing pressure on the bottle after every 5 drops to allow air to be drawn in. Shake the vial after each drop until the color changes from red to green and remains stable for at least 30 seconds while whirling the vial occasionally. Note – you will require significantly more drops for this measurement compared to the first measurement!
  11. To find the magnesium level, subtract the number of drops used for the first measurement from the number of drops used for the second measurement. Multiply the remaining number of drops by 60 to calculate the magnesium level in mg/l. For example, if the first measurement used 4 drops and the second used 24 drops, subtracting gives you 20 drops. Multiplying 20 drops by 60 results in a magnesium level of 1,200 mg/l.
  12. Cleaning: Thoroughly clean the vial and syringe with tap water before and after each test. Close the reagent bottles immediately after use and do not switch caps. Store at room temperature and away from light. This product is intended for testing ornamental fish aquariums and pond water only.

Store in a cool, dark place!

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 302160087

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.6 ★★★★★
Based on 19 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
B
BobbyG
Belleville, US
★★★★★ 4
Expensive, but Smooth, Sturdy Spice Rack
I received the BOIVSHI Spice Rack Organizer through the Vine program, and overall I’m quite pleased with its quality. The rack feels sturdy and well-made. The metal construction has a solid, heavy-duty feel, and the chrome finish gives it a clean, modern look that works well in most kitchens. The pull-out mechanism is smooth and glides nicely. The 2-tier design is efficient and makes good use of vertical space. Installation was fairly easy and the instructions are simple enough to follow. For me, it is limited to smaller spice bottles, due to the configuration of my cabinet which limits the available height of the top tier. Also, the rack has to be secured to the surface, either with screws or adhesive mount, to prevent it from sliding around. Overall, it is well made and a practical solution for organizing spices. If your cabinet dimensions are compatible and you mostly use standard-size spice jars, it’s a solid upgrade that makes everyday cooking more convenient. However, this is a very expensive spice rack, if you compare it to similar items.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 6, 2026
A
Amazon Customer
Louisville, US
★★★★★ 5
Good size, looks nice, mostly easy to put together and install
Okay I love this a lot more than I expected to. I was not extremely excited about the instructions. They come with a warning that if you have any doubts about your ability to install this, call a qualified technician. It just seemed condescending. Also, everything is printed poorly, like someone put this together in the 80's and it printed smudgingly and this is the copies from that. The only thing that this made confusing was when trying to figure out where the cabinet screws go (before I realized that was an alternative install), you really can't tell which holes they go in. Turns out they probably go in the holes covered by the pre-installed sticky PVC mat. Only other issue I had was that it comes with a screwdriver. It seems so wasteful to include something that should be in every household, especially those who buy diy things like this. But beyond that, everything else is great. It was easy to put together, it was easy to place in the cupboard, and it was easy to fill. I love that each line comes out individually. It's nice and sturdy. I tried pulling on it to test it, and the sticky was strong. I mostly loved that, even though this took up 3/4 of the shelf, I was able to fit all my small spices AND my honey AND my sprinkles. I went from 3 overflowing shelves to 2 full shelves and an almost empty one. I only have 6 items on the top. I feel super happy about this.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 5, 2026
A
Verified Purchase
Amy
Houston, US
★★★★★ 5
Great product! :)
Color: 01-silver
It looks great and work very smoothly on our kitchen counter.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 30, 2026
T
Verified Purchase
Thomas J Standeven
Fort Morgan, US
★★★★★ 5
Very fuctional
Color: 01-silver
Very stylish and functional, the suction cups hold it in place
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 25, 2026
J
Verified Purchase
Jacki Torres
Fort Morgan, US
★★★★★ 4
Functional and Good Quality
Color: 01-silver, Color: 01-silver
I give this SMARTAKE paper towel holder 4 stars. Overall, it's a very good product that I would recommend, but it has one minor drawback that takes away a star. The Positives Quality and Stability: The holder feels good quality, and the material (steel) is sturdy. Once placed on the counter, it's stable and adheres well to the surface. Assembly and Use: It was easy to put together; just read the instruction manual. I confirm that it works well even with large paper towel rolls. Furthermore, it's not difficult to change the roll at all. The Drawback The only problem is the small mechanism that's supposed to adjust and hold the roll (the piece that prevents it from twisting too much). As the paper gets used up, this piece doesn't do its job properly, and the paper unwinds more than it should. Conclusion: If you're looking for a modern, stable, and well-made holder for your kitchen, this is excellent. Just keep in mind that the adjuster isn't the best, but other than that, it does its job perfectly.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on October 18, 2025

recommand products