Ensure your aquarium magnesium levels are just right for your corals with this easy to use and accurate test kit, giving you reliable results that can effect the health of your coral reef.

How to Use

1. Add 2 ml of aquarium water to the test vial with the 2 ml syringe.
2. Add 6 drops of Mg-1 and swirl gently for 30 seconds.
3. Add 1 spoon of Mg-2 powder and swirl for 10 seconds.
4. Fit the plastic tip firmly on the 1 ml syringe and draw up Mg-3 to the 1.00 ml mark, keeping the tip submerged so you draw liquid rather than air. An air layer between the liquid and the piston is normal.
5. Add Mg-3 drop by drop, swirling for a second or two after each drop, until the colour turns grey or blue — whichever you see first.
6. Hold the syringe tip upward and read the upper end of the black piston. Magnesium in ppm = (1 − reading) x 1500, or read it off the table.

Natural sea water runs approximately 1300 to 1500 ppm magnesium, varying with salinity. Magnesium that is too low makes calcium and alkalinity very hard to hold steady, which is usually why a reef tank will not stay in range.

What’s in the Box

Mg-1 and Mg-3 liquid reagents, Mg-2 powder with its spoon, 1 ml and 2 ml syringes, a plastic tip, a test vial, the magnesium reading table and the instructions.

Tests per Kit

Approximately 50 tests, reading in 30 mg/l steps. Marine water only.

Calcium and strontium do not interfere while their combined concentration is between 300 and 500 ppm, which is normally the case in a marine tank. Reagents from older versions of this kit, which used a 3 ml sample, cannot be used with the current version.

Freshness & Storage

Every batch we dispatch carries a minimum of 6 months’ remaining shelf life. Store this product in a cool, dry place away from direct sunlight, with the cap or inner foil closed tightly after each use.

Backorder & Dispatch Timeline

This item is stocked to order. Back-orders are consolidated and placed with our overseas suppliers once a month, on the last day of the month, and all such orders are shipped before the 15th of the following month.

Back-orders cannot be cancelled once they have been placed with the supplier. If you cancel before that, payment-gateway charges of 2% plus GST are deducted and the balance refunded. In the rare case a supplier cannot fulfil the item, we will offer you an alternative first, and refund in full with no deduction if you would rather not take it.

Returns & Replacement

Returns are accepted within 7 days of delivery, provided the item is unused and in its original packaging. Manufacturer-sealed items cannot be returned once the seal is broken, and sale-priced items are not refundable.

If your item arrives defective or damaged, message us on WhatsApp with your order number, or email us if you would rather, and we will replace it. Approved replacements are delivered within 3 to 5 business days. Transit damage is covered by insurance on every shipment. If tracking shows delivered but nothing reached you, tell us within 72 hours, which is the reporting window Indian couriers allow. Damage caused during installation or use is not covered; replacement spares for such cases are chargeable.

Full terms are on our Cancellation & Returns page.