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Two Little Fishies ReMag Magnesium Media - 1 kg

Two Little Fishies ReMag Magnesium Media - 1 kg


Item #: TL40224

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TwoLittleFishies ReMag is their new magnesium-rich media for use in calcium reactors. Use ReMag with ReBorn at a ratio of 1 part ReMag to 9 parts ReBorn to maintain the calcium, magnesium, and alkalinity levels in your reef aquarium water.

ReMag is composed of extremely pure and soluble granules rich in magnesium carbonate. When used in a calcium reactor, ReMag gradually replenishes magnesium and carbonate alkalinity, perfect for maintaining the magnesium concentration and alkalinity in a reef aquarium.

Rinse ReMag briefly in tap water. Add ReMag to a calcium reactor at a ratio of 10% ReMag by volume to 90% ReBorn (or other aragonite media for calcium reactors) to replenish the calcium, magnesium, strontium and carbonate alkalinity that corals and coralline algae utilize to form their skeletons. Used as directed, ReMag easily maintains the ideal magnesium concentration of 1280 - 1300 mg/l in marine aquariums at a salinity of 1.025 - 1.026. If the magnesium concentration is lower than ideal, increase it first by using Two Little Fishies Magnesium Concentrate or Magnesium Pronto. After achieving a level of about 1300 mg/l, use ReMag in a calcium reactor to maintain the concentration. The coarse size of ReMag (5 - 10 mm) allows for unrestricted water flow and easy diffusion of carbon dioxide, for maximum efficiency and easy maintenance of the reactor. ReMag is soluble at a pH of 6.5. Even at typical aquarium pH values it is slightly soluble, so ReMag can be used in a sandbed to help maintain the magnesium level in the water. ReMag does not add chloride or sulfate ions that disturb the ionic balance of the water. Top off the reactor with more ReMag as needed. If ReMag does not maintain the magnesium concentration, do not reduce the pH inside the calcium reactor. Simply increase the ratio of ReMag:Reborn, but do not exceed 25% ReMag by volume as it could raise the alkalinity too high.

Contents: calcium magnesium carbonate

Manufacturer information

Two Little Fishies
Two Little Fishies, Inc. was founded in 1991 to promote the reef aquarium hobby with its introductory video and books about reef aquariums. The company now publishes and distributes the most popular reef aquarium reference books and identification guides in English, German French and Italian, under the d.b.a. Ricordea Publishing.

5 Stars


Reviewed on
October 06, 2019

Yes, I would recommend this.

Keeps my magnesium steady

Pros: Cheaper than other magnesium, easy to use, keeps the mag levels steady.

Cons: None

Since adding this to my calcium reactor at about a 1:9 ratio, I have not needed to adjust my magnesium at all. It’s holding steady.

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Reviewed on
March 01, 2019

Yes, I would recommend this.

Great Supplement for any CaRx

Pros: Great supplement to any CaRx

Cons: Dissolves at a different rate than their Reborn meida

Great product for any CaRx to help supplement Mg. Most if not all CaRx media does not add Magnesium so this is a great supplement.

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jon wardecker

Reviewed on
June 23, 2016

Yes, I would recommend this.

Awesome product

I have run a calcium reactor for years using reborn from two little fishies. When I saw this I figured why not try it and not have to dose mag anymore. I checked my mag for about a month after starting remag and it has stayed the same. No fluctuations at all a steady 1400. It didn't arrive all crushed and powdery and it's a nice course media. I would strongly recommend ReMag if your running a calcium reactor. You already have the reactor so why not. No more dosing for me. Try it! You won't be disappointed

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