Brightwell Aquatics

Iodion - Liquid Iodine Supplement

Grouped product items
Iodion - Liquid Iodine Supplement - Long Acting 500ml

SKU: 209249

In stock

$16.28 $16.28

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  • Highly-concentrated, extended activity iodide solution.
  • Provides iodide, which is important to hermatypic corals and other invertebrates harboring zooxanthellae, macroalgae, and also to the health of fishes.
  • Stronger than most competing products.
  • The nature of iodide sources used makes Iodion more effective than standard iodide-solutions.
  • Suitable for use by aquarium hobbyists of all skill and experience levels.
  • Composed of purified water and ultra-high purity materials.
  • Formulated by a marine scientist.


Instructions and Guidelines

Basic: Shake product well before using. Add 5 ml (1 capful) of product per 50 US-gallons of aquarium water every two- to three-days or as needed to maintain the iodine concentration within a range of 0.04 - 0.06 ppm. When used in this fashion, 250 ml treats up to 2,500 US-gallons (9,464 L).


Keep out of reach of children. Not for human consumption. Contact poison control center if ingested.
Guaranteed Analysis

Purified water, Potassium iodide, Stabilized iodide

All Brightwell Aquatics liquid water care supplements are made with purified water and high purity materials. Brightwell has developed formulas for aquaria based on empirical data, using observation and measurement rather than theory.

Technical Background

Presence of iodine is vital to hermatypic invertebrates because it is used to detoxify excess oxygen produced by zooxanthellae. This oxygen irritates sensitive tissue. Corals and clams that appear to shrivel or close under intense lighting are likely attempting to shade their zooxanthellae symbionts to reduce the rate of oxygen production. Iodide essentially bonds with oxygen to form non-toxic iodate, relieving the need to shield zooxanthellae and enabling the host organism to open more fully.

The predominant form of iodine in seawater is iodide. The natural seawater concentration of all iodine species combined is approximately 0.06 ppm, classifying it as a minor element. Even in this small concentration, iodine is required for survival of fishes, crustaceans, macroalgae and kelp, and hermatypic invertebrates alike. The importance of iodine in a reef aquarium cannot be overstated. Iodine binds rapidly with latent organic material and is passively removed by aggressive protein skimming and the use of organic-adsorption products such as activated carbon and specialty resins. The combined biological and chemical depletion of iodine necessitate that its concentration be monitored and the aquarium supplemented as needed. The rate at which iodine is extracted from the water is determined by the stocking density of reef-building livestock, type of lighting, and other biological, physical, and chemical conditions. Once the rate of iodine uptake in the aquarium has been determined, the proper dosing rate of this product can be easily calculated.

More Information
Additive Type Iodine
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Product Questions

What is the difference between this product and lugols iodine?
Question by: Logan Williams on Dec 15, 2021, 10:58 AM
The main difference between Iodion and Lugol's solution is the concentration Lugol's has a much higher concentration.
Answer by: William Glenn (BRS Staff) on Dec 16, 2021, 1:35 PM
How much will 5 mL of this supplement increase the iodine level in 10 gallons of water?
Question by: Kraig Roupe on Jan 7, 2019, 4:44 PM
Thank you for reaching out to Bulk Reef Supply! It requires extra precaution when dosing anything into a nano aquarium especially if it is something new to your tank. The recommended dosing for this particular product is 5ml/50 gallons of water so the proper dose for a 10 gallon would be 1ml. Overdosing can be very harmful if not fetal to reef inhabitants. A common rule of thumb when starting to dose something new is to dose half the recommended amount and increase slowly as needed. I hope this was helpful. Please reach back out if you have any further questions!
Answer by: Ashley on Jan 7, 2019, 6:07 PM