Brightwell Magnesion Liquid Magnesium 8.5 oz. (250 ml)
Provides zooplankton and fully-digestible, unhatched eggs ranging in size from 50 to 300 micrometers. Ideal for stony corals, clams, sponges, tunicates, tube worms, larval crustaceans, juvenile fishes, and adult planktivorous and microinvertebrate-predatory fishes.
Formulated to deliver over four thousand prey per milliliter. Does not require refrigeration. Contains a proprietary amino acid to support improved coloration in invertebrates and fish.
Developed by a marine scientist for optimal marine ecosystem support.
| Specification | Value |
|---|---|
| Volume | 8.5 oz (250 ml) |
| Prey Density | Over 4,000 prey per ml |
| Form | Liquid |
| Storage | Room temperature, no refrigeration required |
| Key Additive | Proprietary amino acid for coloration support |
FAQ
How long does the liquid magnesium last once opened?
The product does not require refrigeration and can be stored at room temperature. Shelf life after opening is not specified in the product documentation.
Is the magnesium suitable for all types of marine invertebrates?
It is specifically formulated for stony corals, clams, sponges, tunicates, tube worms, larval crustaceans, juvenile fishes, and adult planktivorous and microinvertebrate-predatory fishes. It may not be suitable for all species.
Can this product be used in reef tanks with live rock?
Yes, it is designed for use in marine aquariums with live rock and is compatible with reef environments.

Connor Murray –
Used this in my 100-gallon reef tank for three months. The zooplankton production is consistent and my corals have shown better coloration. Easy to dose and no issues with storage. Highly recommended for active reef keepers.
Andrew James –
Good source of small prey for my juvenile fish and tube worms. The amino acid seems to help with fish color. I mix it with my weekly feeding routine and notice a steady supply of food.
Grace James –
The liquid form is convenient and doesn’t need refrigeration. I’ve used it for several months and my sponges and tunicates are thriving. The prey size range matches what my corals prefer.
Jason Cameron –
It works well for some species, but I didn’t see much impact on my larger corals. The coloration improvement in fish is noticeable, though. May need to adjust dosage based on tank size.