Tropic Marin Bio Calcium Supplement 18oz
Biologically ideal magnesium supplement for reef aquariums. Some corals and coralline algae use magnesium, in addition to calcium and strontium, in the formation of skeleton structure. The addition of BIO-MAGNESIUM to the marine aquarium restores the crucial magnesium/calcium ratio to its natural seawater concentrations, ensuring optimal skeletal growth.
| Specification | Value |
|---|---|
| Product Type | Calcium and Magnesium Supplement |
| Volume | 18 oz (536 ml) |
| Brand | Tropic Marin Usa Inc |
| Royal Item Number | ATM29432 |
FAQ
What is the role of magnesium in a reef aquarium?
Magnesium plays a crucial role in the formation of coral and coralline algae skeletons. It works with calcium and strontium to maintain the proper skeletal structure and supports optimal growth in reef environments.
Is this product suitable for all types of reef tanks?
Yes, this supplement is specifically formulated for reef aquariums and supports the biological needs of corals and coralline algae that require magnesium for skeletal development.
How does this product maintain the magnesium/calcium ratio?
The supplement restores the magnesium/calcium ratio to natural seawater concentrations, ensuring balanced conditions for coral growth and skeletal health.

Karen Mathis –
I’ve used this supplement for six months in my 50-gallon reef tank. My corals have grown more robustly, and the water parameters have stayed stable. The product dissolves easily and doesn’t cloud the water. Great for maintaining proper magnesium levels.
Warren Gill –
It’s a reliable source of magnesium. I mix it with my calcium supplement regularly. My anemones have shown better coloration and stability since I started using it. Easy to measure and store.
Mary Slater –
The magnesium levels in my tank have improved noticeably. I can see better coral growth and less tissue shedding. The 18oz size is sufficient for a medium to large reef tank over several months.