Made for reef keepers
Every product starts with a clear aquarium purpose, so you can quickly see where it fits in your reef-care routine.
Australian reef aquarium supplies
Simpler reef care.
Clearly supplied.
KNOWN MATTER makes practical reef-maintenance products easier to understand, prepare and use, with clear directions from the start.
- Made for
- Reef aquariums
- Format
- 300 g dry refill
- Availability
- Currently out of stock
PRODUCTKM–001
REEF-FOCUSED
PRACTICAL REFILLS
CLEAR DIRECTIONS
Our standard
Reef care should feel straightforward.
You should be able to understand what a product is for, what you receive and how to use it safely. Known Matter keeps those details clear from the product page through to the bottle.
Packed practically
Useful dry refills keep parcels lighter, reduce leakage risk and let you prepare the product when needed.
Clear directions
Preparation, handling and product support are easy to find and written for hobbyists, not laboratories.
Product · KM–001
Reef Calcium Refill
For reef aquarium calcium maintenance
Made forReef aquarium calcium maintenance
FormatDry calcium refill
IngredientCalcium chloride dihydrate
Net contents300 g
Pack format500 mL preparation bottle
Price$24.95
Standard delivery$12.95
Out of stock
Product details$24.95 · Dispatch in 1–2 business days when stock arrives
A more practical format
A practical calcium refill, ready when your reef needs it.
Receive it dry
The sealed preparation bottle contains a measured 300 g dry refill.
Review the directions
Read the preparation and safety directions supplied with your refill.
Prepare when needed
Prepare the solution as directed, let it cool fully and dose according to your aquarium test results.
The bottle becomes hot while the refill is mixed with water.
Follow the supplied preparation directions, allow the solution to cool completely and read the safety information before use.
Straight answers
Before the bottle reaches your door.
What is the Reef Calcium Refill for?
It is a dry refill for preparing a calcium solution used as part of regular reef aquarium maintenance. Always follow the supplied directions and never add the dry refill directly to your aquarium.
Is this a ready-to-dose liquid?
No. The bottle contains 300 g of dry refill. The 500 mL figure is the bottle capacity, not the amount of ready-made liquid supplied.
Why is it supplied dry?
Supplying it dry avoids shipping unnecessary water, reduces leakage risk and lets you prepare a fresh calcium solution when you need it.
How much should I use in my reef tank?
The prepared bottle contains approximately 160 mg of calcium per mL. Test first, use the dosing table on the product page, make changes gradually and retest because every reef system consumes calcium at a different rate.
First-batch notifications
Know when stock arrives.
The launch price is $24.95 plus $12.95 standard delivery. Email us to request a notification when physical stock is ready and checkout opens.
Request a stock notification