The Athena Blended CaMg is the calcium, magnesium and iron additive for the Blended Line. It sits alongside Grow A & B or Bloom A & B and tops up the elements demanding cultivars and conditions run short of, without throwing the base formula out of balance. On RO water or in coco and rockwool, it's usually a regular part of the feed.
Why growers add it
Athena's two-part bases already carry calcium and magnesium. But some cultivars, and some conditions, need more during heavy growth — particularly under strong light, through rapid veg, and in the early weeks of flower. CaMg adds calcium, magnesium, iron and nitrogen together, in proportion, so you can lift those elements without skewing the rest of the feed.
RO water and inert media
Reverse osmosis water starts with almost no minerals, and inert media like coco and rockwool supply none of their own. In those setups, calcium and magnesium have to come entirely from the feed — which is where CaMg earns its place. It's also the main tool the Blended Line gives you to raise EC without changing the base ratio.
Full specifications
| Manufacturer | Athena (Los Angeles, USA) |
| Line | Blended Line — variable EC |
| Type | Liquid mineral additive |
| Supplies | Calcium, magnesium, iron and nitrogen |
| Stage | All stages, as needed |
| Dose rate | Approx. 0.66 mL per litre (2.5 mL per US gal) as a starting point — see the Athena metric feed schedule (PDF) |
| Sizes | 0.9 L (32 fl oz) · 3.78 L (1 US gal) · 18.9 L (5 US gal) |
| Best suited to | RO water; inert media such as coco and rockwool; hydro and DWC |
| Storage | Sealed in original bottle, 7–29°C (45–85°F) |
FAQ
Do I need CaMg if my tap water is hard?
Often less, sometimes not at all. Hard water already carries calcium and magnesium. Test your source water, then follow the feed chart and add CaMg only if the plants or your EC readings call for it.
Can I use it in veg and flower?
Yes. It works with both Grow A & B and Bloom A & B across the whole cycle.
Can I use it in DWC?
Yes. It's part of the Blended Line, the Athena line for DWC and RDWC, and it's a standard part of Athena's RDWC procedure.
Do I need it with the Pro Line?
No. On the Pro Line, calcium comes from Pro Line Core. CaMg is designed for the Blended Line.