The GreenPlanet Horti Cal 14-0-0 is the calcium base of GreenPlanet's HORTI commercial line. A clean, fully soluble dry fertiliser supplying fast-acting nitrogen plus calcium and magnesium, it runs alongside Horti Grow in veg and Horti Bloom in flower.
The calcium half of HORTI
Calcium can't share a concentrate with the phosphates and sulfates in Horti Grow and Horti Bloom without reacting, so the HORTI line keeps it separate. Horti Cal supplies nitrogen for growth and calcium and magnesium for cell walls and photosynthesis, helping prevent problems like tip burn and leaf yellowing.
How to use it
Mix thoroughly in clean water — add it before other nutrients, keep the solution moving, and check pH. Pair with Horti Grow in veg and Horti Bloom in flower, then switch to Horti Late Cal for the finish. Rates are on the HORTI AU feed chart (PDF).
Full specifications
| Manufacturer | GreenPlanet Nutrients (British Columbia, Canada) |
| Line | HORTI commercial line |
| Type | Dry, fully soluble fertiliser |
| N-P-K | 14-0-0, plus calcium and magnesium |
| Stage | Veg and bloom — replaced by Horti Late Cal for the finish |
| Mixing | Add before other nutrients; keep the solution moving |
| Feed chart | HORTI AU feed chart (PDF) |
| Size | 2.3 kg bag |
| Compatibility | Injectors and drip systems; hydro, coco and soil |
FAQ
Can I mix it with Horti Grow in one tank?
Not as a concentrate — keep HORTI concentrates in separate stock tanks to avoid precipitation. Diluted in the reservoir is fine.
Do I need Pro Cal as well?
No. Horti Cal is the HORTI line's calcium source. Pro Cal is designed for the liquid programs.
Why does it stop at the end of flower?
It contains nitrogen. For the final phase, HORTI swaps to Horti Late Cal, which is nitrogen-free.