Strontium
Strontium is a minor element found in natural seawater that plays a supporting role in coral skeletal formation, incorporating into the aragonite structure alongside calcium during the calcification process. While present at meaningfully lower concentrations than major elements like calcium and magnesium, strontium’s structural role in skeletal formation has made it one of the more commonly supplemented minor elements among reef keepers pursuing comprehensive dosing routines.
Most moderately stocked reef tanks maintain adequate strontium levels through routine water changes with a quality salt mix, with dedicated supplementation more common in heavily stocked, fast-growing SPS-dominant systems.
Why It’s Important
- Incorporates into coral skeletal structure alongside calcium during calcification.
- Present at meaningful, though comparatively modest, natural concentrations.
- One of the more commonly supplemented minor elements in advanced dosing.
- Particularly relevant for heavily stocked, fast-growing SPS-dominant systems.
How It Works
During calcification, strontium ions can substitute partially for calcium within the growing aragonite skeleton, becoming a structural component of coral growth rather than simply a dissolved trace presence. Because this incorporation happens continuously alongside calcium uptake, fast-growing corals consume strontium at a rate that can outpace passive replenishment in heavily stocked systems.
Most reef tanks receive adequate strontium passively through routine water changes with a quality salt mix, though some reef keepers running demanding SPS systems supplement it directly, often through a dedicated strontium and molybdenum product or as part of a broader minor element blend.
Strontium and Related Parameters
Strontium is closely tied to calcium and calcification, the major element and process it supports structurally, and to minor elements as a broader category alongside potassium and boron. It’s also relevant to ICP testing, a useful way to confirm whether strontium levels are tracking naturally or beginning to drift in a heavily stocked system.
Reef keepers running heavily stocked SPS systems sometimes expand their supplementation routine to include strontium once major parameter dosing is well established, using ICP testing results to guide whether targeted dosing is genuinely warranted.
Strontium deficiency symptoms, when they occur, tend to be nonspecific and easily mistaken for other issues, making ICP testing considerably more reliable than attempting to identify a deficiency through visual observation alone.
Because strontium interacts with calcium during skeletal formation, some reef keepers track the two together through periodic ICP testing rather than treating strontium as an entirely isolated parameter.
Reef keepers considering strontium supplementation are generally better served starting with ICP testing to confirm an actual need rather than dosing preemptively without any supporting data.
Common Misconception
A common misconception is that strontium requires the same dosing attention as major elements like calcium or magnesium. In reality, most reef tanks meet strontium needs adequately through routine water changes alone, with direct supplementation genuinely necessary only in more demanding, heavily stocked systems.
The Bottom Line
Strontium is a minor element that incorporates into coral skeletal structure alongside calcium during calcification. Most tanks meet strontium needs through routine water changes, with targeted dosing reserved for heavily stocked, fast-growing SPS setups.
