kH & pH increase significantly dropped Strontium along Calcium

[thejacgues]

Hey there,

I've recently increased my tank pH and kH by using Soda Ash.
I've noticed a significant drop in Calcium (from 500ppm to 155ppm). I understand that it's due to precipitation, but I don't fully understand why Strontium has dropped too... Despite being dosed, it went down to 2ppm while it should be above 6ppm.

I tested it with Aquaforest drip tests and I did ICP to double check, so the results seem fair. Corals stop growing and Styllophora Milka has partially bleached, meanwhile the rest of the colony got very bright and lost 70% of it's color (points with higher PAR got whiter that shadowed elements).

Is it normal?

 

[thejacgues]

I dont know if it matters, but Zinc was significantly elevated, as well as PO4, meanwhile Sulfur was slightly deficient. The rest was fine.

 

[Randy Holmes-Farley]

Strontium looks chemically similar to calcium and gets incorporated by accident into all calcium carbonate formed in the tank, whether abiotic precipitation or coral skeletons. Thus, any increase in calcium and alk consumption by calcification will also increase strontium consumption.

IMO, many folks have misinterpreted this accidental incorporation to indicate that corals need strontium, but I do not think dosing strontium is useful.

 

[thejacgues]

Thank you @Randy Holmes-Farley , that's what I also found on Wikipedia - the chemical similarity of Ca and Sr molecules, which seemed to fit. Thank you for confirming it. Nonetheless, I've also found info that doctors recommend using strontium in case of osteroporosis to increase density and strenghth of human bones - and allegedly the same happens to corals skeletons, depleted strontium weakens them or even a few claim that deficiency may decrease their growth rate. It's hard for me to backup the second assumption / observation, but

Osteoporosis is a chronic disease characterized by low bone mass caused by increased bone turnover and impaired bone microarchitecture. In treatment, we use antiresorptive or anabolic drugs, which usually have a unidirectional effect, i.e., they inhibit the activity of osteoclasts or stimulate the effect of osteoblasts. Strontium ranelate is an anti-osteoporosis drug with a unique mechanism of action (used primarily in postmenopausal women). Unlike other medicines, it has a multidirectional effect on bone tissue, intensifying osteoblastogenesis while inhibiting osteoclastogenesis. It turns out that this effect is demonstrated by strontium ions, an element showing physical and chemical similarity to calcium, the basic element that builds the mineral fraction of bone. As a result, strontium acts through the calcium-sensing receptor (CaSR) receptor in bone tissue cells. In recent years, there has been a significant increase in interest in the introduction of strontium ions in place of calcium ions in ceramics used as bone replacement materials for the treatment of bone fractures and defects caused by osteoporosis. The aim of this study was to summarize current knowledge about the role of strontium in the treatment of osteoporosis, its effects (in various forms), and the ways in which it is administered.

Here's my ICP as a proof:

 

[Randy Holmes-Farley]

Thank you @Randy Holmes-Farley , that's what I also found on Wikipedia - the chemical similarity of Ca and Sr molecules, which seemed to fit. Thank you for confirming it. Nonetheless, I've also found info that doctors recommend using strontium in case of osteroporosis to increase density and strenghth of human bones - and allegedly the same happens to corals skeletons, depleted strontium weakens them or even a few claim that deficiency may decrease their growth rate. It's hard for me to backup the second assumption / observation, but



Here's my ICP as a proof:

I don't think that rationale is correct.

There is no scientific study that demonstrates that idea for coral skeletons that I have ever seen.

Coral skeletons are made of a different chemical (calcium carbonate) than are human bones, which have a far more complicated composition that is not calcium carbonate:

Bone mineral: new insights into its chemical composition

Bone mineral: new insights into its chemical composition - Scientific Reports

Some compositional and structural features of mature bone mineral particles remain unclear. They have been described as calcium-deficient and hydroxyl-deficient carbonated hydroxyapatite particles in which a fraction of the PO43− lattice sites are occupied by HPO42− ions. The time has come to...

www.nature.com

Also, the idea that strontium is useful to promote bone strength is not generally accepted fact. It is not approved in the USA and does not provide its benefit by incorporation into the bone material, but by influencing cells to grow differently:

Osteoporosis treatment: Stronium ranelate

Information about stronium ranelate and how it is used as a treatment for osteoporosis.

theros.org.uk

"Strontium ranelate slows down the cells that break down bone. It may also increase the activity of cells that build bone. It works in a different way to other osteoporosis drugs. But it doesn't appear to be any more effective at reducing your risk of broken bones."