“Healthy reefs don’t just happen, they’re built element by element. The right balance of calcium, magnesium, alkalinity, and trace elements is the foundation of every thriving coral skeleton.”
What is Hydroshock?
Hydroshock is a 3-part dosing system, formulated and produced by Canadian brand Reef Charge, to give your tank the balanced elements it needs to thrive. Depending on the type of the coral in your tank, the dosing will differ and fluctuate as the corals grow. The bigger the coral grows the more components the skeletons need in order to create a strong base. Different coral skeletons (or lack thereof) require different elements. Hydroshock is a balanced blend of Calcium, Alkalinity, Magnesium, Iodine, and other trace/minor elements.
Why is it a 3-part?
Hydroshock is a 3-part dosing system as opposed to an 1-part or 2-part due to the reactivity and importance of each element in the bottles. Certain elements such as Calcium and Magnesium react together causing Magnesium to precipitate out of the bottle. Meaning that Magnesium is no longer usable due to it being bound with other chemicals, or being degraded over time. This is a large part of why we chose three bottles instead of two, as proper ratios are vital to a healthy reef.
Additionally, through reef keeping and weekly testing, we had noticed some big issues not just in our tanks, but our customers. Specifically, SPS corals would do well for a few weeks, then slowly degrade at their bases over time due to thin, weak skeletons. We also encountered slow growth and had accepted that maybe we just couldn’t keep some corals as do many hobbyists. SPS issues are commonly treated as an alkalinity problem, which certainly can be the case especially with instability, but it made us dig deeper into how the coral skeleton was made. We realized that the ratios were incredibly skewed in elements we know were vital to the integrity of the corals, pushing us to create our own blend.
What do corals need to grow?
Depending on the type of coral you keep in your aquarium, they will have different needs. In brief, both SPS and LPS corals need Alkalinity, Calcium, Magnesium, and Strontium, and all soft corals need iodine(1,3,4,6). Below we will break down the main components of the skeletons for both SPS and LPS corals. But first, we have to talk about how the skeleton is formed for each.
SPS
SPS corals are the ones that are most commonly thought of when we talk about dosing components like calcium and alkalinity. They are big, twiggy, have large skeletal components, and are harder than your LPS corals, making it easier to understand why they need calcium and alkalinity. They are a great indicator species for a happy, well balanced tank.
From the very beginning we are told that the coral skeleton takes up Calcium Carbonate and that is what makes the skeleton. While this is true, they are not the only vital components needed to build the skeleton. The best way to explain how the coral skeleton works would be like baking cookies. You can’t make good cookies without baking soda, otherwise the cookies come out flat. But, lots of times we forget how important baking soda is until we have flat mushy cookies! Baking soda is to cookies what Magnesium is to coral. Coral skeletons actually require a lot of Magnesium(1,3,4,8). Both Magnesium and Calcium can bind with bicarbonate to make the skeleton(1,3). Interestingly enough, the preference for magnesium and calcium has fluctuated between different eras(6)! Below we have two images that better demonstrate the role Magnesium plays in forming the skeleton.
Image from:( Meibom et. al, 2004)
The first image shows how Magnesium is distributed from the COC(cite of calcification) or as we may know it, the coralite(3,4,8). What the COC is, or at least how we can visualize it is: the “mouth piece.” The mouth piece is the part where the mouth forms(or in some species like hammers and torches, it is where the polyps are pushed out of) and is usually shaped like small volcanoes or big divots depending on the species. What the image on the left shows is that Magnesium is actually uptaken the most at the COC’s and then used to build outward in fluxes(3,4,8). The corals are able to control the amount of Magnesium taken up through a fluid membrane which causes the gradients you see in the image on the left(1,3,4). The green and red stippling being the highest concentration of Magnesium and blue being lowest. As you can see, Magnesium plays a vital role in the formation of the “mouthes” and formation/strengthening of the new skeleton(1,3,4,7). Magnesium almost acts as both a glue that holds the skeleton together and the skeleton itself which creates the growth rings we see(1,3,4,7). This is because Magnesium and Calcium have similar structures and properties, so both are bound with bicarbonate to create the skeleton(3,4,8).
This is better explained in the second image. As we mentioned before, we need different “ingredients” to build a proper skeleton. Calcium(yellow) and bicarbonate(yellow) are the start and form the new edges, then Magnesium(blue) comes and layers itself overtop of calcium to build and strengthen the new skeleton, with strontium(and in some cases sulphur) working to create a strong backbone.
Thus, in order to ensure every tank gets the elements needed to create the skeleton, we have separated the elements according to their reactivity and concentrations into three separate bottles. They are made to be dosed at a 1:1:1 ratio, or changed to meet the needs of your tank.
LPS
LPS has many of the same elemental needs as SPS corals. Especially species like Hammers, Duncans, Torches, Blastomussa, Chalices, Goniopora, etc. For those species, Magnesium and Alkalinity are as important in the skeleton building process as with SPS corals(3,5,7). It has been commonly expressed in the community and research that Goniopora often do better with Magnesium supplementation.
It has also been shown that elements such as Iodine, have helped in boosting coral health by acting as a type of cleanser(2,5). LPS corals can be finicky, so adding small doses of Iodine(which naturally occurs in the ocean), can help fight off disease and infection from within the tank(2,5). Species like Torch and Hammer corals are especially prone to polyp bail out, which is why we decided to include iodine into our regular dosing regimen. The use of iodine is both an antibacterial and antiviral aids in the fight against diseases like brown jelly disease, white band disease and more(2,5).
Softies and Zoas
Softies and Zoas are different, as they don’t have a “skeleton” per say. What they do have is layers of tissue stacked on top of one another. While they don’t have a skeleton, they still require a “glue” to hold the layers of tissue together. Just like Magnesium acts with SPS and LPS, Iodine is used to “glue” the layers of tissue together(2,5). While Iodine is generally used as a treatment for pests or as a “cleanse”, it is actually necessary for some corals! This is another reason we have included Iodine into our Part 3, as we want to meet every coral's needs, not just some.
Sources
- Callahan, K. M., Casillas-Ituarte, N. N., Xu, M., Roeselová, M., Allen, H. C., & Tobias, D. J. (2010). Effect of magnesium cation on the interfacial properties of aqueous salt solutions. The Journal of Physical Chemistry A, 114(32), 8359-8368.
- Klinges, J. Grace, et al. "Common aquarium antiseptics do not cause long-term shifts in coral microbiota but may impact coral growth rates." Frontiers in Marine Science 10 (2023): 1281691.
- Meibom, A., Cuif, J. P., Hillion, F., Constantz, B. R., Juillet‐Leclerc, A., Dauphin, Y., ... & Dunbar, R. B. (2004). Distribution of magnesium in coral skeleton. Geophysical Research Letters, 31(23).
- Neder, M., Laissue, P. P., Akiva, A., Akkaynak, D., Albéric, M., Spaeker, O., ... & Mass, T. (2019). Mineral formation in the primary polyps of pocilloporoid corals. Acta biomaterialia, 96, 631-645.
- Prouty, N. G., Roark, E. B., Mohon, L. M., & Chang, C. C. (2018). Uptake and distribution of organo-iodine in deep-sea corals. Journal of Environmental Radioactivity, 187, 122-132.
- Reed, Emma & Thompson, Diane & Cole, Julia & Lough, Janice & Cantin, Neal & Cheung, Anson & Tudhope, A.W. & Vetter, Lael & Jimenez, Gloria & Edwards, R.. (2021). Impacts of Coral Growth on Geochemistry: Lessons From the Galápagos Islands. Paleoceanography and Paleoclimatology. 36. 10.1029/2020PA004051.
- Reymond CE, Hohn S. An Experimental Approach to Assessing the Roles of Magnesium, Calcium, and Carbonate Ratios in Marine Carbonates. Oceans. 2021; 2(1):193-214. https://doi.org/10.3390/oceans2010012
- Yus Domínguez, Joaquín Luis & Nixon, E & Li, J & Gimenez, J & Bennett, Matthew-James & Flores, D & Marhaver, K & Kelly, L & Wagoner Johnson, Amy. (2024). Composite substrates for coral larval settlement and reef restoration based on natural hydraulic lime and inorganic strontium and magnesium compounds. Ecological Engineering. 202. 107236. 10.1016/j.ecoleng.2024.107236.