Worldreefs.info – Roiy's Reef

The Importance Of Calcium – Magnesium – And Kh In Aquariums

Many aquarists overlook the need for calcium, electrolytes, magnesium and the effect of a proper KH (Carbonate hardness) in their freshwater aquarium. KH is basically the buffering capacity of your aquarium, a Kh above 80 ppm helps prevent sudden drops in ph (You can convert dH [German hardness] ppm by multiplying your dH by 17.9). This is especially important with livebearers, goldfish, African cichlids, brackish and many other freshwater fish. The production of Nitrates (nitric acid) will slowly reduce your ph, but a proper KH will keep a more stable ph. This is important to note, if your KH is low and your ph has been dropping, a large water change (don't get me wrong, water changes are VERY important) can cause stress on your fish, or even kill them.

Another consideration of KH is that you can generally safely add the buffers (both freshwater and saltwater) that effect KH without sudden changes in chemistry (unless your KH is under 80 ppm already), unlike a direct ph or GH change. For this reason you do not always have to check your KH before adding buffers such as Wonder shells.

Baking Soda (Sodium Bi-Carbonate HCO3-), is often used for KH, Sodium Bi-Carbonate will buffer at 8.0 to 8.2. They are very good at buffering at that pH. Just a little carbonate will absorb free H+ ions, and this causes alkalinity (which is the lack of H+ ions). To stop the carbonate ions from consuming too much H+ and to keep a pH of 7.0 we need to restrict the amount of Baking Soda used, as it is always looking for H+ ions to consume. This is why I prefer using Calcium based products, Wonder Shells being my first choice, aragonite my second.

If you have a very unstable KH level (drops rapidly), look into causes such as a large amount of decomposing organic material. The more organic break down (de-nitrification), the more acids produced. Some filters if not cleaned regularly can cause this; including canister, UGF, and Wet/Dry.

GH

General hardness (GH) refers to the dissolved concentration primarily of magnesium and calcium ions. Both Calcium and magnesium are important for proper internal osmotic processes in fish (and invertebrates). Other ions can contribute to water hardness but are usually insignificant and difficult to measure. When fish are said to prefer "soft" or "hard" water, it is GH, not the kH that is being referred to. GH will not directly affect pH although "hard" water is generally alkaline due to some interaction of GH and kH.

CALCIUM CARBONATE:

Calcium carbonate in your aquarium will keep a more stable Kh, while magnesium is another important element that works with calcium. A proper amount of Calcium and Magnesium in your aquarium will affect the fish’ health positively. Besides helping to keep a stable Kh, magnesium and calcium have been shown to increase resistance to degenerate diseases by lowering the acidity in the body. This will help with prevention of ich, fungus, and general “wear and tear” in your fish. Calcium also helps in healing and stress, and without proper calcium levels healing may be difficult or impossible. The addition of antibiotics (such as Tetracycline) will lower calcium absorption.
Another note about calcium; Calcium is very important to proper discus health, yet calcium can adversely affect the pH of a discus aquarium, which is generally kept at a pH below 6.5. I have successfully used calcium (Wonder Shells or Calcium Polygluconate) in discus aquariums by using a mix of RO (Reverse Osmosis) water and tap water (dilution will vary depending on your tap and tank water parameters). I then add electrolytes to the RO water and add peat to the filters. I have used this method successfully with discus and added the needed calcium with no pH climb.

Other needs for calcium:

• Calcium is a vital component in blood clotting systems and also helps in wound healing.

• Calcium helps to control nerve transmission, and release of neurotransmitters.

• Calcium is an essential component in the production of enzymes and hormones that regulate digestion, energy, and fat metabolism.

• Calcium helps to transport ions (electrically charged particles) across the membrane.

• Calcium is essential for muscle contraction.

• Calcium assists in maintaining all cells and connective tissues in the body.

Other needs for Magnesium:

• Normal calcium balance in organs

• Healthy muscles

• Healthy nerve transduction

• Healthy calcium balance in blood vessels

ELECTROLYTES;

Electrolytes are molecular substances containing free ions which behave as an electrically conductive agent. In fish (or other living things) the primary ions of electrolytes are sodium (Na+), calcium (Ca++), potassium (K+), magnesium (Mg++), chloride (Cl-), phosphate (PO4—), and hydrogen carbonate (HCO3-).
Fish and other aquatic life forms require both a subtle and complex electrolyte balance between the intracellular (inside the cell) and extra cellular (outside the cell such as plasma membranes) environment. In particular, the maintenance of precise osmotic gradients (or differences) of electrolytes is important. These gradients affect and regulate the hydration of the fish, blood pH, and disease resistance and are important for proper nerve and muscle function.

A product called a “Wonder Shell” will help with your calcium, magnesium, and Kh of your aquarium. Wonder Shells also come in a medicated version for control of aquarium ich and fungus. Here are a few of their attributes:

* Helps keep aquarium clear

* Maintains stable ph

* Adds necessary minerals (electrolytes)

* Removes chlorine

* Great for Goldfish, livebearers, cichlids, and more

* Contains Calcium carbonate; sodium thiosulfate; major, minor, and trace elements including magnesium sulfate. Magnesium and calcium been proven to help fish (and humans) during stress and to help prevent disease due to acid buildup in the body.

For my full expanded article:
CALCIUM, KH, AND MAGNESIUM IN AQUARIUMS; How to maintain a Proper KH, why calcium and electrolytes are important.

It is always best to have as many different test kits as you can afford (as they apply to either freshwater or saltwater

I prefer to purchase my test kits separately as most master test kits duplicate test I do not need (high range and low range ph) and leave out ones I need such as kH and GH, or possibly Phosphate, Calcium, or Redox

Here is a list of FRESHWATER Test Kits, what they are for and in order of importance:

[1] Ammonia Test Kit; Ammonia is very toxic even at low levels, should be kept at or near 0. Ammonia test kits cannot discern between highly toxic ammonia (NH4) and only slightly toxic ammonium (NH3). Products such as Prime , Ammolock, and Amquel will convert NH4 to NH3, so your toxic ammonia level will not test accurately after using one of these products. Ammonium (NH3) will convert to NH4 at higher pH levels, which why high ammonia levels as per test are much more toxic at higher pH.

[2] kH & GH Test Kit; you will notice I placed this above a pH test Kit, this due to the fact that a poor kH will make keeping a stable pH nearly impossible. Also Calcium (as tested in GH) is more important to fish health than many aquarists give credit.

*You want to maintain a KH & GH of around 60 ppm (around 2-3 dKH & dGH) for Discus, Rams, Cardinals, and other Amazon fish.

*A KH & GH of 80 -100 for most tropical fish including Gouramis, Bettas, Angelfish, ECT.

*A KH & GH of 100-200 for Goldfish, mollies, Platties, Guppies, ECT.

*A KH & GH of over 200 for Rift Lakes African Cichlids and Brackish fish such as Monos and Scats.

For more information about Calcium and Magnesium, see my article: "Calcium, KH, and Magnesium in aquariums; How to maintain a Proper KH, why calcium and electrolytes are important".

[3] pH High Range OR Low Range Test Kit; you should only need one or the other based on the type of aquarium you keep.
Does not stress over being exact about pH, as too of many aquarists go WAY overboard here! For example Discus generally do best around 6.5, however I know breeders of Discus using water with a pH well over 7.0

I recommend a High Range Test Kit for Goldfish and livebearers which should have a targeted pH of about 7.5-7.8. Rift Lake African cichlids should have a pH of over 8.0
I recommend a Low Range Test Kit for general community freshwater fish (6.8- 7.4) or Amazon River fish (under 6.8)

[4] Nitrate Test Kit; this test is important to know when to change your water (along with KH), as well as how well your general long term tank health is going. Nitrates will also show you how well your plants are consuming nitrogenous nutrients, and if you are vacuuming the aquarium properly such as removing all the mulm. Some filters such as Under Gravel in particular, and Wet Dry and Canister filters can become nitrate factories if not taken care of properly.
For most freshwater fish a nitrate level under 40 ppm is correct or above 15 ppm for planted aquariums.

[4] Nitrite Test Kit; you will notice I put it last, not because it is not important, only that if budget is a concern or time for testing is a factor, this parameter mirrors ammonia often within hours or days. Nitrite should be at or near 0.

[5] Phosphate Test Kit; generally only necessary in planted aquariums where large amounts of ‘ferts’ (fertilizer) are added or if you have uncontrollable algae growth. This test kit is often more important for ponds where rain water can wash debris with high phosphate content into the pond.
Your aquarium (or pond) should have phosphate levels as close to 0 as possible.

[6] Redox Meter; generally this water parameter will take of itself provided you perform proper aquarium husbandry including, regular water changes with properly ionized water, you maintain a GH and KH level of at least 50 ppm (I find 80 ppm better). This said, this is a good parameter to check if you are having problems with Cyanobacteria (Blue Green Algae) or if you are having unexplained problems and every other test is correct (providing you do not have an unknown disease). I recommend every aquarist be at least familiar with the Redox Potential, here is an in depth article about aquarium Redox: “The Redox Potential in Aquariums (& Ponds) and how it relates to proper aquatic health”.

You can use Methylene Blue according to standard dosage to your aquarium water (remove the water for this test), and it stays a brilliant blue, you probably have a positive Redox. If the color dissipates at all (even the slightest) you probably have a reducing number. This test in no way replaces the accuracy of Redox meter, but it is a simple way to get a handle on your aquariums Redox health.
Your aquarium Redox should be around -300 mV.

SALTWATER;

The list remains similar and I will bypass descriptions that are in common with freshwater test kits.

[1] Ammonia Test Kit; this should be 0 as in FW

[2] KH Test Kit; you do not need a GH Test Kit for saltwater. KH (or alkalinity as is called in marine aquariums) should be over 240 ppm (13 dKH)

[3] PH High Range Test Kit; your pH should be between 8.2 – 8.4

[4] Hydrometer; this instrument tests the specific gravity of aquarium water (in simple terms the amount of salts). There are two types; the floating glass hydrometers which are more fragile, but also more accurate or the simple needle hydrometer that you fill with water. It is important with both types of hydrometers to clean these with white vinegar (then rinse thoroughly) to prevent hard water buildup which will then cause inaccurate readings.

[4] Nitrate Test Kit; Nitrates are best under 40 for marine fish aquariums and under 20 (even less if possible) for reef aquariums

[5] Calcium Test Kit; this takes the place of the GH Test Kit in freshwater.
Calcium is important to ALL marine life (this includes freshwater too as it is often sadly overlooked), however it is absolutely essential for proper coral growth in marine aquariums. Bio-availability is also essential, Sea Chem Reef Calcium Polygluconate is probably one of the best, most bio-available calcium supplements available for marine aquariums.
Your marine Calcium levels should be between 400-450 ppm

[6] Nitrite Test Kit; this should be 0 as in FW

[7] Magnesium Test Kit; Magnesium is an essential part of chlorophyll, which is necessary for photosynthesis, plants, including algae and the corals. Maintaining a correct magnesium concentration is very important, and is indirectly responsible for fast coral and calcareous algae growth by virtue of making the maintenance of correct calcium and alkalinity figures possible. Magnesium is depleted by algae and by the use of excessive Kalkwasser. Magnesium is what binds Calcium Carbonate in solution, if levels are low useable calcium levels will also drop. Poor choices of Marine Buffers can further exasperate this problem, this why I STRONGLY recommend Sea Chem Marine Buffer for adjusting alkalinity in marine aquariums (and EVEN freshwater aquariums) as this product has Magnesium, Calcium, and sodium bicarbonate in the proper ratios.
Magnesium levels in marine aquariums should be between 1200 and 1400 ppm.

[8] Redox Meter; as in freshwater, I recommend -300 mV, except Redox is more important in marine aquariums.

[9] Phosphate Test Kit; as in freshwater this should near 0. High phosphate levels in marine aquariums can play havoc with the health and growth of live coral (Phosphates can block the absorption of important minerals)

For the Full Article, including pictures and more links, please visit the site in the resource box below.