snowstorms

[tmc]

have read that these are bad but what do they look like, probably a snowstorm just guessing though but seriously how do they happen and furthermore how do you remedy this. think i may have one

salinety is 1.24
ph is 8.3
cal. is 420
alk. is @14

thanks in advance troy

[tmc]

forgot to mention that i started using b-ionic about 3 days ago, recommended dosage.

[Witfull]

snowstorms do look like fresh powder snow all over everything, its cause by more disolved solids than the water can hold. (where is cheeks with his Marble Analogy?) to much salt, Ca, alk, trace elements cause them to precipitate from the water.

[Gina]

I have been trying to find some info on this also and spent about an hour yesterday without any real luck.

So, Boomer or cheeks......you guys have any info regarding this?

[RANDY]

Perhaps Your Calcium Us Exceeding 420 Ppm. This Can Cause Supersaturation And Subsequent Precipitation Of Available Calcium Carbonate. This Sucks The Trace Elements Out Of Your System. Just Lower Your Calcium Levels Via Water Changes And Top Ups With Ro/di Water, And The Problem Will Be Reigned In! Good Luck.

[Woodstock]

WHAT IS THAT PRECIPITATE IN MY REEF AQUARIUM?

Precipitates on Heaters and Pumps



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The precipitate that forms on heaters (Figure 2) and pumps is primarily calcium carbonate. Natural seawater and reef aquarium water is often supersaturated with calcium carbonate, but the precipitation is kept at a very slow pace, primarily by magnesium ions (for reasons described later in this article). Certain factors, however, push the supersaturation even higher, and the "pressure" to precipitate becomes too high for the magnesium to prevent it. These factors include elevated calcium, alkalinity, pH, and in the case of heaters and pumps, elevated temperature. How these factors impact supersaturation is detailed later in the article, but the following section summarizes the effects.


Figure 2. Calcium carbonate can form thick deposits on heaters.
It is the heat itself that helps drive this precipitation.

Chief among the factors causing precipitation are alkalinity and pH. While most aquarists would be unlikely to have in their aquaria double the calcium level of natural seawater (more than 800 ppm), many folks have doubled its supersaturation level via alkalinity and pH. With all other things being similar, for example, an aquarium with a pH of 8.5 has twice the supersaturation of one with a pH of 8.2, and an aquarium with a pH of 8.2 has twice the supersaturation of one with a pH of 7.9.

Alkalinity, likewise, can be a big contributor to precipitation. Many aquarists push alkalinity to elevated levels, approaching or exceeding twice the naturally occurring levels (about 2.5 meq/L, or 7 dKH). That change can, in turn, double the supersaturation.

Elevated temperature impacts calcium carbonate precipitation in two ways: 1) by simply reducing the solubility of CaCO3 (which is more soluble at lower temperatures) and 2) by causing the formation of additional carbonate from the bicarbonate in solution. These effects are roughly similar in magnitude, and are one of the reasons that pumps and heaters can be more rapidly coated with calcium carbonate precipitate than other objects in the same aquarium.

Another possible reason that pump impellers and heaters get coated more rapidly than other surfaces is that such surfaces may be less likely to become coated with a film of bacteria that prevent calcium and carbonate from reaching the surface. Heaters may become too hot for such bacterial films to form properly, and pump impellers may have enough water motion around them to wash away bacteria as soon as they begin to attach. Exactly how large such effects are, however, is not clear to me.

Low magnesium can also contribute to precipitation because magnesium interferes with the precipitation of calcium ions. Normally, magnesium ions slip into spots where calcium would otherwise bind, altering the surface's structure so that it no longer is a good seed crystal for further calcium carbonate precipitation. Fewer magnesium ions in solution makes this process less effective.

Finally, it appears that ferric ion (Fe+++) may help initiate the precipitation of calcium carbonate. Such ions may be added directly in some products, and can be released from iron-based phosphate binders such as Rowaphos, Phosban, and Phosphate Killer.

[cheeks69]

Originally Posted by Witfull

snowstorms do look like fresh powder snow all over everything, its cause by more disolved solids than the water can hold. (where is cheeks with his Marble Analogy?) to much salt, Ca, alk, trace elements cause them to precipitate from the water.

Fact: it is only possible to dissolve so many solids into a given volume of water (calcium, carbonates, and everything else). At the risk of oversimplifying the dynamic, imagine a bowl that holds one hundred marbles representing the total dissolved solids in seawater in a given system. If red marbles represented calcium, and blue marbles represented carbonates (alkalinity), the bowl can still only hold one hundred marbles no matter what mix of color they are. Now, if seventy marbles were the equivalent of 400-ppm calcium and the remaining marbles were blue, the only way to increase calcium would be to displace alkalinity (to remove blue marbles). In troubled systems, the misapplication of calcium supplements (dosing suddenly or to excess) is known to cause a sudden precipitation of carbonates (the alkalinity falls/crashes) that is commonly referred to as a “snowstorm”. It is instigated by the influx of a large or rapid amount of calcium entering the system that spikes the pH immediately surrounding carbonate molecules and causes a crystalline precipitation (fallout). In keeping with our analogy, a “snowstorm” would be like taking another bowl of one hundred red marbles (calcium) and trying to pour it into the original bowl of mixed, colored marbles (balanced calcium and alkalinity). The result is the displacement of all blue marbles (carbonates/alkalinity) and the overflow of excess red marbles beyond the one hundred marble limit. The ramifications of this in an aquarium is a crash in water chemistry and water quality that cannot be corrected while the chemical reaction occurs. Dosing more supplements to try to correct the imbalance (or even doing a concurrent water change with hopes of dilution) will only serve to feed the chain reaction. Tragically, the “snowstorm” must be allowed to finish and an aquarium system is traumatized in the process.

To safely avoid dangerous imbalances in the Ca-Alk dynamic, aquarists simply need to avoid pushing either component to an extreme end or both simultaneously high. Instead, think of the relationship as a Hi-Lo situation within the safe ranges. Within the accepted ranges (350-450 ppm Ca and 8-12 dKH Alk), one parameter can be pushed to a high end while the other is allowed to stray toward the middle or lower end. Any reasonably mix of the two will still provide more than enough of both elements for successful calcification. More importantly, consistent levels of both are far more supportive of growth in calcareous organisms than the inconsistent but high average of either component otherwise. Many aquarists enjoy phenomenal growth in their reef creatures with rather modest Ca and Alk levels. Indeed, consistency with all aspects of aquatic husbandry is more conducive to success than random high points.

http://www.wetwebmedia.com/calcalkmar.htm