Brown hard substance building up in water container

[HornetMech242]

I have a brute can that i keep salt water mixed up at all times. Inside on the sides and on the circulation pump there is a brown coraline like substance building up. What is this and how do i prevent it? Today i drained the container discarded the water and cleaned it out really well. I put it in this forum since i thought there was something in the water that would cause it. It is RO/DI water that i mix the salt with.

Chris

[mr.maroonsalty]

I believe its a bacteria. I get it in my containers more when I season my mix for a couple days; I rinse/wipe it out before I put the pail away, or before I fill it again, whichever comes first.

[ricde]

If your using Reef Crystals, it's a pretty common thing. There's a couple of threads discussing it but the consensus seems to be it's harmless

[Aquarist007]

Yes, it is a harmless precipitate. I think it was stated previously that it is a compound of magnesium that is precipitating out because of the higher levels of magnesium in the new salt mixes like Instant Ocean and h2ocean.

[HighlandReefer]

"What is that Precipitate in My Reef Aquarium?"
http://reefkeeping.com/issues/2005-07/rhf/index.htm

From it:

"Solid Residues Remaining After Preparing Artificial Seawater



--------------------------------------------------------------------------------

Most salt mixes leave behind a solid residue when dissolved, although the extent to which this occurs varies from brand to brand. I use Instant Ocean and rarely clean out the 44-gallon trashcan that I mix it in, so a significant residue builds up over time (Figure 1). In preparation for this article I removed some of this solid material, and found that it could be almost completely dissolved in hydrochloric acid with lots of bubbling. This demonstrates that these solids were probably calcium carbonate (CaCO3), perhaps also containing magnesium. Pure magnesium carbonate is undersaturated in seawater (which is detailed in later sections of this article) 1 and should dissolve in marine systems, so it isn't likely to be the precipitated material, although there may be significant magnesium in the calcium carbonate.

http://www.reefkeeping.com/issues/2005-07/rhf/images/Figure_1sm.jpg

Figure 1. The residue on the bottom of the plastic trash can that I use to mix Instant Ocean. I rarely clean it out. The solid is most likely calcium carbonate.

Based on the fact that the material exists as sheets that clearly did not arrive in the mix (as opposed to a fine powder which might have), I conclude that at least a significant fraction of this residue formed in the barrel. I cannot, however, rule out the possibility that some solid calcium or magnesium carbonate may have existed in the salt mix and was cemented together by additional precipitation of calcium carbonate during dissolution or storage.

When salt mixes are dissolved, there exist local regions where the salt concentration is very high. In those local regions, the calcium and alkalinity must also be very high. In fact, as seawater is concentrated by evaporation, there is a well-established series of minerals that precipitate as the salinity increases. In this series, calcium and magnesium carbonate are the first to precipitate, appearing at a specific gravity of about 1.140, which is about a 50% solution of salt in water.1 Such conditions may well exist on the bottom of a saltwater reservoir as the salt is dissolving.

With some mixes (but not the Instant Ocean that I use), the initial pH on dissolution may be very high (pH 8.5-9 +). As shown in detail later in this article, pH can play a dominant role in determining the rate of calcium carbonate precipitation, and such a high pH would make it more likely to precipitate.

It has been suggested by some aquarists that some salt mixes may contain anti-caking agents, such as clays. I do not know if this is true, but if it is, they may form part of the residue that is left behind after dissolution.

In order to minimize the formation of insoluble carbonate salts when mixing, the following suggestions may be helpful:

1. Add the salt to a full batch of water, rather than adding water slowly to a large batch of salt. The latter allows a greater time at much higher than natural seawater salinity, which may tend to precipitate calcium and magnesium salts.

2. Stir the mixture vigorously as it is being dissolved.

3. If using a mix with a high initial pH, aerate the mixture as well as stirring it. The aeration will reduce the pH."

[tmz]

I get it too. It is not harmful.

[Aquarist007]

I get it too. It is not harmful.

really---is it contagious:lol2:

[Aquarist007]

"What is that Precipitate in My Reef Aquarium?"
http://reefkeeping.com/issues/2005-07/rhf/index.htm

From it:

"Solid Residues Remaining After Preparing Artificial Seawater



--------------------------------------------------------------------------------

Most salt mixes leave behind a solid residue when dissolved, although the extent to which this occurs varies from brand to brand. I use Instant Ocean and rarely clean out the 44-gallon trashcan that I mix it in, so a significant residue builds up over time (Figure 1). In preparation for this article I removed some of this solid material, and found that it could be almost completely dissolved in hydrochloric acid with lots of bubbling. This demonstrates that these solids were probably calcium carbonate (CaCO3), perhaps also containing magnesium. Pure magnesium carbonate is undersaturated in seawater (which is detailed in later sections of this article) 1 and should dissolve in marine systems, so it isn't likely to be the precipitated material, although there may be significant magnesium in the calcium carbonate.

http://www.reefkeeping.com/issues/2005-07/rhf/images/Figure_1sm.jpg

Figure 1. The residue on the bottom of the plastic trash can that I use to mix Instant Ocean. I rarely clean it out. The solid is most likely calcium carbonate.

Based on the fact that the material exists as sheets that clearly did not arrive in the mix (as opposed to a fine powder which might have), I conclude that at least a significant fraction of this residue formed in the barrel. I cannot, however, rule out the possibility that some solid calcium or magnesium carbonate may have existed in the salt mix and was cemented together by additional precipitation of calcium carbonate during dissolution or storage.

When salt mixes are dissolved, there exist local regions where the salt concentration is very high. In those local regions, the calcium and alkalinity must also be very high. In fact, as seawater is concentrated by evaporation, there is a well-established series of minerals that precipitate as the salinity increases. In this series, calcium and magnesium carbonate are the first to precipitate, appearing at a specific gravity of about 1.140, which is about a 50% solution of salt in water.1 Such conditions may well exist on the bottom of a saltwater reservoir as the salt is dissolving.

With some mixes (but not the Instant Ocean that I use), the initial pH on dissolution may be very high (pH 8.5-9 +). As shown in detail later in this article, pH can play a dominant role in determining the rate of calcium carbonate precipitation, and such a high pH would make it more likely to precipitate.

It has been suggested by some aquarists that some salt mixes may contain anti-caking agents, such as clays. I do not know if this is true, but if it is, they may form part of the residue that is left behind after dissolution.

In order to minimize the formation of insoluble carbonate salts when mixing, the following suggestions may be helpful:

1. Add the salt to a full batch of water, rather than adding water slowly to a large batch of salt. The latter allows a greater time at much higher than natural seawater salinity, which may tend to precipitate calcium and magnesium salts.

2. Stir the mixture vigorously as it is being dissolved.

3. If using a mix with a high initial pH, aerate the mixture as well as stirring it. The aeration will reduce the pH."


thanks cliff--I added this great information to the Capn's Log book thread

http://www.reefcentral.com/forums/showpost.php?p=16975565&postcount=178

[HighlandReefer]

Your welcome. I can't say it better than Randy does in his article. :lol:

[tmz]

really---is it contagious:lol2:

:bounce2:Only if you eat it.:wildone:

[bertoni]

Actually, I suspect it's mostly calcium and magnesium carbonate, which is pretty much just Tums.

[Aquarist007]

Actually, I suspect it's mostly calcium and magnesium carbonate, which is pretty much just Tums.

no wonder I don't get an upset stomach when I siphon some of it:bounce1:

[tmz]

Watch it Scott, keep sucking that up and you'll grow hair algae in your ears.

[Aquarist007]

Watch it Scott, keep sucking that up and you'll grow hair algae in your ears.

How about my head---I need it there more then in my ears:idea:

[bertoni]

Life is not that kind. :)