Please Explain Precipitation

revhtree · Jun 16, 2017

For everyone like me can you please explain precipitation a little more in depth and in laymen terms?

What causes it?
How do you know your getting precipitation?
Anything else we should know about it?

Thanks!

austinl · Jun 16, 2017

Tagging alone

GoVols · Jun 16, 2017

revhtree said:
For everyone like me can you please explain precipitation a little more in depth and in laymen terms?

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Tagging along #2...

bblumberg · Jun 16, 2017

How about this one?
https://www.chemicool.com/definition/precipitate.html

A precipitate occurs when one component becomes insoluble in a solution. If there is enough precipitate, you will observe it as a cloudiness in the solution. It is frequently the case that a precipitate occurs as the result of a chemical reaction where the material that precipitates is converted from a soluble, to an insoluble form.

You can observe this by making a solution of calcium chloride as in Randy's 2-part and adding a base to it such as sodium hydroxide. Calcium chloride is soluble in water, adding base converts it to calcium hydroxide, which is not and you see a white precipitate.

Bruce

JimWelsh · Jun 16, 2017

If you're not part of the solution, you're part of the precipitate!

cloak · Jun 16, 2017

Here's another good article regarding precipitation.

http://reefkeeping.com/issues/2005-07/rhf/index.php

GoVols · Jun 16, 2017

bblumberg said:
How about this one?
https://www.chemicool.com/definition/precipitate.html

A precipitate occurs when one component becomes insoluble in a solution. If there is enough precipitate, you will observe it as a cloudiness in the solution. It is frequently the case that a precipitate occurs as the result of a chemical reaction where the material that precipitates is converted from a soluble, to an insoluble form.

You can observe this by making a solution of calcium chloride as in Randy's 2-part and adding a base to it such as sodium hydroxide. Calcium chloride is soluble in water, adding base converts it to calcium hydroxide, which is not and you see a white precipitate.

Bruce

Bruce,
We all know that if you overdose cal and alk at the same time, then you get precipitation and your #'s also drop. Hardened sand, scraping glass etc...

So, In "laymen terms" what is the overdose of cal and alk doing in the reef to cause the precipitation.

Thanks, Freddie

GoVols · Jun 16, 2017

JimWelsh said:
If you're not part of the solution, you're part of the precipitate!

lol!!!!!!!!!!!!

Randy Holmes-Farley · Jun 16, 2017

JimWelsh said:
If you're not part of the solution, you're part of the precipitate!

lol

Randy Holmes-Farley · Jun 16, 2017

revhtree said:
For everyone like me can you please explain precipitation a little more in depth and in laymen terms?

What causes it?
How do you know your getting precipitation?
Anything else we should know about it?

Thanks!

Here's a simplistic explanation that is true in reality.

When a calcium and a carbonate ion randomly hit each other (or a solid calcium carbonate surface), there's a chance they will stick together and form calcium carbonate solid (or stick to the surface). Likewise, a solid calcium carbonate surface is constantly losing ions to the solution.

The more calcium and the more carbonate in solution, the more they hit each other and stick. At some point (in terms of the numbers in solution, called saturation), the number sticking is the same as the number coming off, and no net dissolution or precipitation takes place.

bblumberg · Jun 16, 2017

GoVols said:
Bruce,
We all know that if you overdose cal and alk at the same time, then you get precipitation and your #'s also drop. Hardened sand, scraping glass etc...

So, In "laymen terms" what is the overdose of cal and alk doing in the reef to cause the precipitation.

Thanks, Freddie

Randy answered the question above and in the article linked in post #6. I would only add that the pH of the solution plays a role in which ions are soluble and which precipitate.

Bruce

siggy · Jun 16, 2017

OK define Laymen

GoVols · Jun 16, 2017

Randy Holmes-Farley said:
Here's a simplistic explanation that is true in reality.

When a calcium and a carbonate ion randomly hit each other (or a solid calcium carbonate surface), there's a chance they will stick together and form calcium carbonate solid (or stick to the surface). Likewise, a solid calcium carbonate surface is constantly losing ions to the solution.

The more calcium and the more carbonate in solution, the more they hit each other and stick. At some point (in terms of the numbers in solution, called saturation), the number sticking is the same as the number coming off, and no net dissolution or precipitation takes place.

Randy,
For the sake of Water Chemistry, ;Wacky question. Even if it drives your mag. up to say... 6,000ppm

During an overdose of cal and alk at "one time" (lol)... could you also overdose enough mag "at the same time" to keep the cal and alk ions from binding together?

Regards, GoVols

GoVols · Jun 16, 2017

siggy said:
OK define Laymen

One purpose of mag. is that it keeps the cal and alk ions from binding together for coral intake.
The below is how I'd describe the purpose of mag. in (lol) Laymen...
-------------------------------------------------------------------------------------------------------------------------------------
This is how I keep mag in perspective:
If you want to eat a peanut butter sandwich (for nutrition and building blocks)
Cal = Bread
Alk = Peanut butter
Mag = Saliva ;Drool

(lol)
Try to swallow (intake) a peanut butter sandwich with out or almost no saliva...

-------------------------------------------------------------------------------------------------------------------------------------
The above is what "I" define as "Laymen".

GoVols · Jun 16, 2017

@revhtree
One scenario:
Coral takes in ions separately and not stuck together.

If your mag drops too low then your cal and alk ions will stick together and with precipt. (dust) out. Then you will see that your reef's cal and alk intake will freeze up until you resolve the low mag. issue. Then your reef's cal and alk intake will kick back in over time.

Mag. is like the "Grease" that keeps the cal and alk ions from sticking to each other.

If you run bare bottom and you precipt. out. You can see a dusting on the glass bottom.

Precipitation = Stuck together ions.

siggy · Jun 16, 2017

I asked for that

Randy Holmes-Farley · Jun 16, 2017

GoVols said:
Randy,
For the sake of Water Chemistry, ;Wacky question. Even if it drives your mag. up to say... 6,000ppm

During an overdose of cal and alk at "one time" (lol)... could you also overdose enough mag "at the same time" to keep the cal and alk ions from binding together?

Regards, GoVols

No, I do not think so because you'd precipitate magnesium hydroxide and magnesium carbonate.

GoVols · Jun 16, 2017

Randy Holmes-Farley said:
No, I do not think so because you'd precipitate magnesium hydroxide and magnesium carbonate.

Randy,
I'm sorry but I just had to ask.

Cory · Jun 16, 2017

When ph is high, then calcium and bicarbonate will stick together to make sand. Therefore its not dissolved anymore in the water, it is a rock. Laymen enough?

Calcium chloride + sodium bicarbonate transform into calcium carbonate (rock).

Mono · Jun 21, 2017

Can I hijack this thread?

I've started dosing two part again using Dr. Foster & Smith Sodium Carbonate and Calcium Chloride w/Magnesium Sulfate and Magnesium Chloride to boost Mg.

Using Reef Crystals with salinity at 35 ppt.

Mg was somehow low so I boosted it with 0.5 liter MgSO4+MgCl2 solution to 1400 in a 135 gallon system.

I dose the Sodium Carbonate first into my filter sock (high flow) and it precipitates out immediately forming large white flocks.

Not sure how to fix this? Any advice?