Precipitation!

[tredreef]

Ok so for the last month I have been studying up on the reef chemistry forums trying to better understand the relationships between CAL. ALK. and MAG. so that I will be able to get my tank in line with it's peramiters. But there has been one thing that has just stumped me.

Why, when my MAG. levels are up around 1350 - 1400 and my CAL. leveles are up around 450, will my ALK. precipitate out and coat EVERYTHING in the system, and the levels NEVER get above 7.7 - 8.0 dKH?

This is getting frustrating! Please help me understand.:angryfire:

 

[disc1]

What are you supplementing with? pH?

 

[Bio-nut]

Do not feel alone on this topic! It has stumped everyone in this hobby at one point and some of us still have issues with it. I am still not 100% comfortable with it because there are so many variables involved, and I am a chemist and a professional water treater.

To brake down my understanding at the simplest level, reactions such as the formation of Calcium Carbonate (CaCO3) or magnesium carbonate (MgCO3) are driven by the conditions of the environment.

Alkalinity is the most basic measure of the amount of co3 available for calcium and magnesium carbonate formation. The more that you have the higher the level of Alkalinity. This can also be seen in your pH, the more you have the higher you pH will be.

So looking at the pH scale, the reason that we keep our tanks around 8.2 is that it is far enough the alkaline scale to drive the formation of the carbonate form desired for skeleton formation but not so far that you percipitate out all the calcium and magnesium and turn your tank into a cloud. This is a delicate balance, you want to keep enough calcium and magnesium in the tank to allow the corals to grow but not too much that you force it to percipitate.

If you keep the Calcium and Magnesium at the level you have and target your pH around 8.2 you should be just fine. But if any of the level get too high you can expect to percipitate.

As I said before this is my take on it and I always except critisism or additional veiws.

Good luck and hope that this helps.

When it comes to determining where to keep my levels, nature knows best.

 

[Aquarist007]

Ok so for the last month I have been studying up on the reef chemistry forums trying to better understand the relationships between CAL. ALK. and MAG. so that I will be able to get my tank in line with it's peramiters. But there has been one thing that has just stumped me.

Why, when my MAG. levels are up around 1350 - 1400 and my CAL. leveles are up around 450, will my ALK. precipitate out and coat EVERYTHING in the system, and the levels NEVER get above 7.7 - 8.0 dKH?

This is getting frustrating! Please help me understand.:angryfire:

what test kit are you using to test your alk?

 

[tredreef]

What are you supplementing with? pH?

I am supplementing with BRS 2 part. Although this has only been the case for the last week. Previous to that I was using the THRIVE AQUATICS system. The reason for switching was mainly due to cost, BRS is MUCH cheaper, and also I feel that the THRIVE system is not good for an automated system like mine.

what test kit are you using to test your alk?

I use the Red Sea PRO kits for all three and Phosphate.

Do not feel alone on this topic! It has stumped everyone in this hobby at one point and some of us still have issues with it. I am still not 100% comfortable with it because there are so many variables involved, and I am a chemist and a professional water treater.

To brake down my understanding at the simplest level, reactions such as the formation of Calcium Carbonate (CaCO3) or magnesium carbonate (MgCO3) are driven by the conditions of the environment.

Alkalinity is the most basic measure of the amount of co3 available for calcium and magnesium carbonate formation. The more that you have the higher the level of Alkalinity. This can also be seen in your pH, the more you have the higher you pH will be.

So looking at the pH scale, the reason that we keep our tanks around 8.2 is that it is far enough the alkaline scale to drive the formation of the carbonate form desired for skeleton formation but not so far that you percipitate out all the calcium and magnesium and turn your tank into a cloud. This is a delicate balance, you want to keep enough calcium and magnesium in the tank to allow the corals to grow but not too much that you force it to percipitate.

If you keep the Calcium and Magnesium at the level you have and target your pH around 8.2 you should be just fine. But if any of the level get too high you can expect to percipitate.

As I said before this is my take on it and I always except critisism or additional veiws.

Good luck and hope that this helps.

When it comes to determining where to keep my levels, nature knows best.

Thanks for the support. Glad I'm not alone.

 

[bertoni]

The BRS recipe 1 is a high-pH supplement. That might encourage precipitation, particularly if dosed into a small volume of water. Spreading the dose out might help some, if that's not already being done. Getting a second opinion on the test kits might be useful, too. We get reports of bad test kits fairly frequently.