Alk seems to participate when doesed

[pwk5018]

Hi

I have an 180 with a 75 sump reef set up.
Ca 400
Alk 7
Mg 1350

I want to raise my alk back to 9 like it use to be so i have been adjusting my dosing. I use the BRS supplements. I noticed when the alk would drip into the water, it solidified once there. Why is this happening? will it still increase my alk? or is it useless now.

 

[Crabs McJones]

Hi

I have an 180 with a 75 sump reef set up.
Ca 400
Alk 7
Mg 1350

I want to raise my alk back to 9 like it use to be so i have been adjusting my dosing. I use the BRS supplements. I noticed when the alk would drip into the water, it solidified once there. Why is this happening? will it still increase my alk? or is it useless now.

Welcome to R2R!

#WelcometoR2R
Are you dripping in a high flow or low flow area? If it's precipitating out you may need more flow in the area you're dripping it

 

[Randy Holmes-Farley Verified Community Expert]

It is normal for there to be a temporary precipitation of magnesium hydroxide when a high pH additive is added to seawater. It redissolves when it mixes in.

 

[Orm Embar]

It is normal for there to be a temporary precipitation of magnesium hydroxide when a high pH additive is added to seawater. It redissolves when it mixes in.

So, when adding either calcium chloride or sodium bicarbonate (or sodium carbonate), the white precipitate redissolves so you don't need to worry about fast additions leading to something insoluble? I always figured that it was calcium carbonate precipitating out due to local concentrations being high enough to precipitate.

 

[Randy Holmes-Farley Verified Community Expert]

So, when adding either calcium chloride or sodium bicarbonate (or sodium carbonate), the white precipitate redissolves so you don't need to worry about fast additions leading to something insoluble? I always figured that it was calcium carbonate precipitating out due to local concentrations being high enough to precipitate.

There should be no precipitate on adding calcium chloride.

There is a temporary precipitate (magnesium hydroxide) on adding high pH additives of all kinds, including sodium carbonate. But you want to mix it in before it has a chance to make a permanent precipitation of calcium carbonate, which is slower but more problematic.

This is normal:

What is that Precipitate in My Reef Aquarium? by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2005-07/rhf/index.htm

Figure 3. The transient cloud of magnesium hydroxide that forms when high pH additives are added. In this case, the alkalinity portion of B-ionic was added to a fairly still portion of one of my reef aquaria.