How does lanthanum chloride react with phosphate/

[reefkeeper2]

I have been dosing lanthanum into a vortex filter charged with diatomaceous earth and powdered carbon. This method has worked incredibly well in redusing phosphates in my tank to 0. Even my most previously sensitive animals (clams) showing no signs of stress as when I dosed using filter socks. My question is , how does lanthanum react with phosphates, what is the resulting precipitate made of, and will excess free lanthanum be removed by the powdered carbon in the filter?

 

[Boomer]

Lanthanum chloride, dissociates to La++ and Cl- in water.

LaCl3 + H2O(d) ===> La+++ + Cl - + H20.

The La+++ then combines with PO4.

La+++ + PO4- + H20 ===> LaPO4 , Lanthanum phosphate , a precip like CaCO3

This can only be remove mechanical and running it through submicron filters, some by skimming and some kind of sediment trap. Basically, that is what you are doing with DE and PC, as it is acting as a sediment trap and a submicron filter. So, the effluent, should hopefully, greatly reduce any getting into the tank. However, there is also the issue of La++ combining with CO3-- to give Lanthanum carbonate.

La+++ + CO3-- ===>La2(CO3)3, a precip salt like CaCO3.

This can reduce your Alk

And some La+++ will sneak through.

 

[chaderic26]

Where do you buy the Lanthanum chloride from?

 

[bertoni]

There are a number of products that contain it. I think all of the liquid phosphate removers have it. Blue Life is one of them.

 

[reefkeeper2]

I'm using Seaclear that I bought at a local pool company.

 

[reefkeeper2]

Oh, and thanks Bertoni, that's just what I wanted to know

 

[Mcubed]

<a href=showthread.php?s=&postid=15424912#post15424912 target=_blank>Originally posted</a> by Boomer
Lanthanum chloride, dissociates to La++ and Cl- in water.

LaCl3 + H2O(d) ===> La+++ + Cl - + H20.

The La+++ then combines with PO4.

La+++ + PO4- + H20 ===> LaPO4 , Lanthanum phosphate , a precip like CaCO3

This can only be remove mechanical and running it through submicron filters, some by skimming and some kind of sediment trap. Basically, that is what you are doing with DE and PC, as it is acting as a sediment trap and a submicron filter. So, the effluent, should hopefully, greatly reduce any getting into the tank. However, there is also the issue of La++ combining with CO3-- to give Lanthanum carbonate.

La+++ + CO3-- ===>La2(CO3)3, a precip salt like CaCO3.

This can reduce your Alk

And some La+++ will sneak through.

Awesome! Thanks, I just learned a lot.

 

[reefkeeper2]

Boomer, does the carbon have the ability to absorb any of the La+++?

 

[bertoni]

It might remove a bit if the lanthanum bound with an organic, but not enough to be of much interest.

 

[Boomer]

As far as La+++ goes no, anymore than it can remove Ca++. Will GAC remove "a" ion or two ? Yes, just as it can remove a ion or two of Ca++. It is not tha GAC can not remove cations, it can, such as Copper, Iron, Mercury, Lead and other heavy metals but not La++. There are certain GAC that are impregnated with metals for removing La++ but you do not want to be using those, just like certain clays and zeolite will through ionic-exchange, which is about useless in seawater.

 

[HighlandReefer]

ReefKeep2,

You may find this thread interesting regarding lanthanum being used in large municipal aquariums:

Lanthanum Chloride - Aquality Symposium
1st International Symposium of Water Quality & Treatment in Zoos & Aquaria
http://www.aqualitysymposium.org/ph...start=15&sid=743e4532e14958f81b2c0f99e527b7f2

 

[reefkeeper2]

Thanks!

 

[chaderic26]

I'm using Seaclear that I bought at a local pool company.

Could you give a little info about how long you've been dosing this product, The full name of it, and a little about your dosing schedule.

Amounts and such.

I would appreciate it.

Chad

 

[chaderic26]

Forgive my acronym ignorance. What's DE and PC?


.........(that is what you are doing with DE and PC)

 

[reefkeeper2]

De = diatomaceous earth. PC = powdered carbon. I have been experimenting with lanthanum for almost a year. Initially I injected it into a skimmer and filtered the effluent into a 10 micron filter sock. I tried different concentrations and amounts. The product I use is called seaklear and can be bought at pool supply companys. There are other lanthanum based products you can use as well, some marketed just for aquaria but it's all lanthanum chloride.
Using the method described above phosphate levels were reduced, but I could not get them lower than 0.03ppm. Also, I would sometimes get negative reactions from my clams when I dosed. This meant some of the precipitate was still getting into the tank. Although not toxic, the precipitate can be irritating to some fish (tangs especially) and inverts. Now I use 10ml of seaklear mixed with 60ml of water and inject it into the vortex filter at a rate of 2 -4 ml \ hour. 4ml per hour seems to work best. The filter clogs when about half of this is used up. I don't have a schedule as to how often I will do this yet.
Injecting the lanthanum into the diatom filter appears to be a huge improvement. No reactions from any of the livestock. Also, I can get the phosphates down to 0 ( milwakee meter). For me and my large tank, this is a great alternative to GFO.

 

[chaderic26]

It sounds like a good alternative. I'm burning through GFO pretty fast at the moment and also burning a whole in my wallet.