Lanthanum Chloride in Top Off Water

[hart24601]

Hey Randy, I know LaCl isn't for everyone and I am aware of issues it can cause, but if one was inclined to use it would there be any issues in putting LaCl in the top off water so a very dilute solution of Lanthanum was added over the course of 24 hr?

The ato water can be added pre skimmer, and the amount of LaCl added via evaporation replacement would be only a small amount to slowly bring phosphate down over several days.

 

[Randy Holmes-Farley Verified Community Expert]

That's a fine way to dose it.

 

[SDReefer]

What are the benefits of dosing Lanthanum?

 

[Jlentz]

That's a fine way to dose it.

I'd not thought about this. How would one go about mixing the solution?

Would it need to be dropped into a filter sock?

 

[LobsterOfJustice]

Does anyone have some links on general use of lanthanum chloride? Where do you get it?

 

[Tennsquire]

Look up Korallin PO4 minus. I would imagine there are cheaper sources available. I believe it binds phosphates and makes them easier to skim, but I'm no chemist.

 

[Jlentz]

I get it from Amazon. Pool supplies. Right now I only use it to try and leach all the dead crap out of the pukani in curing though so I don't sweat the dose too much.

 

[Reefltx]

Hey Randy, I know LaCl isn't for everyone and I am aware of issues it can cause, but if one was inclined to use it would there be any issues in putting LaCl in the top off water so a very dilute solution of Lanthanum was added over the course of 24 hr?

The ato water can be added pre skimmer, and the amount of LaCl added via evaporation replacement would be only a small amount to slowly bring phosphate down over several days.

Never thought about that, let me know if it works. My ATO line is in my drain chamber, then the water goes through filter socks/skimmer/return.

What are the benefits of dosing Lanthanum?

Drops po4 without use of GFO.

Does anyone have some links on general use of lanthanum chloride? Where do you get it?

http://www.melevsreef.com/node/61

 

[hart24601]

Thanks Randy! Reefltx summed it up pretty well. I have read a lot about how lanthanum is not very effective at lower phosphate levels which I assume is because it binds with a calcium ion before phosphate, but I have not really heard any numbers about the reduction of efficiency or how low those levels are. I started with dry rock from BRS and it's been quite the battle with phosphates which I think are finally becoming manageable and I am hoping by having a little amount in my ATO it will reduce the gfo demand as I have used several containers of that just on a 60 cube over a couple months.

 

[Randy Holmes-Farley Verified Community Expert]

Lanthanum precipitates phosphate as lanthanum phosphate. It also reduces alkalinity to some extent by preipitating lanthanum carbonate.

Most of the material likely settles out unless caught in a filter sock, so remains in the system. The precipitate itself wouldn't be skimmable, but it may also bind organics to its surface and become skimmable to some extent.

Some folks report issues with lanthanum impacting fish, so it isn't a clear best choice for phosphate reduction.

 

[KJoFan]

Thanks Randy! Reefltx summed it up pretty well. I have read a lot about how lanthanum is not very effective at lower phosphate levels which I assume is because it binds with a calcium ion before phosphate, but I have not really heard any numbers about the reduction of efficiency or how low those levels are. I started with dry rock from BRS and it's been quite the battle with phosphates which I think are finally becoming manageable and I am hoping by having a little amount in my ATO it will reduce the gfo demand as I have used several containers of that just on a 60 cube over a couple months.

Do you plan to just let the skimmer skim out what it can or any plan to deal with the precipitate? Also, unless noted in the link which I didn't read yet, what will be your dose of lanthanum into the top off water? As in what ml/gal ratio?

 

[Randy Holmes-Farley Verified Community Expert]

I would adjust the dose based on the phosphate level you are maintaining.

 

[Randy Holmes-Farley Verified Community Expert]

Phosphate In The Reef Aquarium
https://www.reef2reef.com/blog/?p=3184

Soluble Metals to Bind Phosphate

There are several approaches that add soluble metals to bind and precipitate phosphate. The most popular involves adding lanthanum, which precipitates as lanthanum phosphate and/or lanthanum carbonate (which itself may contain some lanthanum phosphate). The lanthanum approach is widely used in the pool industry to reduce phosphate, and seems to often work well in aquaria. It is also very inexpensive, using products such as Seaklear (make sure it is a pure lanthanum version as mixtures with other metals also exist). Note that this method reduces alkalinity, as removing carbonate and phosphate as a lanthanum precipitate will reduce alkalinity.

One way to use it is to drip is slowly just upstream of a particulate filter to catch and remove a substantial amount of the precipitate that is formed. One drawback to the lanthanum approach is that much of the precipitated material may escape capture and simply settle out in the system somewhere. That may not be an issue, but many aquarists do not prefer to accumulate such material. A second concern is that some people have observed problematic reactions from aquarium inhabitants. While there are not a lot of such stories, it is enough for many aquarists to look for other options.

However, due to its low cost, this approach is especially well suited to outside of the tank operations, such as the removal of excess phosphate from phosphate-contaminated calcium carbonate rock that is later to be added to a reef aquarium.

Soluble iron has also been used in this way, but not nearly so often as lanthanum.

 

[KJoFan]

I would adjust the dose based on the phosphate level you are maintaining.

I guess my question would be, if adding to top off water to make a dilute solution, what do you base your amount off of? Tank volume and P level? As in, if your top off container is x # of gallons and used up in x # of days, would you add enough LaCl to bring your P level of your system down by x amount in the # of days it takes to use up your top off water?

Is that too confusing or make sense?

 

[Randy Holmes-Farley Verified Community Expert]

One gram of dry lanthanum chloride can, at most, reduce phosphate by about 390 mg. Likely less, maybe much less.

So adding one gram to 100 liters of tank water will, at most, reduce phosphate by 3.9 mg/L or 3.9 ppm.

If I were to use it, I'd start with a dose based on that reduction, and increase it over time since it likely isn't 100% efficient.

 

[hart24601]

Fyi I am only relying on my skimmer. I see white in the cup thst wasn't there before. I am also only dosing a small amount in the ato so there is no visible cloud or precipitate I can see elsewhere.

 

[Larry L]

One drawback to the lanthanum approach is that much of the precipitated material may escape capture and simply settle out in the system somewhere. That may not be an issue, but many aquarists do not prefer to accumulate such material.

Randy, when you say "many aquarists do not prefer to accumulate such material", why is that? Is it because the phosphate might be released back into the system at some point?

 

[Damien Buckley]

Correct URL (I think) for the 'problematic reactions' above link which is broke - https://www.reef2rainforest.com/201...ok-at-lanthanum-chloride-use-in-the-aquarium/

 

[Randy Holmes-Farley Verified Community Expert]

Randy, when you say "many aquarists do not prefer to accumulate such material", why is that? Is it because the phosphate might be released back into the system at some point?

That could be a concern, yes, such as when it passes through an organisms GI tract where the pH may be much lower and make it more likely to redissolve.

 

[Randy Holmes-Farley Verified Community Expert]

Correct URL (I think) for the 'problematic reactions' above link which is broke - https://www.reef2rainforest.com/201...ok-at-lanthanum-chloride-use-in-the-aquarium/

Here's an archived copy of the link I meant:

http://web.archive.org/web/20130120060811/http://www.coralmagazine-us.com/content/foiling-phosphate