Lanthanum chloride

[prostaff]

what was your phosphate reduction after bucket reactor

 

[tmz]

i've dosed sea klear for 5 days now at 10ml per day mixed with 5l of ro water, the 1st day my Po4 dropped from 0.08 to 0.06.
only thing is its not going any lower than 0.06 on the next 4 days :S

i'm using the D&D Po4 test kit and 5 micron socks for the sea klear to be dripped into.

That may best testing noise at the low level ranges or just the rate at which the tank is producing PO4. At very low ranges gfo seems to work better than LC or carbon dosing for me.

 

[Reefski's]

Daniel Knop said in the Coral Mag article the same thing about GFO working better at low PO4 levels.

 

[reefkeeper2]

i've dosed sea klear for 5 days now at 10ml per day mixed with 5l of ro water, the 1st day my Po4 dropped from 0.08 to 0.06.
only thing is its not going any lower than 0.06 on the next 4 days :S

i'm using the D&D Po4 test kit and 5 micron socks for the sea klear to be dripped into.

I think precipitate is still getting through your 5 micron sock and your test kit picks this up as measurable phosphate. I found this to be the case when I was using a sock. If your level went to zero, and then bounced back up quickly, I would say your tank is producing a lot of phosphate.

 

[slief]

I have been trying to deal with elavated levels of phosphate in my tank for the last couple months. I have been using GFO with little to no success. My tank has been up for 7 years but most of the live rock was in the tank previous to my last break down. I suspect that the Phosphates are in my rock and sand.

I have been considering treatment with Lanthanum and have some questions regarding the best application method for my system.

It seems that the 10 micron sock is the way I would go. My sump has 4 200 micron filter socks. My thought was to swap one of those with a 10 micron and dose directly into that sock. My big question is would that work or would I need to use 4 10 micron socks.

My tank is about 550G total water volume.

Also, what would you guys suggest as a starting dose? MY Phosphates are around .5 on my Elos test kit.

 

[Gary Majchrzak]

I use 5 millilitres of lanthanum chloride dissolved into 1 litre of water for treatment on my 300 gallon system.

on a 550 gallon system I'd say double my dosage (ie: 10 ml LaCl2 diluted into 2 litres of water). Four socks can possibly work better than one (more surface area) but if you dose into one sock very slowly and run a skimmer one sock should be fine. If you notice water in the display getting cloudy you should slow down the rate of dosing or hook up more than one sock.

 

[Newreeflady]

So, from what I've so far gathered (in just a few pages of reading) is that the main concerns are

1) removal via filtration and skimming of the precipitated lanthanum phosphate, and
2) reduction of alkalinity via a side reaction whereby lanthanum carbonate is produced.

Now, granted that I've only read a few of the many pages of posts, some of my questions may already be answered (feel free to point me there if so.)

On 1) What is the logic of dripping this into the drain stream? In doing this, you'll remove large aggregates quickly, but you'll also pass through a good amount that hasn't yet reacted and will do so after the filter, right?

On 2) What amount of time are you guys waiting until adding calcium after lanthanum chloride addition? I suppose one should separate calcium dosing quite a while from the lanthanum chloride addition so as to give it the most time to disperse throughout the aquarium (and hopefully react as much as possible with the phosphate!)

This looks like a great alternative to trying to squeeze 5 inches of refugium into my sump... hmmmm

Thanks!
Angela

 

[Gary Majchrzak]

1) dripping into a drain line gives more contact time to precip PO4 before it hits the mechanical filter. Dosing into a side stream would yield similar results.

2) ideally you shouldn't strive to dose LaCl2 into the display tank in order to react with PO4 there. Since LaCl2 depletes alkalinity I prefer to couple the treatments with water changes in order to bring alkalinity back up ASAP.

 

[slief]

on a 550 gallon system I'd say double my dosage (ie: 10 ml LaCl2 diluted into 2 litres of water). Four socks can possibly work better than one (more surface area) but if you dose into one sock very slowly and run a skimmer one sock should be fine. If you notice water in the display getting cloudy you should slow down the rate of dosing or hook up more than one sock.

Gary,
I read through the thread in its entirety today before posting and I was hoping you were still watching this thread and would reply. As with any thread that you have particpated in, I have found you are one of the more knowledgable people around here and I really respect and appreciate your advice! Thank you very much!

I would do all four socks and might still but some of them are a bit of a pain when they are clogged. Knowing that I would have to change them out possibly after a few hours pains me. I figure I will get a dozen socks to simplify my life. I will probably try to get an IV setup to administer the LaCl2 as it will be easier to insure a slow drip rate.

A couple things I forgot to mention about my system. I have a refugium that I setup a month ago. All of the water from the sump with my skimmer and filter socks is setup to flow through the refugium before returning to the tank. My skimmer is an Alpha 300 cone and I am sure that will be up for the task. The fuge has a trashcan lid size colong of chaeto growing in it with 2 inches of live rock mud and another 2 inches of live sand.

The system is setup with a Litermeter III doing automatic water changes of 3.5 Gallons per day or 25G per week.

Any concerns about the main sump running through the fuge during treatment? I could bypass some or all of the flow through the fuge if needed during the lanthanum treatment via open one valve and closing another. My flow into my sumps is around 4000GPH.

Also, should I increase my water change volume during the treatment? My saltwater for my auto changer is mixed using 0 PPM RODI water.

One last thought. It had crossed my mind to drip the lanthanum directly into the ozone intake on my skimmer but my concern with that was that it might cause that hard white stuff to build up on the insides of the skimmer or on the skimmers self cleaning head and wiper. Any thoughts?

 

[Gary Majchrzak]

sorry- I don't know anything about using LaCl2 with ozone.

I don't know how macroalgae in your case will be affected- our refugia are set up differently.
Although LaCl2 treatments have dropped PO4 levels significantly in my system the macroalgae in my lit refugium seem unaffected and continue to grow quite robustly. (Effluent from my calcium reactor feeds into my refugium and I'm sure that it's low pH and PO4 feeds macroalgae growth there.)
I would continue your water change schedule and see how it goes. Definitely monitor alkalinity closely- you should see it drop with the use of LaCl2.

 

[slief]

sorry- I don't know anything about using LaCl2 with ozone.

I don't know how macroalgae in your case will be affected- our refugia are set up differently.
Although LaCl2 treatments have dropped PO4 levels significantly in my system the macroalgae in my lit refugium seem unaffected and continue to grow quite robustly. (Effluent from my calcium reactor feeds into my refugium and I'm sure that it's low pH and PO4 feeds macroalgae growth there.)
I would continue your water change schedule and see how it goes. Definitely monitor alkalinity closely- you should see it drop with the use of LaCl2.

Thanks for the reply again! Just to clarify, I wasnt planning on running ozone through the skimmer. I was thinking about dosing the lanthanum through the ozone ports on the skimmer which are located on each volute of the red dragon pumps that drive my skimmer. This would be instead of dosing it into a 10 micron filter sock in the sump. My only concerns were that dosing into the skimmer would coat the skimmer with the white stuff and also if the skimmers effluent would need to be run through a sock as well. Only if this would be more efficient and practical that dosing into the filter socks.

 

[tmz]

I'm not at all sure the skimmer would take it out as well as a mechanical filter.

 

[slief]

I'm not at all sure the skimmer would take it out as well as a mechanical filter.

Good to know.

If I were to go 10 micron for all 4 socks, would I drip the lanthanum in all four socks. That would be a real pain but doable. One is much more managable though as I dont want to go to fast and I could go crazy rigging this up. Using another pump on my litermeter already crossed my mind but that could be overkill.

 

[Newreeflady]

1) dripping into a drain line gives more contact time to precip PO4 before it hits the mechanical filter. Dosing into a side stream would yield similar results.

2) ideally you shouldn't strive to dose LaCl2 into the display tank in order to react with PO4 there. Since LaCl2 depletes alkalinity I prefer to couple the treatments with water changes in order to bring alkalinity back up ASAP.

1) I'm not quite clear here. As I understood it you were dripping into the drain and catching the resulting precipitate immediately in a 10um filter bag. The flow rate is quite fast, and any unreacted LaCl2 goes thru the bag. Do you have another mechanical filter after that? Are you basically dripping slowly enough that you feel the LaCl2 has had time to react completely with PO4? How are you controlling dripping this stuff (I'm sure this one's been answered)?

Selectivity: I just browsed a study (Journal of Environmental Sciences 20(2008) 670"“674) they used a zeolite matrix with LaCl2. They flowed through a solution with:

20°C, pH 6.0, 1.5 mg/L phosphate concentration in the presence
300 mg/L potassium sulfate, calcium
bicarbonate, and sodium chloride concentrations, respec-
tively.

They found excellent selectivity for removal of phosphate under these conditions, with carbonate, sulfate and chloride adsorption following in that order. Side note: In the limit of high pH (10.5) the substrate released 90% of the phosphate that it had adsorbed. Under these conditions phosphate is in a monodentate form that does not form a lanthanum salt.

Another study found removal efficiency of less than 10% of phosphate under conditions of pH 8, and found 99% removal at ph 4. Because this stuff is cheap, the only concern this would bring is that of residual unreacted LaCl2 in the aquarium- potentially up to 90% of what you put in

side note: Also, it turns out if you can make a matrix with zeolite carrying the LaCl2, the zeolite removes ammonia (yay?)

This looks like it's gonna be big! It would be great if we could lower the pH before a LaCl2 column, then increase it again after removal of the precipitates. hmmmm.

 

[Newreeflady]

Definitely monitor alkalinity closely- you should see it drop with the use of LaCl2.

Does this create any imbalance in ions in the aquarium? If so, how much of a water change would you say is necessary after these treatments?

-A

 

[tmz]

Ionic imbalance question.

LaCl3 ,lanthanum chloride, disassociates in salt water. It becomes La+++ and Cl.

The La combines with PO4 species of phosphate forming LaPO4 a precipitant. This precipitant clouds the water and can be harmful to fish and other living things presumably via ingestion or clogging the gills.Hence the focus on filtering.

Additionaly , some of the La+++ joins up with CO3 forming lanthanum carbonate( La CO3) another precipitant. So it precipitates some CO3(carbonate) which is a key element in alkalinity thus reducing alkainity. I do not think in a practical sense this would amount to enough to be a concern in terms of ionic imbalance but with heavy dosage alkalinity should definitely be monitored and replenished if needed.

 

[slief]

Wow.. Lanthanum REALLY works! In the four hours it took to drip the solution (Per Gary's advice) of 10ml Lanthanum to 2L RODI into the a 10 micron sock in sump. My Phophates went from between .05 and .10 to right around .01 measured from the DT. I will test again tomorrow as I expect the levels to rise a bit . I am sure the phosphates are embedded in my rock and crushed coral and I will have to do some followup treatments. Needless to say, I am very impressed with the results so far! Thank you very much Gary, TMZ as well as the others that contributed to the information in this thread!

Here are the tools I used:

This is how I rigged it up.. The walls need to be finished up as I just did a major sump swap.

 

[Gary Majchrzak]

excellent!

 

[iamwrasseman]

are thoes bags 10 micron ?they look like my 100 or 200 micron bags and i have never seen any 10s so do tell where the heck do you purchase them ?

 

[Reefski's]

aquaticeco.com has all sizes.