Lanthanum chloride help needed weird things...


New member
Hey I am having some weird issues regarding lanthanum chloride.

I've been using lanthanum chloride for 2 weeks. Tropic Marin

I'm trying to get my phosphates down to .1 ppm they are at .4 or .5 ppm regularly

I am dripping with an IV bag 1200ml of rodi water and 15ml of lanthanum chloride. At the rate of 1 drop per second. Slowly to the aquarium into a 5 micron sock.

This is the weird part. I am using the hanna checker ulm phosphate ppm checker. Before 15ml of lanthanum phosphates at .18 16 hours later my test says .50 Why would my phosphates go up after dosing the lanthanum??? This has been tested several times with the same result the p04 goes up..

Idk why my phosphates won't go down to .1 I have been dosing lanthanum for 2 weeks now.

I have a 6 stage ro/di filter
I have a 120g with 40g sump
N03 is at 20ppm
P04 ~.4
Silicates 20ppm ( to out compete dinos with diatoms)
I run carbon through gfo reactor
I have a 25w uv sterilizer
I run tunze 9415 skimmer
4 t5s and 2 kessil 360
2 mp40s
I feed daily 2 cubes of mysis and 1 sheet of nori to about 10 fish I have and some of the fish are bigger, I rinse food in tap water in a net then feed.

Is the absorbed lanthanum with the phosphate in the sock leeching back into my water somehow? Idk I'm very confused .

Vinny Kreyling

Premium Member
My GUESS is you need a finer sock. 5 Microns is not fine enough.
10 Microns is what is recommended, but lower would also work though it might clog sooner.

Lou Ekus

Lanthanum chloride and PO4 reading

Lanthanum chloride and PO4 reading

[MENTION=225224]Gilby180[/MENTION] guess is that the crystals formed by the reaction of the PO4 and the lanthanum chloride have some effect on the optics of the Hanna checker. I seriously doubt that the actual PO4 concentration has gone up by that much. Once the PO4 is bound to the lanthanum chloride, it will not go back into solution. If it were me, I would try a PO4 reading with a standard reagent test kit and see what you get.