Lowering PO4 using Lanthanum

[Wlachnit]

Since this has come up a fair bit recently including Rich's talk last Saturday, I thought I would post how I successfully lowered my PO4 using LaCl3.
I setup a 2 reactor system so that I could drip LaCl3 (PhosFree) using a dilute solution of it in an IV bag through the reactors to mix and catch the precipitate. At first I used GAC at the bottom of the reactor, but then found the easiest method was to use the first reactor as a mixing chamber and the BRS reactor with a sediment filter. Using the IV bag with a cannula directly into the tubing allowed me to reliably dial in how much LaCl3 I was dripping in. There are a couple different PhosFree for pools on the market. The one I used is in the pic below.

 

[rygh]

How often do you change the sediment filter?

And I guess I am curious : Adding a sediment filter will also remove a lot of detritus, which in turn will reduce phosphate.
It would be interesting to try that without the lanthanum.

 

[Coral reefer]

How long did it take to clog the sediment filter?

 

[sfsuphysics]

Man all this talk of phosphates and me seeing cyano rearing it's ugly head I decided to check and my Red Sea kit has somewhere between 0.08 to 0.12 (closer to 0.08 though), and makes me wonder if it's just a matter having a lot but the algae is sucking it out of the water faster than I can read it on a test kit.

 

[Coral reefer]

In that case I’d point out flow and lighting matter, but also if you have super low nitrate cyano can outcompete for limited nitrate.

 

[BleepBloopMunchMunch]

In that case I’d point out flow and lighting matter, but also if you have super low nitrate cyano can outcompete for limited nitrate.

What would be super low nitrate in this case?

 

[Coral reefer]

Very near zero

 

[JVU]

Unmeasurably low nitrate gives a relative advantage to Cyanobacteria because unlike almost everything else in our tanks, they are able convert (fixate) the plentiful gaseous nitrogen N2 in solution in the water to biologically-active ammonia NH3 to use. While their competitors starve.

 

[Wlachnit]

How long did it take to clog the sediment filter?

I honestly don't remember...this was a few years ago.

 

[sfsuphysics]

Unmeasurably low nitrate gives a relative advantage to Cyanobacteria because unlike almost everything else in our tanks, they are able convert (fixate) the plentiful gaseous nitrogen N2 in solution in the water to biologically-active ammonia NH3 to use. While their competitors starve.

Sounds like my issue...although this cyano bloom is relatively new, I've always had "undetectable" levels of nitrate (whether it's reality or user error I couldn't say). Could be one of those cases where dosing nitrate actually helps out a cyano issue?