Direct dosign of Lanthanum chloride into Skimmer using venturi

[Kurt448]

I was wondering if anyone had any comments about dosing diluted Lanthanum chloride directly into a protein skimmer via the venturi on the re-circulating skimmer pump. I am by no means a chemist and was simply wondering if this would:
1. effect the venturi by clogging it over timer
2. effect the performance of the pump over the long-run.
3. effect anything else I can't think of

Also, how quickly does the phosphate precipitate out of solution? I know that when it is used for pools it is dosed directly into the skimmer up-stream of the filtration. So would being dosed in the skimmer provide long enough of a dwell time?

Thanks in advance!

[palmerc]

I think these lanthanum based products work best if they are distributed throughout the water column as quickly as possible, so I am not a fan of adding them slowly or in isolated areas, liek a skimmer or sump.

My reason for saying this, is that lantahnum ions bind nearly just as strongly to carbonate and bicarbonates as to phosphates, so I feel that if you need to disperse the lanthanum as quickly as possible so that it has enough opportunity to bond to the phosphate, before it precipitates out as the carbonate (which is present in very high concentrations relative to phosphates).

Obviously in a swimmign pool this is slightly different as there is generally not a lot of alkalinity around to bind to the lanathanum, and also treatment dosages tend to be quite a bit higher than for aquarium usage, which will further reduce this problem.

just my thoughts.

[Randy Holmes-Farley]

I'm not a fan of using treatments that do not actually remove the phosphate from the aquarium. That said, I do not know if there is any significant chance of clogging a pump due to precipitation as I am not sure how fast it actually does precipitate from seawater.

[GTR]

At the suggestion of others I've been diluting and dosing directly in front of the skimmer pump. For months before that I was just dosing into an overflow with a filter sock in place. Seems just as effective and my basic dosage before dilution hasn't changed. I'm not sure what will happen with the skimmer pump but it's not prone to collect build up the way it's built. In two years there's never been anything to clean in it while while mag drives continue to need service every few months.

Randy, don't you think the bond is going to happen instantly regardless of what it's bonding with (PO4 or carbonates).

I know you'd rather export the PO4's but with this bond I feel pretty safe. ;) (need a crossing fingers smiley) :lol:

SteveU

[Kurt448]

Thanks all for the help. I will be testing this out next week, so I'll be sure to report back the results. FYI, I would prefer not to use this method of phosphate removal, but considering the volume of water to be treated GFO media will be too costly.

[Randy Holmes-Farley]

What volume are we talking about?

[Kurt448]

Roughly 50,000 gal. for the system we are testing this on.

[Randy Holmes-Farley]

Ah, OK.

If you haven't already, you might talk to Joe about how he doses it in diluted fashion into his million gallon aquarium:

http://reefcentral.com/forums/showthread.php?postid=9085643#post9085643

[Kurt448]

Thanks, we've been bumping emails back and forth. He's had some very impressive results.

[Randy Holmes-Farley]

:thumbsup:

Good luck. :)