Desorbing phosphate from sand with lanthanum.

[taricha]

I'd be interested in the behavior around the ballpark of 0.1 ppm po4 levels that are commonly used.

 

[Dan_P]

Decision time soon. Do I push this low, to see how low it can get (phos at 0.3ppm now)? Create a maintenance schedule to hold it where it is? Push it low and feed the hell out of the tank (will give me a Nitrate challenge)? Remove the bag, to see how fast phos goes back up? Decisions, decisions.

Try out 0.3 ppm several weeks while changing nothing else, not even your socks, and we can see how fast your system rebounds. It would be interesting to compare the rebound amount to the cumulative amount of phosphate added every day in food and miracle additives. If you want, I‘ll with the math.

 

[Garf]

Try out 0.3 ppm several weeks while changing nothing else, not even your socks, and we can see how fast your system rebounds. It would be interesting to compare the rebound amount to the cumulative amount of phosphate added every day in food and miracle additives. If you want, I‘ll with the math.

Couple of weeks in, and this bag of weekly regenerated sand seems to have reached the limit of its ability. Maintaining tank at 0.3ppm and requiring only 5 mls of lanthanum in the regen bucket to report a zero phos level (half the required dose than at 0.6ppm tank level, which sort of makes sense).Gonna have to get some proper aragonite (small grain) I think.
I have zero mechanical filtration and no skimmer, just 1.5% water changes and the bag o’ sand.

 

[biom]

Try out 0.3 ppm several weeks while changing nothing else, not even your socks…

Not sure how not changing his socks for several weeks can help phosphorus experiment but I know several scientists who practice this method with great success in different fields.

lol, sorry just couldn’t resist.

 

[Dan_P]

Not sure how not changing his socks for several weeks can help phosphorus experiment but I know several scientists who practice this method with great success in different fields.

lol, sorry just couldn’t resist.

I thought about other garments but decided socks were the family friendly choice I think sports, and gambling in general, practice “no sock changing” to neutralize the stochastic effect

 

[Miami Reef]

I do expect that lanthanum can bind to calcum carbonate surfaces (with or without bound phosphate exposed), and exposed lanthanum can bind some phosphate on top of it.

Can that inhibit calcification? (If the lanthanum binds on the coral skeleton?)

 

[Garf]

You might put a little in seawater just to make sure that does not facilitate desorption. I think it might.

I’ve tried this on the recent run and indeed, it does appear to have desorbed a little more than previous runs (20%). Of course my margins for testing error are huge, but that’s how it appears to me.

 

[Randy Holmes-Farley Verified Community Expert]

Can that inhibit calcification? (If the lanthanum binds on the coral skeleton?)

I don’t know. In people, taking oral lanthanum as a phosphate binder cs

I’ve tried this on the recent run and indeed, it does appear to have desorbed a little more than previous runs (20%). Of course my margins for testing error are huge, but that’s how it appears to me.

Ok, thanks.

 

[Miami Reef]

I don’t know. In people, taking oral lanthanum as a phosphate binder cs


Ok, thanks.

Cs?

 

[Randy Holmes-Farley Verified Community Expert]

Oops, it got cut off lol

Oral lanthanum results in detectable lanthanum in bones in people, but not any functional problem that I have heard of.

 

[Miami Reef]

Oops, it got cut off lol

Oral lanthanum results in detectable lanthanum in bones in people, but not any functional problem that I have heard of.

Ah. I see.

Worst case scenario, if lanthanum does inhibit calcification, is it akin to stacking Jenga blocks, where the lower levels might have lanthanum inhibiting, but once a new skeleton does form, and there isn’t any new lanthanum addition, calcification will resume normally, or maybe even higher with the new, reduced phosphate levels?

 

[Dan_P]

Couple of weeks in, and this bag of weekly regenerated sand seems to have reached the limit of its ability. Maintaining tank at 0.3ppm and requiring only 5 mls of lanthanum in the regen bucket to report a zero phos level (half the required dose than at 0.6ppm tank level, which sort of makes sense).Gonna have to get some proper aragonite (small grain) I think.
I have zero mechanical filtration and no skimmer, just 1.5% water changes and the bag o’ sand.

Does it seem that the sand will keep your system’s PO4 steady at 0.3 pp ?

 

[Muffin87]

It’s been shown the reagent of the Hanna PO4 checker brings the PO4 precipitate back into solution.
Thought this was worth mentioning since you seem to be testing samples that have been heavily reduced with lanthanum chloride.

Detecting unfiltered Lanthanum Phosphate

I am wondering about the ability to detect reacted Lanthanum Phosphate in the water column. I have a LaCl filter that removes the reacted Lanthanum by passing it through a large pleated filter, but would like to research using sequential settlement stages to remove the particulate by settlement...

www.reef2reef.com

 

[Garf]

Does it seem that the sand will keep your system’s PO4 steady at 0.3 pp ?

Yes, so far. Desorbing 1.5kgs of sand, weekly. It’s probably being fed more than the normal small aquarium however. The sand appears to regenerate within 24 hrs using lanthanum so there is scope to increase reduction, but that involves more effort and I don’t want to be messing with the bag o’ sand daily.

It’s been shown the reagent of the Hanna PO4 checker brings the PO4 precipitate back into solution.
Thought this was worth mentioning since you seem to be testing samples that have been heavily reduced with lanthanum chloride.

Detecting unfiltered Lanthanum Phosphate

I am wondering about the ability to detect reacted Lanthanum Phosphate in the water column. I have a LaCl filter that removes the reacted Lanthanum by passing it through a large pleated filter, but would like to research using sequential settlement stages to remove the particulate by settlement...

www.reef2reef.com

yeah. The bag of sand in the regeneration bucket actually does a great job of filtering the regeneration water, with no particulates visible. I rinse the bag of particulates with RODI, before it goes back in the tank. I’m using 2 bags, 1 in the regen bucket, 1 in the tank, then swap them over. I’m using API reagents in the Hanna primarily.

 

[Randy Holmes-Farley Verified Community Expert]

Ah. I see.

Worst case scenario, if lanthanum does inhibit calcification, is it akin to stacking Jenga blocks, where the lower levels might have lanthanum inhibiting, but once a new skeleton does form, and there isn’t any new lanthanum addition, calcification will resume normally, or maybe even higher with the new, reduced phosphate levels?

That sounds logical, but i do not recall seeing any data in that regard. I don't think I'd worry too much about lanthanum and corals.

 

[Garf]

So far during this test I’ve noticed a few anomalies. Firstly, when regenerating with saltwater, although a tested possible increase in efficiency, it appears not to be as effective at controlling tank phosphate. This appears to also be the case when using the same RODI regeneration water for too long. I don’t know if this is evidence that bacteria is blocking up the process but maximum effectiveness appears to be to replace the Lanthanum RODI mixture about every 3 or 4 cycles, maybe even more frequently. I’ll try replacing it every time for now and not be so lazy.

 

[Dan_P]

So far during this test I’ve noticed a few anomalies. Firstly, when regenerating with saltwater, although a tested possible increase in efficiency, it appears not to be as effective at controlling tank phosphate. This appears to also be the case when using the same RODI regeneration water for too long. I don’t know if this is evidence that bacteria is blocking up the process but maximum effectiveness appears to be to replace the Lanthanum RODI mixture about every 3 or 4 cycles, maybe even more frequently. I’ll try replacing it every time for now and not be so lazy.

To clarify, you have evidence that calcium carbonate sand used to remove phosphate from aquarium water is removing progressively less after each regeneration cycle. Yes?

 

[Garf]

To clarify, you have evidence that calcium carbonate sand used to remove phosphate from aquarium water is removing progressively less after each regeneration cycle. Yes?

When I used lanthanum and saltwater, or very old RODI with lanthanum as the regenerant that appears to be the case, yes. Lanthanum and new RODI appears to show consistent effectiveness.

 

[Garf]

Is there a chemical interaction between lanthanum and bleach? I’ve noticed several “stalling” events throughout this test that I’m putting it down to bacterial growth. I could use some new sand I suppose, but that’s not my preferred option.

 

[Dan_P]

Is there a chemical interaction between lanthanum and bleach? I’ve noticed several “stalling” events throughout this test that I’m putting it down to bacterial growth. I could use some new sand I suppose, but that’s not my preferred option.

Don’t know.