How fast will rock leach or bind PO4 to reach equilibrium

[BigJohnny]

Can you please describe how adding LaCl3 adds "a ton of PO4". Lanthanum is an element metal, Chlorine is an element halogen. There is no Phosphorus is LaCl3, so how does it add any PO4?

I didnt say that, you misunderstood. I said you are adding a ton of po4 WHILE your dosing lanthanum e.g. fish and/or coral foods, the po4 being released from the rock isnt the sole source of po4 increase in the water column after you've dosed LaCl.

 

[Diznaster]

I didnt say that, you misunderstood. I said you are adding a ton of po4 WHILE your dosing lanthanum e.g. fish and/or coral foods, the po4 being released from the rock isnt the sole source of po4 increase in the water column after you've dosed LaCl.

Thanks for the clarification. We are only dosing LaCl3 over a short period, and measuring almost immediately after. So the misunderstanding of WHILE dosing was interpreted as "from dosing", and not "from other sources during/after dosing". It seemed obvious to me that we would not be adding a ton of PO4 in a few hours, so I assumed the former. That is a point worth adding to the data observations. I intentionally did not feed during this period. My fish probably pooped even tough I told them not to. I'm pretty low on the bio-load spectrum though. I'm not sure if @TitanCi fed a ton of PO4 in a few hours between dosing and testing.

 

[BigJohnny]

Thanks for the clarification. We are only dosing LaCl3 over a short period, and measuring almost immediately after. So the misunderstanding of WHILE dosing was interpreted as "from dosing", and not "from other sources during/after dosing". It seemed obvious to me that we would not be adding a ton of PO4 in a few hours, so I assumed the former. That is a point worth adding to the data observations. I intentionally did not feed during this period. My fish probably pooped even tough I told them not to. I'm pretty low on the bio-load spectrum though. I'm not sure if @TitanCi fed a ton of PO4 in a few hours between dosing and testing.

Haha nope you still misunderstood. I dont mean you are adding po4 literally while you are in the act of dosing the LaCl, I mean in general while you have been dosing LaCl over time you have also been adding a ton of po4 to the system via foods. Therefore, for example, if you measure .3ppm phosphate and then dose laCl once and it measures .2ppm phosphate, but then two days later it measures .3ppm phosphate again, that doesnt necessarily mean your rock leached the additional .1ppm phosphate. It could simply be an increase from feeding, your livestocks waste, etc.

That's all I was saying. Ime new nutrient levels are not stable and will fluctuate quite a bit in both directions as you are try to bring them up or down, regardless of the means. This is because it takes time for your corals, sponges, algae, and bacterial populations to acclimate to the new environment.

 

[SeaDweller]

Thanks for the clarification. We are only dosing LaCl3 over a short period, and measuring almost immediately after. So the misunderstanding of WHILE dosing was interpreted as "from dosing", and not "from other sources during/after dosing". It seemed obvious to me that we would not be adding a ton of PO4 in a few hours, so I assumed the former. That is a point worth adding to the data observations. I intentionally did not feed during this period. My fish probably pooped even tough I told them not to. I'm pretty low on the bio-load spectrum though. I'm not sure if @TitanCi fed a ton of PO4 in a few hours between dosing and testing.

My PO4 has been hovering up to 0.10 now. I dosed some more agent green and it’s now 0.03 on salifert and I’m stopping.

 

[Diznaster]

Haha nope you still misunderstood. I dont mean you are adding po4 literally while you are in the act of dosing the LaCl, I mean in general while you have been dosing LaCl over time you have also been adding a ton of po4 to the system via foods. Therefore, for example, if you measure .3ppm phosphate and then dose laCl once and it measures .2ppm phosphate, but then two days later it measures .3ppm phosphate again, that doesnt necessarily mean your rock leached the additional .1ppm phosphate. It could simply be an increase from feeding, your livestocks waste, etc.

That's all I was saying. Ime new nutrient levels are not stable and will fluctuate quite a bit in both directions as you are try to bring them up or down, regardless of the means. This is because it takes time for your corals, sponges, algae, and bacterial populations to acclimate to the new environment.

LOL, that's exactly what I think I said after the clarification. I originally interpreted "While dosing" as 'from dosing' and the confusion was because we are testing 12-24 hours after dosing without feeding. I understand your example that a 0.1ppm increase over 2 days might be from feeding. If that was the case I would see a 1.0ppm increase over 20 days and a 2.0ppm increase after 40 days. We are talking about measuring a nearly instantaneous rebound to previous levels after dosing an amount of LaCl3 that should have brought us way below zero. From 1.0ppm to 0.1ppm and back to 0.8ppm in a day. I think you are misunderstanding that we are not in a time frame of things acclimating or adding by feeding.

My PO4 has been hovering up to 0.10 now. I dosed some more agent green and it’s now 0.03 on salifert and I’m stopping.

Good to hear, I'm also still at barely detectable after a week and have been feeding as usual.

 

[BigJohnny]

I understand your example that a 0.1ppm increase over 2 days might be from feeding. If that was the case I would see a 1.0ppm increase over 20 days and a 2.0ppm increase after 40 days.

That's not how it works. Nothing in a reef tank is linear like that, and most of your parameters are fluctuating throughout the day. I'm not saying you dont have leaching, I'm just saying it's probably not all leaching.

We are talking about measuring a nearly instantaneous rebound to previous levels after dosing an amount of LaCl3 that should have brought us way below zero.

12 hrs is not instantaneous. Also you can not accurately predict the amount of po4 removed simply by dosing a certain amount of LaCl, it is EXTREMELY variable. I know some products say that but they are wrong and are likely stating an average based on their research or the max possible. There are several factors that influence how much it binds which I'd be happy to discuss with you further but my goal initially was to calm you about a possible severe leaching scenario and prevent you from overdosing LaCl and harming livestock. We've kind of spiraled off here and it seems you've already been dosing so no worries. Hope it works out for you.