What is missing? All-for-Reef vs changing water.

[RelaxingWithTheReef]

In my opinion it is not possible or at least it makes no sense for some elements.

Some elements, especially cobalt, but also manganese and iron are in so low concentrations in natural seawater and also the relevant concentrations in reef tanks that ICP-OES will not find them. The concentrations of all three transition metals are also very unstable and will drop drastically in between a few days after addition.

If you go into the Periodic Table of Elements in the Oceans (PTEO) and click on the elements mentioned above, you will find average residence times of 340, 60 and 200 to 500 years respectively and concentrations in the picomols/kg. You can go through all other relevant elements and find thousands, tenthousands or hundredthousands of years residence times and concentrations in the nanomolar ranges or higher.

This means that natural concentrations are very low and elements precipitate or are removed from the water very quickly. So it is not even clear which concentrations you can expect in reef tanks because the fluctuations for example due to water changes or additions will be very large.

For most other relevant elements it is better but some may still be below detection limits of ICP-OES. Fluorine is not detected by ICP-OES but by other methods.

The approach of control of every single relevant element is an illusion with the current technolgies.

Keeping Co, Mn and Fe above the detection limits of ICP-OES may already have adverse effects to corals or other tank inhabitants.

As you point out Co, Mn, and Fe levels drop drastically in a few days. What is your opinion regarding the use of higher sensitivity ICP-MS to regulate the supplementation of these three elements?

 

[Anxur]

Mi ripeterò ancora una volta, aggiungerei semplicemente il potassio direttamente al serbatoio. È economico e facile e non si esaurisce rapidamente.

Aggiungerei gli elementi del telaio agli additivi di alk e calcio. Molte persone lo fanno. Potrebbero andare bene nella nuova acqua salata, ma non vedo alcun motivo per farlo.

OK

 

[Hans-Werner]

As you point out Co, Mn, and Fe levels drop drastically in a few days. What is your opinion regarding the use of higher sensitivity ICP-MS to regulate the supplementation of these three elements?

The fluctuation will nevertheless be extreme and how do you know where you are just at the moment you take the water sample? I support the approach to dose them with other trace metals that are more stable and do not show such extreme fluctuations.

In my eyes the idea to control every single element is a bit crazy since it is neither easier nor does it have a rational background. It is kind of just another case of chasing numbers with trace metals. In fact it is even worse than other cases of chasing numbers since it is virtually impossible to really control these three elements, which with phosphate and nitrate is not the case. You can dose Co, Mn and Fe, and then? What is happening in the time until you take the next sample for ICP-MS?

 

[RelaxingWithTheReef]

The fluctuation will nevertheless be extreme and how do you know where you are just at the moment you take the water sample? I support the approach to dose them with other trace metals that are more stable and do not show such extreme fluctuations.

In my eyes the idea to control every single element is a bit crazy since it is neither easier nor does it have a rational background. It is kind of just another case of chasing numbers with trace metals. In fact it is even worse than other cases of chasing numbers since it is virtually impossible to really control these three elements, which with phosphate and nitrate is not the case. You can dose Co, Mn and Fe, and then? What is happening in the time until you take the next sample for ICP-MS?

Thank you for the reply. To be clear, I use daily dosing of Tropic Marin A and K on some of my tanks per instructions with good success. It’s proven to be an excellent product, and I recommend it to fellow reefers all the time.

As an experiment I daily dose Co, Mn, and Fe on two other tanks with the goal of matching consumption and achieving maximum short term and long term stability. If ICP-MS has no value in determining the dosage, then I’m interested to know how you would go about determining an appropriate daily dosage of these elements?

Also, how would you verify that a daily dosed all-in-one trace element package like A and K is satisfying the specific Co, Mn, and Fe needs of a tank when there can be significant variation in need and consumption between different types of tanks?

 

[Hans-Werner]

Thank you for the reply. To be clear, I use daily dosing of Tropic Marin A and K on some of my tanks per instructions with good success. It’s proven to be an excellent product, and I recommend it to fellow reefers all the time.

As an experiment I daily dose Co, Mn, and Fe on two other tanks with the goal of matching consumption and achieving maximum short term and long term stability. If ICP-MS has no value in determining the dosage, then I’m interested to know how you would go about determining an appropriate daily dosage of these elements?

Also, how would you verify that a daily dosed all-in-one trace element package like A and K is satisfying the specific Co, Mn, and Fe needs of a tank when there can be significant variation in need and consumption between different types of tanks?

I have found this out in long-term trials in reef tanks. It is quite complicated and you need much patience since all nutrients including trace elements influence each other.

First versions of the trace element supply on which the K+ and A- Elements are based where developed in an public museum and published in a German magazine in 1995/1996. At that time no one did even think about regular ICP testing.

Finally, the proof is in the pudding anyway. Who knows what an appropriate daily dosage is from theory? Mn, Fe and Co are very variable trace metals and Mn and Co have a "scavenged vertical profile" in the PTEO which means they are introduced from land by dust. I think you can imagine what that means in its dependecy from landmasses, soils on land (desert vs. rainforest) and winds blowing the dust into the sea.