Charles Delbeek (N:P, Alk… )

[164644]

Hi all,
Not sure if already shared but very interesting recent presentation from Charles Delbeek.
Might answer some recent questions or doubts.

Randy,
Do you have any additional comments on it?



Cheers!

 

[Billyreef-ita]

Thanks for sharing this. Very interesting!
Waiting for Randy’s comments

 

[Randy Holmes-Farley Verified Community Expert]

Sorry, I don’t have time to watch a 51 minute video and give comments.

Are there particular comments that are of interest?

 

[Miami Reef]

Sorry, I don’t have time to watch a 51 minute and give comments.

Are there particular comments that are of interest?

Haha. I knew you’d say that. I silently followed this thread to see your response.

You prefer to get your information from reading rather than videos. I’m the same way. Much quicker, and you can skim to get the gist.

 

[Randy Holmes-Farley Verified Community Expert]

Haha. I knew you’d say that. I silently followed this thread to see your response.

You prefer to get your information from reading rather than videos. I’m the same way. Much quicker, and you can skim to get the gist.

lol

Yes, I can skim a paper in a few min and pick out what to focus on.

 

[14 foot reef]

Worked with Charles when I was operating a collecting station in Hawaii back in the late 1990's. Charles was instrumental in helping us with closed system management in Oahu.

This was a very interesting speech.

 

[Randy Holmes-Farley Verified Community Expert]

This was a very interesting speech.

What did you find interesting?

 

[14 foot reef]

The tracking of the nutrients over a long period of time and real data pointing to possible close relations of nutrient levels and coral health.

 

[Randy Holmes-Farley Verified Community Expert]

The tracking of the nutrients over a long period of time and real data pointing to possible close relations of nutrient levels and coral health.

In a tank or in the ocean?

 

[14 foot reef]

In a tank or in the ocean?

To me they seemed closely related, closed systems and the ocean, so I'd say both.

 

[Miami Reef]

real data pointing to possible close relations of nutrient levels and coral health.

I think he wants to know what the real data tested. Is there a study?

 

[14 foot reef]

I think he wants to know what the real data tested. Is there a study?

The data in the speech is a pretty good source or "Study" as it when back many many years with documented numbers.

 

[Randy Holmes-Farley Verified Community Expert]

The data in the speech is a pretty good source or "Study" as it when back many many years with documented numbers.

So the nutrient numbers and health assessments came from both the ocean and reef tanks?

Any impression on action items for hobbyists?

 

[164644]

Hello,
Charles discuss a bit about the famous N : P ratios and its caveats… but I believe that the important message is the phosphorus deficiency case being the problematic one.
Interesting part also is once Alkalinity is added to the historical data (tank related).

Ocean case in minute 32:23 - a study conducted in two islands (different level of “nutrients”).

 

[CHSUB]

awesome talk. Based on science and research, not hobby observation. Very useful and appropriate for the hobbies, worth the time to watch.

 

[Jay Hemdal Verified Community Expert]

Sorry, I don’t have time to watch a 51 minute video and give comments.

Are there particular comments that are of interest?

I agree - I hardly ever watch aquarium videos. Too much time spent on extraneous material, often too basic, etc. However, I stuck this one out because I've known Charles for a long time, I wanted to see what he's been up to.

Basically, his hypothesis is that the molar N : P ratio should be about 50:1 for corals. You can get the gist of it at the 17 minute mark.

 

[CHSUB]

I agree - I hardly ever watch aquarium videos. Too much time spent on extraneous material, often too basic, etc. However, I stuck this one out because I've known Charles for a long time, I wanted to see what he's been up to.

Basically, his hypothesis is that the molar N : P ratio should be about 50:1 for corals. You can get the gist of it at the 17 minute mark.

Maybe because we are turning into an instant gratification society? Haha

 

[twentyleagues]

I did find the video informational and actually quite interesting. As usual Im at work and it takes me time to post so yeah others have already said the stuff I am saying so.......

 

[Randy Holmes-Farley Verified Community Expert]

Ok, you folks sucked me into watching the nutrient discussion from 15 to 46 min on the video. Here are my comments:

1. I think it’s a very good discussion of the complexity of our systems and the problems making any generalizations about what is best in a reef tank. Threads like the one we had a few weeks ago on folks experiences with respect to high phosphate make this clear.

2. The ratio discussion leaves me unconvinced that ratios are a good way to consider issues. Perhaps that’s the intent, but he leaned on a ratio interpretation more often than I would have. A tank with a very high N/P showing coral issues that had nitrate over 100 ppm or phosphate less than 0.03 ppm could be a ratio issue, or it could be that those absolute values are just not in desirable ranges to begin with.

3. I buy the idea that alk can play a role and his suggested mechanisms may be all or part of the explanation.

4. The complexity of not knowing how much N corals gets from the many sources aside from nitrate greatly clouds interpretations that are extrapolated to any given reef tank. Same to a lesser extent for phosphate.

5. I still contend that all issues are minimized and ratios need not be considered if one simply targets both N and P to desirable ranges. Ratios will fail when both are too low and when both are too high. Absolute value targets will not fail.

 

[rishma]

5. I still contend that all issues are minimized and ratios need not be considered if one simply targets both N and P to desirable ranges. Ratios will fail when both are too low and when both are too high. Absolute value targets will not fail.

This has always made sense to me. I honestly don’t understand why the ratio idea is so persistent but it is interesting. The idea must be a very compelling concept, but I’m not sure why. It seems easier to have a target range for each. I suppose that does result in a ratio outcome