Crunching Numbers at LFS - Radion, Nitrate, Phosphate

[Dana Riddle]

Water velocity has to be considered in the mix. Phosphorous, in the low concentrations we're discussing, could certainly be limited (or not) by water motion. Mass transfer through a boundary layer is dependent upon thinning of said layer (high water motion) or thickening (low water motion) is a distinct possibility. If water velocity is so low that P mass transfer doesn't come into play, Liebig's Law of the Minimum applies (that states photosynthesis is limited by the least available nutrient.) I'm really going to have to give this some thought.

 

[TexasTodd]

Dana, your past info on flow was very interesting. Some of the best I've come across.
Thanks for all of your work.

 

[Dana Riddle]

Dana, your past info on flow was very interesting. Some of the best I've come across.
Thanks for all of your work.

Thank you! There was a great deal of nutrient mass transfer work coming out of University of Hawaii decades ago. Atkinson, I think. I'll dig those papers out. If anyone is looking for an easy answer to this puzzle, probably ain't going to happen.

 

[Dana Riddle]

LED needing higher nutrients might be totally true, however like most things in the hobby I wouldn’t take led and high nutrients as 100%. I run leds, high par 300-500 with most in that upper range, undetectable phosphates (0ppb Hanna ultra low) and just a hint of nitrate on salifert so under 1ppm for sure. I don’t have it set up anymore due to health but here was my tank running those. I know JDA wasn’t impressed by it since there were not basketball size colonies but I got sick before could really grow it out. There seem to be a lot more tanks like this one now then 5 years ago when it was running. Just my experience

Beautiful tank!

 

[Dana Riddle]

Old timers in the hobby will recall the time when lighting provided by metal halide lamps was considered a 'poison.' It would take years, along with tons of research, that would provide answers to this statement. Now that we have LEDs... here we go again... Constructive debate, especially that provided in forums such as R2R, will lead us to problems we currently face. So, let's discuss his further!

 

[hart24601]

Old timers in the hobby will recall the time when lighting provided by metal halide lamps was considered a 'poison.' It would take years, along with tons of research, that would provide answers to this statement. Now that we have LEDs... here we go again... Constructive debate, especially that provided in forums such as R2R, will lead us to problems we currently face. So, let's discuss his further!

I remember all the posts and "common wisdom" about how actinic light was totally worthless and coral would die under it! It was something talked about and pretty well accepted early 2000's maybe?

 

[Dana Riddle]

I remember all the posts and "common wisdom" about how actinic light was totally worthless and coral would die under it! It was something talked about and pretty well accepted early 2000's maybe?

Every advance in the hobby has been associated lots of debate, sometimes heated and full of vitriol. It was so bad when I wrote a positive review of the first commercially available LED array for aquaria (PFO's Solaris) that I got a sympathy note from PFO. How many times have I had to rely on a thick skin, and keep my shoulder down? LOL.

 

[jda]

I don't really remember either of those in enough quantity to worry about anything, but I did not start until 1990 and MH was pretty well established by then. Some daylight MV lamps would just baste coral and kill them and I have no idea why. The only true badness that I remember with MH is the fool who convinced some people that the glass shield was not needed on DE bulbs (mistake). UVL Super Actinic should have paved the way for anybody who had questions about actinic light and these were available when I started in 1990. In the early 2000s, you were starting to get DE light fixtures with pure actinic PCs in them and I remember no outrage around then... everybody was wanting moonlighting and actinic alone. You can find one or two people who will have an opinion about anything. The critical mass of people who now think that their best color and growth under LED is at .1-.2P and 2-10N has probably wandered into the majority... I can let a few outliers go, like we all can.

Dana - flow is the easiest thing to get right in a reef tank, IMO. Lots of people overdo it, but most are at least competent after a few months and a few coral additions. I do agree that flow matters, but for the most part, people are doing OK here, IMO... but definitely worth a look to double check any data point.

I will get a handful of nasty PMs for my posts in this thread... old timer, dinosaur, hater, etc. I mostly don't care since they don't have as much to show as I do. I consider it a weird kind of love.

 

[hart24601]

I don't really remember either of those in enough quantity to worry about anything, but I did not start until 1990 and MH was pretty well established by then. Some daylight MV lamps would just baste coral and kill them and I have no idea why. The only true badness that I remember with MH is the fool who convinced some people that the glass shield was not needed on DE bulbs (mistake). UVL Super Actinic should have paved the way for anybody who had questions about actinic light and these were available when I started in 1990. In the early 2000s, you were starting to get DE light fixtures with pure actinic PCs in them and I remember no outrage around then... everybody was wanting moonlighting and actinic alone. You can find one or two people who will have an opinion about anything. The critical mass of people who now think that their best color and growth under LED is at .1-.2P and 2-10N has probably wandered into the majority... I can let a few outliers go, like we all can.

Dana - flow is the easiest thing to get right in a reef tank, IMO. Lots of people overdo it, but most are at least competent after a few months and a few coral additions. I do agree that flow matters, but for the most part, people are doing OK here, IMO... but definitely worth a look to double check any data point.

I will get a handful of nasty PMs for my posts in this thread... old timer, dinosaur, hater, etc. I mostly don't care since they don't have as much to show as I do. I consider it a weird kind of love.

I don't ever understand why people get so upset. Give me t5, mh, led, sand, bb or any combination - I will have a nice tank with any as should anyone else. It's not that hard just takes time in the system and time for us to learn. Our tinkering and grass is always greener gets a lot of us including me from time to time. Ooooooo maybe I can change this or that and get 10% more growth... At some point your going to be giving away plenty of frags either way.

 

[Dana Riddle]

I don't really remember either of those in enough quantity to worry about anything, but I did not start until 1990 and MH was pretty well established by then. Some daylight MV lamps would just baste coral and kill them and I have no idea why. The only true badness that I remember with MH is the fool who convinced some people that the glass shield was not needed on DE bulbs (mistake). UVL Super Actinic should have paved the way for anybody who had questions about actinic light and these were available when I started in 1990. In the early 2000s, you were starting to get DE light fixtures with pure actinic PCs in them and I remember no outrage around then... everybody was wanting moonlighting and actinic alone. You can find one or two people who will have an opinion about anything. The critical mass of people who now think that their best color and growth under LED is at .1-.2P and 2-10N has probably wandered into the majority... I can let a few outliers go, like we all can.

Dana - flow is the easiest thing to get right in a reef tank, IMO. Lots of people overdo it, but most are at least competent after a few months and a few coral additions. I do agree that flow matters, but for the most part, people are doing OK here, IMO... but definitely worth a look to double check any data point.

I will get a handful of nasty PMs for my posts in this thread... old timer, dinosaur, hater, etc. I mostly don't care since they don't have as much to show as I do. I consider it a weird kind of love.

Please share. I would be surprised if you have been called anything worse than I have. But I have an open mind (as always. ) JK.

 

[jda]

Just old timer (I am barely over 40), dinosaur, hater, and stuff like that. Nothing that I can not handle. I did not grow up in the day where everybody's opinion was equal and everybody got a participation trophy so we learned how to self judge and get better or just accept that we were not as good as somebody else. This made for thick skin and the ability question ourselves from the inside.

I do truly believe that hard truths and honest criticism are a true gift from the person who gave it. Most people would rather deny one than even consider a harsh truth, let alone accept one. Those that can get further ahead in life. I always welcome these.

 

[Ferrell]

Excellent info Dana.
Thanks for all the time and effort you put into the hobby and the information you share. Much appreciated

 

[Dana Riddle]

Excellent info Dana.
Thanks for all the time and effort you put into the hobby and the information you share. Much appreciated

Thank you!

 

[jda]

For reference, here is a thread of people who have to keep LEDs low or keep N and P up to keep corals from suffering... probably a lot of anecdotes here, but after a while and with enough of them, anecdotes become more than that...

https://www.reef2reef.com/threads/no3-and-po4-and-its-relationship-to-lighting.625594/

 

[Superlightman]

Any news?