NO3 and feeding

The amount of dry Nitrogen from frozen foods varies considerably.

I've always been somewhat bemused that folks insist that the bioload or the food is some stable source they can measure(not you!, in general).

NH4 and total N are hard to measure what actually gets to the plant/macro or micro algae. It's hard for me to measure it.

Food can be measured for NH4, NO3 etc by dry weight. It's a bit involved, and the food itself varies batch to batch as well.

Most of the weight is water in frozen foods.
So it's not that suprising you still need more KNO3.

Regards,
Tom Barr

 

Not in marine plants really, Ca/Mg and KH are nutrients, the CO3/Ca/Mg are all needed, especially Ca and CO3.

Many macro's are mainly CaCO3 ......just like coral skeletons.......except macros assimilate and grow at least an order of magnitude faster than hard corals.

So they can pull a lot out of the water column.

Generally: Ca, CO3/KH, and NO3 and traces are the main players.

While some and myself included have added PO4, I think the systems can do quite well without dosing it as most systems are well adapted to P limitation.

Even here, I think adding say 0.1ppm PO4 from a KH2PO4 stock solution, or even 0.05ppm, 2x a week is ample along with feeding for most any tank.

IME, adding .4-.5ppm of PO4 causes some diatom blooms, but.......that was just 2 tanks, hardly a consensus and I just have not done enough dosing and measurements yet on marine macro tanks to say much.

But.........I would stick conservative abd slowly work your way up, but rather than focus on how much/diatoms etc, focus on the health of the plants.

That is the important thing/observation.

Regards,
Tom Barr

 

Why would it(NO3 at say 2-5ppm vs 10-20ppm) depress CaCO3 deposits?

I want a really good answer that's definitive before I buy that.
Why?

The macro algae have the same process..they too deposit CaCO3 into their structure.

That arguement(not directed towards you personally BTW!) about corals is nonsensical, basically a non answer.

By this arguement, we should also see issues with macro algae and more intense and faster with higher NO3 levels.
But we do not...........

I think they have other issues they have not resolved and have not dosed NO3 via KNO3 or an inorganic source.

Equating inorganic KNO3 to fish waste loading is a bad assumption, very bad.

The bubbles in the DBS: likely N2 gas, you just gave the bacteria a lot of NO3 which they like.

So some of the NO3 is being transformed rather than assimilated into plant/macro tissue.

Regards,
Tom Barr

 

Well, I am just trying to figure out why, at least in terms of CaCO3 deposition, a NO3 reading of 5ppm vs 20ppm is going to be an issue in marine tank for coral, but not Macro algae.

Simple question really.

Can the folks pushing the scare and doom reef rectify this question adequately in terms of physiology? Can they offer detailed dosing to show that this is the case with KNO3 dosing or.........not?

My guess is that most have never even heard of KNO3 dosing.
Let alone a difference between adding KNO3 vs an organic type of Nitrogen.

If they have, then they can talk about it.
If not, they truly speak based on ignorance.

Nothing wrong with being ignorant either, we all are about a great many things.

But a willingness to learn to no longer be ignorant about NO3 dosing is a good thing, simply not doing anythying test wise is, and I feel very strongly about this, a loser's arguement.

You learn nothing accepting such views.
You are expected to accept, not test and see for yourself.
Mere observation alone will only get you so far. At some point testing becomes a very effective method to learn more about things.

You need to test to see what really happens and what is really causing the probelms with the coral or with the macro algae. We all make assumptions, but some are good and some are downright bad.

Recall, many in the FW plant hobby assumed, and a few still do, that high PO4 = algae blooms.

But clearly when you are adding plenty of PO4 and have to algae, it really does not expainl things well as a model.

IME and IMO, most reef folks, like 99%, have little clue as to what specifically causes algae in their tanks.

They are not interested in inducing pest algae, but that is the only decent way to know why, at least one reason, that the pest algae appear in their tanks.

Most are unwilling, and I understand this, to trash their corals for an experiment

But with macros, they bounce back much faster, so they make a much better model to explore such issues.

Of course you need to know hwo to grow them to start with as well.

Regards,
Tom Barr

 

I agree.

I think, at least I would predict, a faster growth rate for the non CaCO3 macro.........although many can and do grow fast that have a CaCO3 deposit. Probably have to take a case by case approach for each species.

In CA, USA, we have corals as well, but not reef building to the extent of the tropical types. We have massive growth of macro algae and some corals, the issue is whether it's inorganic derived NO3 or organic, most of the kelp forest all have cooler nutrient rich water. Same with tropical diatoms.

All these are plausible hypothesis. I'm not nearly as privy to Corals as I am to plants and macros, but........I know when folks have not done experiments and what they often say and how they say it. It's as old as a broken record.

How high is the question.
I take care of reef tank, some SPS's are present, large 200 gallon tank.
Refugium, lots of Caulpera, Chaeto, various reds.

I have about 5-10ppm of NO3 on average. There is a DBS.
I dose KNO3 into the sump weekly.

I really cannot say that much because I'm not a coral nut.
I am a fish nut and macrophyte nut.
So it's a bit outside of my particular area. I keep them and have no issues with color lost etc.

I do not have a coral tank to torture and experiment with, my interest lay with macro algae and some easier corals.

I suspect most reef folks do not have a spare tank to test out whether thigns are true or not.

You need enogh control growign both the macros and corals to make a realistic go. I can do both, but I do not have the time/space/$ to run it just yet.

It remains an unanswered question
I like stuff like that, I get bored redoing CO2 1001 times, so I need to think about what is the next step.

Fish and plant compatibilities are relatively easy to measure.

Coral and macro algae combos are another ball of wax.
Some are tempted to equate them, I'd caution against that.

That's my arguement as well, the fraction that is used are different forms, organic vs some top off with inorganic.

I've stated this with FW plants as well.
I've found you simply do not get skimmate even with a well run skimmed system if you have a well run refugium.

So it's the plants that strip things out of the tank, not the skimmer when both are running on the tank. At least that's what I see.
No skimmate. Maybe I need a monster 500$ skimmer, but the Berlin Red sea thing does not make any with 500gph running through it, so what else am I to think that seems plausible?

Exactly and well said, then you have both PO4 and NO3 well balanced. I think if you drive one nutrient to a limitation, it's preferable to have it be PO4. Low NO3 as well makes things tough to grow, most plants will grow under PO4 limitatiosn much better than with low PO4.

The other issue with the recycled NH4 from within the organisms: you cannot test it for N or P, it gets used up and since it's a limiting nutrient (either of them can be) it is tough to get a handle for a test method to follow the amount of N through the system other than trace isotope fractionation.

You could never measure any NH4 but you know it's being used up rapidly without ever making it to NO3.

Also, how much is losted due to Denitrification. I really do not know for either, but there's some fairly straight forwards such as N2O measurement.

Again, nothing a hobbyists could do but something a research could rapidly figure out after a few weeks once the De NO3ers get established.

I think we all learn by making mistakes and correcting them once we know better and try to improve our knowledge base. I know many things today and would rail on myself for suggesting things I did years ago.

CO2 measure would be one, yet I was able to eye ball things well a long time ago, still, that ignorance then helped me think better today and opened up other questions.

Okay that's what I pretty much expected to hear. But I reall think there something more to this paper: stability of those nutrient levels.

We can export/import Carbon easily.
Adding marine plants provides a good source of Carbon, this means not Carbon limitation(organic carbon, not CO2, that's a whole other issue).

I think many reefer keep their systems too clean and remove all the Organioc carbon, that stresses the algae/bacteria/corals to some degree.

The system becomes increasingly more sensitive/squirrley and some reef folks resort to draconian measures to control the PO4, strip the water with skimmers etc.

So one issue makes the next even harder in terms of management and complexity as well as cost.

Why forcue natural systems to be so rigid and set them up to have issues like this? I try and be practical about this.

I need to read the rest of the papers, not just the abstracts.
But..that will have to wait till after mid terms

Regards,
Tom Barr

 

If you get through the 1st 10 pages, let me know

Nitrate corals - Google Scholar

Here's one I liked:

"Abstract
The addition of 2 mM bicarbonate to aquaria containing tropical ocean water and branches of Porites porites caused a doubling of the skeletal growth rate of the coral. Nitrate or ammonium addition (20 $\mu$M) to oligotrophic sea-water caused a significant reduction in coral growth, but when seawater containing the extra bicarbonate was supplemented with combined nitrogen, no depression of the higher growth rate was evident. We infer that (1) the present dissolved inorganic carbon (DIC) content of the ocean limits coral growth, (2) this limitation is exacerbated by nitrate and ammonium, and (3) adding DIC increases coral calcification rates and confers protection against nutrient enrichment."

Makes good sense to me.

Here's a full paper to read that:

http://www.plankton.uhh.hawaii.edu/Coastal%20Eutrophication/Papers/final1b.pdf

Regards,
Tom Barr

 

Well what does such observations imply?
Most of the white sands in Florida are not from corals, they are from Halimeda!!!
Do you think that the hard CaCO3 deposition in Halimeda might be indicative of corals as well?

The microalgae in corals are bound by different biophysical issues than the Halimeda. But near as I can tell, the 10ppm NO3 range appears pretty good for most.

Regards,
Tom Barr

 

FW and Marine plants also exists in wide ranges of environmental parameters, but..........we can find generalizable condidtions for them, simply because they exists in wide ranges in the environment, does not preclude them from having a general range for horticulture/aqua culture purposes.

Same is true for most agricultural crops, we are not reproducing nature here, we are doing horticulture, argiculture, aquaculture.

In year's past, many made this claim about many FW plants requiring wide ranges of conditions. The more I learned, the more I realized that was simply not the case.

300 species all seem to do very well.

I'm not saying it's not true with corals, but we do not know either way without doing some work and starting with a simpler system like KNO3 additions would be a good starting point.

Folks say things, but can we really show it?
You have to take risk to show that adding lots of PO4 to a planted tank works or not.

Rescuing corals from such test is not easy either, you need to be able to grow top level healthy corals, and tougher simple to grow coral would make a good model and branch out from there.

Thus one needs to be good at both macro and coral culture, not an easy requirement! Then they need to be willing to do the test and be careful.
They need $ to do this as well.

Given these requirements, the likelyhood someone will is not very high

I agree, the skimmer has limitations and folks have finally owed up to it and may focus more on macro algae.

And much like a generalize theory with FW plants: when the plants are happy, so will the fish and other critters, same is true for the marine systems.

I do think the wiggle room is much narrower in Marine systems, but there is certainly some room.

Using KNO3, and tough easy to grow coral and then going from there may be ideal. As experiences are gained, the model can be tweaked and modified to suit more species of coral and find the better macros for coral/macro systems.

Now Halophia's (Vascular angiosperms) are very nice and look good in the front foregrounds and are not like weedy macros.

Why more do not use them is beyond me.

Regards,
Tom Barr