# NO3 and feeding

#### PatrikS

##### Prolific Poster
Hi again, folks!

I was wondering how much do you feed your algaetanks and how much KNO3 you dose??

In my tank - that is about 30 liters - I feed 1/3 tsp frozen food per day.

I may be wrong, but it just feels that it is not enough - I don't seem to get good growth if I don't dose KNO3 (besides feeding) at a rate of about 0,1 ml dry KNO3 per day, and even that seems to be a bit too little.

The light over my tank is a 70 w metal halide pendant with a 10K bulb.

Traces and Ca/KH/Mg are really abundant.

#### Tom Barr

##### Founder
Staff member
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

#### PatrikS

##### Prolific Poster
Thank's for taking time to reply, Tom! Good to hear that You dont think I'm crazy when I see that more dosing could be needed, thanks!

BTW, I have high Ca (more then 500 ppm), high Mg (over 1500 ppm) and over 16 dH in my tank (hard water from the tap plus this stuff in the synthetic salt). Could the aforementioned "nutrients" - Ca, Mg and KH - supress the uptake of NO3? Or maybe promote it?

What do You think?

#### Tom Barr

##### Founder
Staff member
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

#### PatrikS

##### Prolific Poster
Okay, Tom, thanks again. I will try and raise my KNO3-dosings to about 1/10 of a teaspoon. The funny thing I've noticed is a lot more bubbles in my DSB then before I started with dosings.

The hard part is to remember to focus on the plants health and don't bother about pestalgae... takes some guts and patience sometimes.

#### PatrikS

##### Prolific Poster
Almost forgot:

for hard corals it is advised to keep NO3 down, because it supresses calcification.

I guess the NO3 doesn't do that for macroalgae (decreases the rate of calcification) because macroalgae don't take in so much Ca??

#### Tom Barr

##### Founder
Staff member
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.

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

#### PatrikS

##### Prolific Poster

I experimented with doses of way over 60 ppm KNO3 and more then 5 ppm TMG in FW, with no ill effects, but with all the myths, missinformation and scary propaganda from reef folks I really became scared to dose more then just a speck of KNO3 and just a couple of drops of TMG in my saltwater tank.

And I mean I dont even have one single coral to worry about, but just thought that the nitrogen-argument about bad calcification could be applied to macroalgae as well. Thank You for clearing that out. Because I dont have Your experience and educational background I still fall into the trap that I tend to believe more what other people (reefers) say/imply then what my own eyes see.

Anyway - thanks a lot for busting some mythbubbles!!

#### Tom Barr

##### Founder
Staff member
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

#### morphriz

##### Junior Poster
Hi all,
It's strange Patrik that you argue different things in different places and that the references you yourself gave when you started your nano all point to exactly what Tom is saying here. Did you not read the references you yourself cite? Based on those references you made alot of claims on this issue. Later you backed from the cleary incorrect ones. I have seen few "reefers" dispute your theoretically sound claims. Myself and several more even back you plausible ones.

I have seen no experimental data that high levels of NO3 limit the process of calcification, and I mean the chemical process itself.

In the case of Macros the study you cited about macroalgae indicates that non calcifying macroalgae may outcompete calcifying when N and P is dosed. That again has nothing to do with the depositing of CaCO3 itself, only the relative competitiveness of the different algae.

There is however significant experimental data that points to the fact that high levels of NO3 has negative effects on the coral as a whole. Theorized by some that nitrogen is used by the coral to manage its zooxanthellae. High levels of NO3 leading to zoox. overcrowding, coral browning, and also coral bleaching, coral ejecting it's zoox.. Stressed corals calcify less. Again, no direct connection between NO3 and calcification. Also there is the theory on CO2 limitation in the coral, reducing calcification, from higher zoox. activity as in your cited article Patrik.

You have disputed this, Patrik, in the past and I have understood that you changed your mind. Do you again argue that high levels of NO3 does not affect a coral? Tom, your position?

When I discuss with other "reefers" on reef forums I argue that a higher nitrogen flux is necessary. In starved systems, heavily skimmed, that means holding a measurable nitrogen level. In "high-bio" systems, like the nanos of Lasse Forsberg or Eric Bornemans skimmerless tanks, that flux comes from organic nitrogen. Mostly from bacterial biomass. This also implies dosing may be necessary in some cases.

You have also seen me argue in many places that NO3 may have to be dosed in starved reef systems using macroalgae as the primary export. This is to offset the relatively few N export paths in comparison with P export paths. I have backed your nano experiment since it's interesting at least from this perspective.

Noone of note is disputing your sound claims or trying to stop you from carrying out your interesting experiments. Several are arguing against your clearly incorrect claims. You have also, as I interpret your results, empirically proven some of your own claims to be false. Because we do not agree with you to 100% does not mean we disagree. In fact I'm still very much interested in your experiments.
//Mattias

P.S. These where the references given by Patrik during the onset of a long debate on a swedish forum about dosing in the presence of corals.

1. Coral growth in high-nutrient, low-pH seawater: a case study of corals cultured at the Waikiki Aquarium, Honolulu, Hawaii

4. The Effect of External Nutrient Resources on the Population Dynamics of Zooxanthellae in a Reef Coral

2. Effects of Elevated Nitrogen and Phosphorus on Coral Reef Growth

1. Nitrate increases zooxanthellae population density and reduces skeletogenesis in corals

1. Nutrient-limited productivity of calcareous versus fleshy macroalgae in a eutrophic, carbonate-rich tropical marine environment

#### Tom Barr

##### Founder
Staff member
morphriz;13671 said:
I have seen no experimental data that high levels of NO3 limit the process of calcification, and I mean the chemical process itself.

I agree.

In the case of Macros the study you cited about macroalgae indicates that non calcifying macroalgae may outcompete calcifying when N and P is dosed. That again has nothing to do with the depositing of CaCO3 itself, only the relative competitiveness of the different algae.

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.

There is however significant experimental data that points to the fact that high levels of NO3 has negative effects on the coral as a whole.

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.

Theorized by some that nitrogen is used by the coral to manage its zooxanthellae. High levels of NO3 leading to zoox. overcrowding, coral browning, and also coral bleaching, coral ejecting it's zoox.. Stressed corals calcify less. Again, no direct connection between NO3 and calcification. Also there is the theory on CO2 limitation in the coral, reducing calcification, from higher zoox. activity as in your cited article Patrik.

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.

Do you again argue that high levels of NO3 does not affect a coral? Tom, your position?

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/$to run it just yet. It remains an unanswered question I like stuff like that, I get bored redoing CO2 1001 times, so I need to think about what is the next step. Fish and plant compatibilities are relatively easy to measure. Coral and macro algae combos are another ball of wax. Some are tempted to equate them, I'd caution against that. When I discuss with other "reefers" on reef forums I argue that a higher nitrogen flux is necessary. In starved systems, heavily skimmed, that means holding a measurable nitrogen level. In "high-bio" systems, like the nanos of Lasse Forsberg or Eric Bornemans skimmerless tanks, that flux comes from organic nitrogen. Mostly from bacterial biomass. This also implies dosing may be necessary in some cases. That's my arguement as well, the fraction that is used are different forms, organic vs some top off with inorganic. I've stated this with FW plants as well. I've found you simply do not get skimmate even with a well run skimmed system if you have a well run refugium. So it's the plants that strip things out of the tank, not the skimmer when both are running on the tank. At least that's what I see. No skimmate. Maybe I need a monster 500$ 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?

You have also seen me argue in many places that NO3 may have to be dosed in starved reef systems using macroalgae as the primary export. This is to offset the relatively few N export paths in comparison with P export paths.

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.

None of note is disputing your sound claims or trying to stop you from carrying out your interesting experiments. Several are arguing against your clearly incorrect claims. You have also, as I interpret your results, empirically proven some of your own claims to be false. Because we do not agree with you to 100% does not mean we disagree. In fact I'm still very much interested in your experiments.
//Mattias

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.

1. Coral growth in high-nutrient, low-pH seawater: a case study of corals cultured at the Waikiki Aquarium, Honolulu, Hawaii

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

#### Tom Barr

##### Founder
Staff member
If you get through the 1st 10 pages, let me know

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 Eutrophication/Papers/final1b.pdf

Regards,
Tom Barr

#### PatrikS

##### Prolific Poster
Hallo Morphiz, nice to see you here!

What do you mean I argue different in different places?

I haven't even touched the subject of potentionally supressed calcification by adding NO3 in macroalgae.

You are absolutly right about me arguing at first that some NO3 would not interfere with calcification in corals, I read some more studies and corrected my initial statements: that high levels of NO3 does indeed seems to interfere with coral growth, but then again, I didnt even thought about Ca in macroalgae.

I may have argued partially incorrectly about the corals initially, and some of the reefers took me for a fool (Svärd for instance), but then again - almost no one of them brought something to support their claims. Me at least was willing to learn and I read a lot. Moreover: I shared what I've read with those ppl, and I think many have learned a lot during that debate. Still I got unfriendly personal messages and phonecalls. How do You call that?

And many reefers in our forum in Sweden still believe that I wil inevetably get thread algae all over my tank that will choke everything if I continiue with NO3 additions. I even got a timeline predicted for this by some ppl: six months. I argue that it wount happen, not on my watch! Well, lets wait and see, shall we?

Anyway. I think, Mattias, that you missunderstood my previos post here. Can you point me in my latest post where I argue about corals and NO3?? I clearly said that I dont have a single coral in my tank. I only experiment with macroalgea. Point where:

PatrikS said:

I experimented with doses of way over 60 ppm KNO3 and more then 5 ppm TMG in FW, with no ill effects, but with all the myths, missinformation and scary propaganda from reef folks I really became scared to dose more then just a speck of KNO3 and just a couple of drops of TMG in my saltwater tank.

And I mean I dont even have one single coral to worry about, but just thought that the nitrogen-argument about bad calcification could be applied to macroalgae as well. Thank You for clearing that out. Because I dont have Your experience and educational background I still fall into the trap that I tend to believe more what other people (reefers) say/imply then what my own eyes see.

Anyway - thanks a lot for busting some mythbubbles!!

#### PatrikS

##### Prolific Poster
Tom Barr;13674 said:
If you get through the 1st 10 pages, let me know

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 Eutrophication/Papers/final1b.pdf

Regards,
Tom Barr

Thanks, Tom. It makes perfect sense. Halimeda, the calcareus algae, grows new leaves in my tank every other day despite the additions of KNO3. Probably not "despite", but actually "thanks to".

#### morphriz

##### Junior Poster
PatrikS;13682 said:
I may have argued partially incorrectly about the corals initially, and some of the reefers took me for a fool (Svärd for instance), but then again - almost no one of them brought something to support their claims. Me at least was willing to learn and I read a lot. Moreover: I shared what I've read with those ppl, and I think many have learned a lot during that debate. Still I got unfriendly personal messages and phonecalls. How do You call that?

I asked if you again plan to make your claims about calcification in corals under high nutrient conditions since you bring up "propaganda" and "scare tactics" of reefers. Reefers talk about reefs and reeftanks. Very few, add noone of note, argue against what you do with your macro tank. Some make bold claims that you will fail, most do not.

You started your claims by calling 20+ people with a total over 100 years of reefkeeping experience wrong. Citing articles to the left and right. Your tank crashed and we found out you didn't know the difference between uM and ppm. That tends to make people annoyed.

In the onset of your experiment you demonstated that your budget was real low. In my opinion low for an experiment on a low-tech planted. That tends to make people ignore you.

Making ironic comments in a thread where someones prised Montipora is showing tissue die-off to further your case on microalgae is bound to make people REALLY pissed at you. That coral can be worth as much as a dog, and if you make comments about someones dog when it's leg is rotting off you'll probably get one in the face.

We all start out ignorant and it's good you are willing to read, learn and experiment. But please stop acting the scientific martyr, noone is after you because you do radical stuff. They are just plain pissed at you.

I think there are to few people with your general attiude in the hobby. If you dont quit and run off you will no doubt make a great contribution. And beilive me, false martydom will make you leave by yourself.

PatrikS;13682 said:
And many reefers in our forum in Sweden still believe that I wil inevetably get thread algae all over my tank that will choke everything if I continiue with NO3 additions. I even got a timeline predicted for this by some ppl: six months. I argue that it wount happen, not on my watch! Well, lets wait and see, shall we?

Of course they are, you have not given enough information about the parameters of your tank. Again leaving some not knowing at all what you are doing with the result that they treat your tank from their generalized experience about REEF tanks. Since your tank is not a reef tank.... Well you get the picture.

The most interesting thing in you tank atm is your high levels of Ca and carbonates. At those elevated levels any organism using a proton pump to facilitate CO2 uptake may end up with CaCO3 or MgCO3 deposits on it's tissues. I dont know for sure that any macroalgae use this metod to obtain CO2 but it strikes me as a simpler, macroalge being primitive organisms, method than carbonic anhydrase.

We have lots of interesting things to discuss.
cheers
Mattias

#### morphriz

##### Junior Poster
Tom Barr;13673 said:
How high is the question.

Yes. The problem with the corals is that they are so diverse that no general claim can be made. Some can live with high inorganics some perfer low. Some corals that we keep in tanks can do well as high as 20ppm. I suspect that it has very much to do with the balance between organic and inorganic nitrogen.

I think the reason why this is so hot an issue nowadays is that there is a shift on the move in the general reefkeeping paradigm. Corals dont really like living in overskimmed tanks, thay may look fine and do ok but it's to far from their natural habitats. The level of inorganic nitrogen in tank water is a side issue in that more general debate.
cheers
Mattias

#### Tom Barr

##### Founder
Staff member
PatrikS;13685 said:
Thanks, Tom. It makes perfect sense. Halimeda, the calcareus algae, grows new leaves in my tank every other day despite the additions of KNO3. Probably not "despite", but actually "thanks to".

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

#### Tom Barr

##### Founder
Staff member
morphriz;13707 said:
Yes. The problem with the corals is that they are so diverse that no general claim can be made. Some can live with high inorganics some perfer low. Some corals that we keep in tanks can do well as high as 20ppm. I suspect that it has very much to do with the balance between organic and inorganic nitrogen.

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 think the reason why this is so hot an issue nowadays is that there is a shift on the move in the general reefkeeping paradigm. Corals dont really like living in overskimmed tanks, thay may look fine and do ok but it's to far from their natural habitats. The level of inorganic nitrogen in tank water is a side issue in that more general debate.
cheers
Mattias

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

#### PatrikS

##### Prolific Poster
morphriz;13705 said:
I asked if you again plan to make your claims about calcification in corals under high nutrient conditions since you bring up "propaganda" and "scare tactics" of reefers. Reefers talk about reefs and reeftanks. Very few, add noone of note, argue against what you do with your macro tank. Some make bold claims that you will fail, most do not.
Morphis, plz read again the posts from "reefers" making claims that it is the excess of NO3 and PO4 that causes the pestalgae. I argued that the the excess of NO3 and PO4 does not cause algae. I'm sorry that some saltfolks has egos bigger then their tanks, and that some ppl feel threatened simply by discussions.

Your tank crashed and we found out you didn't know the difference between uM and ppm. That tends to make people annoyed.

My tank didn't crash - where do you got that from?? I had a bunch of Caulerpa "go sexual" twice, but hell, it just one algae out of maybe six different kinds I have in my tank. I try something, it doesnt work, I get a bit sad, but one experience richer.

BTW: I bet more then half of the ppl on our boards dont know any difference about uM and ppm either. Its actually quite few that know that, the vast majority doesnt.

In the onset of your experiment you demonstated that your budget was real low. In my opinion low for an experiment on a low-tech planted. That tends to make people ignore you.
What has my budget to do with my experiments? Of course it could be scientificly more valuable to verify everything with Hatch or LaMotte kits or something better, but why should I? I dose EI-light, do a water change, and be done with it. I am interested in the visual results, not the chemical stuff.

Making ironic comments in a thread where someones prised Montipora is showing tissue die-off to further your case on microalgae is bound to make people REALLY pissed at you. That coral can be worth as much as a dog, and if you make comments about someones dog when it's leg is rotting off you'll probably get one in the face.
The guy asked about some pestalgae on top of a coral. He asked why he gets the algae. He described his tank being run with 1 liter of rowaphos (fosfatresin). Then I put out a question: "How come that there are still algae in such a limited environment?" and put a blinking smiley at the end. My point was to show that you can't really limit pestalgae, exactly the opposite from what the majority on our forum thinks. What's wrong with that?

We all start out ignorant and it's good you are willing to read, learn and experiment. But please stop acting the scientific martyr, noone is after you because you do radical stuff. They are just plain pissed at you.

I think there are to few people with your general attiude in the hobby. If you dont quit and run off you will no doubt make a great contribution. And beilive me, false martydom will make you leave by yourself.
Morphiz, where do you get everything from - martyr?? People get pissed at me because I bring the thought that it is not the "excess" of NO3 and PO4 that per se causes the algae, but rather jumpy oxygen/CO2-levels, and ammoniumspikes. I could see almost the same picture in my saltwater tank as in my freshwater tank. I therefore argued that it is most probably the same algaetriggers in saltwater as in freshwater. And that pisses some reefers off: they go like "I've been in this hobby for yyyeears!" but can't provide good answers except the do-like-me-attityde. But I want real answers, I want to discuss stuff, to argue in how and why, but what dit I get: very hostile answers that almost always leeds to attacks on my person, not on my arguments!! I asked ppl to argue against what I write, not who I am, but still in vain!

The most interesting thing in you tank atm is your high levels of Ca and carbonates. At those elevated levels any organism using a proton pump to facilitate CO2 uptake may end up with CaCO3 or MgCO3 deposits on it's tissues. I dont know for sure that any macroalgae use this metod to obtain CO2 but it strikes me as a simpler, macroalge being primitive organisms, method than carbonic anhydrase.
What do you mean? - in layman/practical terms plz.

We have lots of interesting things to discuss.
Yes, we do, but: to my knowledge you have not got any saltwater tank yet (correct me if I'm wrong). It seems to me that you look at everything from an eagle's perspective, flying high-high above and just watching (well, and judging here and now). It would be more interesting to discuss with you if you actually tried your extensive knowledge in practice first, and then argued for one or another. And as you asked pics of my tank it would be very interesting to see pics of yours.

#### PatrikS

##### Prolific Poster
Tom Barr;13713 said:
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

Aha, I see, thanks Tom! I will try to dose for slightly more then 10 ppm (to compensate for denitrification issues). Thank you!