Determining starting Rowaphos dosage when testing 0

[Dan_P]

I have used Rowaphos in past tanks as part of my normal maintenance using roughly 9 TBs in a 120 gallon system. My current build is testing at 5 nitrates and 0 phosphates, but I have GHA aggressively taking over the rockwork. How do you determine the starting amount of Rowaphos when you don't know your true starting phosphate values? I assume phosphates aren't truly 0....and even if they were, then using GFO wouldn't cause any issues anyways. It is a SPS tank so I obviously don't want to shock them and cause more issues but I need to get this algae under control.

I think you have an algae problem not a phosphate problem. I know hobbiest at large equate the presence of phosphate with algae growth. i would propose that hobbiest reconsider their logic.

On the reef, algae can grow in water that coral grow but algae is not to be found because of grazing. In the aquarium it is the same situation. There really isn’t a good reason to think you can control algae growth by tweaking the phosphate concentration. Algae can only be grazed or killed with algicides like Vibrant. Physical removal does not work because you cannot remove all the microscopic filaments adhering to rock surfaces. Growing coralline algae seems to work possubly because GHA cannot colonize a coralline covered surface. I propose that if there is too much GHA in your system, there isn’t enough grazing.

 

[Waters]

I think you have an algae problem not a phosphate problem. I know hobbiest at large equate the presence of phosphate with algae growth. i would propose that hobbiest reconsider their logic.

On the reef, algae can grow in water that coral grow but algae is not to be found because of grazing. In the aquarium it is the same situation. There really isn’t a good reason to think you can control algae growth by tweaking the phosphate concentration. Algae can only be grazed or killed with algicides like Vibrant. Physical removal does not work because you cannot remove all the microscopic filaments adhering to rock surfaces. Growing coralline algae seems to work possubly because GHA cannot colonize a coralline covered surface. I propose that if there is too much GHA in your system, there isn’t enough grazing.

I think this is what I am finally coming to realize with the help of this thread and talking to some other hobbyists. I think what you are saying (and others have said) is true.....my problem isn't with my nutrients.........it is with more a lack of herbivores. I have already tried vibrant with this tank and unfortunately it caused immediate issues with my acros (not due to nutrients bottoming out....I tested religiously) so I stopped after a couple of weeks. All I have left is increasing my CUC numbers which I will do asap.

 

[Big E]

There's a lot of solid advice here so I'm going to double down or maybe add at little insight-----

I know we talked about this a few days ago, but I think you're looking at this the wrong way. You have an imbalance and this species of algae is thriving at that ratio of P04 vs N03. This algae species has driven down your Po4 to zero.

Dose po4 and get your readings up to a level to at least .08 or more. I know on the surface it seems backwards thinking but it's not.

You're going to have to test daily at the same time each day to figure out your Po4 consumption but once that's nailed down you can go from there. I usually try to test a few hours after the lights come on and before I feed the fish.

Try to manually get the long strands out as snails and such aren't going to touch it when long. Get some/more astreas and there are also smaller snails, I think cerinth, that can even get into tighter spots.

I'd look into getting a cleaner package from Reef Cleaners. Get a few Money Cowries......they won't get into crevises but they do the work of many snails.

Continue the basting to keep detritus out of the rock crevices.

I know we've talked about this before when I was at your house but you do need to try to get some coraline growing on your rocks as this can help too. There's a few options..........give me a call if you want to go over this whole issue more.

 

[Randy Holmes-Farley]

There's a lot of solid advice here so I'm going to double down or maybe add at little insight-----

I know we talked about this a few days ago, but I think you're looking at this the wrong way. You have an imbalance and this species of algae is thriving at that ratio of P04 vs N03. This algae species has driven down your Po4 to zero.

Dose po4 and get your readings up to a level to at least .08 or more. I know on the surface it seems backwards thinking but it's not.

You're going to have to test daily at the same time each day to figure out your Po4 consumption but once that's nailed down you can go from there. I usually try to test a few hours after the lights come on and before I feed the fish.

Try to manually get the long strands out as snails and such aren't going to touch it when long. Get some/more astreas and there are also smaller snails, I think cerinth, that can even get into tighter spots.

I'd look into getting a cleaner package from Reef Cleaners. Get a few Money Cowries......they won't get into crevises but they do the work of many snails.

Continue the basting to keep detritus out of the rock crevices.

I know we've talked about this before when I was at your house but you do need to try to get some coraline growing on your rocks as this can help too. There's a few options..........give me a call if you want to go over this whole issue more.

FWIW, I don't accept the ratio theory that some espouse. it makes no sense to me.

I cannot see any reason that raising a nutrient level will deter a pest (like dinos or algae) unless that increase spurs something else that outcompetes the pest for space or a needed other nutrient (such as a trace element).

i think that is what happens with dinos, but I have never heard it suggested to be the case for algae.

Low phosphate with a lot of algae to me just means all that algae is taking up the nutrients, exactly as we hope it does in other settings, such as a refugium or algae reactor.

 

[Big E]

FWIW, I don't accept the ratio theory that some espouse. it makes no sense to me.

I cannot see any reason that raising a nutrient level will deter a pest (like dinos or algae) unless that increase spurs something else that outcompetes the pest for space or a needed other nutrient (such as a trace element).

i think that is what happens with dinos, but I have never heard it suggested to be the case for algae.

Low phosphate with a lot of algae to me just means all that algae is taking up the nutrients, exactly as we hope it does in other settings, such as a refugium or algae reactor.

Believe what you want, I've experienced many times what ratios work best for certain corals. It's what I have seen/ experienced, talked to other experienced acropora keepers, and data I've collected on my own.

I've also experienced the same with some algae..........some thrive and grow faster based on ratios. There is also plenty of scientific data on ratios of what some species of algae consume.

Many more coral farmers are also focusing on ratios in recent years.

 

[Randy Holmes-Farley]

Believe what you want, I've experienced many times what ratios work best for certain corals. It's what I have seen/ experienced, talked to other experienced acropora keepers, and data I've collected on my own.

I've also experienced the same with some algae..........some thrive and grow faster based on ratios. There is also plenty of scientific data on ratios of what some species of algae consume.

Many more coral farmers are also focusing on ratios in recent years.

No, you are misunderstanding the scientific literature, and also likely the effects in reef tanks. let's think this through, and don't just discard my assertion as uninformed. I assure you it is based on scientific papers, and the reading of hundreds of thousands of reefers posts over decades of being in the hobby.

Of course there are ratios of what any organism consumes. That does not say anything whatsoever about the concentrations needed in the water to support that growth. The Redfield ratio and related ratios DO NOT say anything about the effects of altering nutrient concentrations in the water. That is an entirely different experiment.

There is NO case in the scientific literature that I have ever seen of an algae where raising a nutrient makes that algae grow more slowly or not at all (unless you might boost something so incredibly high that it becomes toxic). Increasing nutrients generally makes it easier for a organism to grow (if that nutrient is a limiting factor for that organism's growth under those conditions) or it has no direct effect at all.

Not only is there no literature on it, there is no viable rationale how that would even happen. Can you suggest a reason?

If there are articles that show an algae is deterred to grow by raising nutrients (N and P), please post them.

As I noted, what does happen with some organisms (such as, IMO, dinos) is that as you raise nutrients, you make it easier for something else to grow, and that something else may outcompete the pest for space or for another limiting growth factor. Thus, one may well be able to solve a pest problem by raising nutrients. I've not seen that demonstrated for an algae in a reef tank, but it is certainly not beyond the realm of possibility.

 

[Randy Holmes-Farley]

This is the sort of study needed to assess the effects of nutrient levels on growth of organisms. In this case they did it for macroalgae.

They use the word "ratio" 14 times to discuss N ratios in the water and ratios in the tissues, but nowhere do they suggest that a certain ratio of nutrients is optimal. Growth increases are always discussed in the context that one or both is limiting growth and adding more helps growth.

Wayback Machine

"A survey of results from nutrient-enrichment experiments using coral reef macroalgae bears this out: of 36 species tested in seven studies, inorganic nitrogen enrichment enhanced growth in 22 species and inorganic phosphorus enhanced growth in 17 species"

 

[Randy Holmes-Farley]

The problem with thinking of nutrients in ratios, rather then setting optimal levels for them independently, is that it allows for clearly suboptimal situations, where setting the actual desirable levels does not.

Suppose that you think that 5 ppm nitrate and 0.03 ppm phosphate is a great set of values. Ratio is 500 nitrate to 3 phosphate. OK, so my suggestion is to set a range, say 2-10 ppm nitrate and 0.02 to 0.05 ppm phosphate around that value. Those are likely all quite good values for a reef tank. No ratios involved.

But if one only looks to ratios, that says crazy things are OK.

How about 0.000000005 ppm nitrate and 0.00000000003 ppm phosphate. Has the right ratio, so is it good to go?

What about 50,000 ppm nitrate and 300 ppm phosphate. Same perfect ratio, right? Definitely good to go!

That is the reason that I think many folks are inappropriately using things like the Redfield ratio alone to set target values, when it reality, that neither is useful nor sensible.

 

[Dan_P]

No, you are misunderstanding the scientific literature, and also likely the effects in reef tanks. let's think this through, and don't just discard my assertion as uninformed. I assure you it is based on scientific papers, and the reading of hundreds of thousands of reefers posts over decades of being in the hobby.

Of course there are ratios of what any organism consumes. That does not say anything whatsoever about the concentrations needed in the water to support that growth. The Redfield ratio and related ratios DO NOT say anything about the effects of altering nutrient concentrations in the water. That is an entirely different experiment.

There is NO case in the scientific literature that I have ever seen of an algae where raising a nutrient makes that algae grow more slowly or not at all (unless you might boost something so incredibly high that it becomes toxic). Increasing nutrients generally makes it easier for a organism to grow (if that nutrient is a limiting factor for that organism's growth under those conditions) or it has no direct effect at all.

Not only is there no literature on it, there is no viable rationale how that would even happen. Can you suggest a reason?

If there are articles that show an algae is deterred to grow by raising nutrients (N and P), please post them.

As I noted, what does happen with some organisms (such as, IMO, dinos) is that as you raise nutrients, you make it easier for something else to grow, and that something else may outcompete the pest for space or for another limiting growth factor. Thus, one may well be able to solve a pest problem by raising nutrients. I've not seen that demonstrated for an algae in a reef tank, but it is certainly not beyond the realm of possibility.

There is one idea to test out here, one that explains why raising nitrate or phosphate could cause nuisance microorganisms to recede. Here is the idea.

When photosynthetic organisms receive too much light or receive the optimum amount of light but not enough nitrogen (or phosphate), they are stressed and respond by exuding organic molecules because they cannot turn off their photosynthesis. This dissolved organic carbon enriches the surrounding water and many organisms take advantage of this with increased growth. Because of rapid dilution, this banquet is localized and explains why we often see localized outbreaks of diatoms, dinoflagellates and cyanobacteria. Since every aquarium has epilithic algae communities, I propose this is one of the major causes for nuisance microorganism growth in new aquaria when it is starved and probably all aquaria at some point in their life time when nitrogen is depleted.

That’s the notion which I will donate to this very interesting conversation. If nature is kind to me, I will have some data to support this idea, maybe by the end of the year (???)

 

[Randy Holmes-Farley]

There is one idea to test out here, one that explains why raising nitrate or phosphate could cause nuisance microorganisms to recede. Here is the idea.

When photosynthetic organisms receive too much light or receive the optimum amount of light but not enough nitrogen (or phosphate), they are stressed and respond by exuding organic molecules because they cannot turn off their photosynthesis. This dissolved organic carbon enriches the surrounding water and many organisms take advantage of this with increased growth. Because of rapid dilution, this banquet is localized and explains why we often see localized outbreaks of diatoms, dinoflagellates and cyanobacteria. Since every aquarium has epilithic algae communities, I propose this is one of the major causes for nuisance microorganism growth in new aquaria when it is starved and probably all aquaria at some point in their life time when nitrogen is depleted.

That’s the notion which I will donate to this very interesting conversation. If nature is kind to me, I will have some data to support this idea, maybe by the end of the year (???)

Something like that could certainly be happening, although I do not know that it does.

For localized growth, I'll add this from the article I posted above:

Wayback Machine

"These results suggest that, in order to persist in low-nutrient coral reef systems, some macroalgae require high rates of nutrient advection or access to benthic nutrient sources in addition to nutrients in the overlying water column. Nutrient concentrations in water samples collected from the microenvironments inhabited or created by macroalgae were compared to nutrient concentrations in the overlying water column. On protected reef flats, inorganic nitrogen concentrations within dense mats of Gracilaria salicornia and Kappaphycus alvarezii, and inorganic nitrogen and phosphate concentrations in sediment porewater near the rhizophytic algae Caulerpa racemosa and C. sertularioides were significantly higher than in the water column. The sediments associated with these mat-forming and rhizophytic species appear to function as localized nutrient sources, making sustained growth possible despite the oligotrophic water column"

 

[Dan_P]

Something like that could certainly be happening, although I do not know that it does.

For localized growth, I'll add this from the article I posted above:

Wayback Machine

"These results suggest that, in order to persist in low-nutrient coral reef systems, some macroalgae require high rates of nutrient advection or access to benthic nutrient sources in addition to nutrients in the overlying water column. Nutrient concentrations in water samples collected from the microenvironments inhabited or created by macroalgae were compared to nutrient concentrations in the overlying water column. On protected reef flats, inorganic nitrogen concentrations within dense mats of Gracilaria salicornia and Kappaphycus alvarezii, and inorganic nitrogen and phosphate concentrations in sediment porewater near the rhizophytic algae Caulerpa racemosa and C. sertularioides were significantly higher than in the water column. The sediments associated with these mat-forming and rhizophytic species appear to function as localized nutrient sources, making sustained growth possible despite the oligotrophic water column"

How about this tenet (there are more, but this one applies to our discussion):

Nuisance microorganism growth tenet 1: a high nutrient concentration is required to encourage and sustain rapid growth and high density accumulation of microorganisms.

High concentrations of nutrients in an aquarium seem to occur only at surfaces, either from bacterial action on organic matter or exudates from algae.

This tenet does not apply to invasive macro algae. In this case, the issue is more likely a lack of grazing and not excessive nutrients.

 

[Big E]

The problem with thinking of nutrients in ratios, rather then setting optimal levels for them independently, is that it allows for clearly suboptimal situations, where setting the actual desirable levels does not.

Suppose that you think that 5 ppm nitrate and 0.03 ppm phosphate is a great set of values. Ratio is 500 nitrate to 3 phosphate. OK, so my suggestion is to set a range, say 2-10 ppm nitrate and 0.02 to 0.05 ppm phosphate around that value. Those are likely all quite good values for a reef tank. No ratios involved.

But if one only looks to ratios, that says crazy things are OK.

How about 0.000000005 ppm nitrate and 0.00000000003 ppm phosphate. Has the right ratio, so is it good to go?

What about 50,000 ppm nitrate and 300 ppm phosphate. Same perfect ratio, right? Definitely good to go!

That is the reason that I think many folks are inappropriately using things like the Redfield ratio alone to set target values, when it reality, that neither is useful nor sensible.

Randy,

I never talk of the Redfield ratio

I don't think we are speaking the same language. My talk of ratios is not the same as what you as a chemist define those numbers. My approach is much different and from a simple math, statistics or analytical perspective. It's the formula I use when I speak of ratios.

I'll address some of your comments-----

"The problem with thinking of nutrients in ratios, rather then setting optimal levels for them independently, is that it allows for clearly suboptimal situations, where setting the actual desirable levels does not.

Suppose that you think that 5 ppm nitrate and 0.03 ppm phosphate is a great set of values. Ratio is 500 nitrate to 3 phosphate. OK, so my suggestion is to set a range, say 2-10 ppm nitrate and 0.02 to 0.05 ppm phosphate around that value. Those are likely all quite good values for a reef tank. No ratios involved."

Everything I talk about in range and ratios I use for acropora as they are more sensitive. Lps and softies are much more forgiving.

First off. the ratios I define have to be within the "accepted range". I only apply the ratio in the accepted range I have communicated for years.............they aren't written in stone just a guideline range

P04- .03-.10
N03- 1.0- 10.0

In your 5.0 to .03 example, which is in the suggested acceptable range, that ratio is 5.0/.03= 166.6

The ratio I suggest as optimal and most common is 100 to 1. The ratios can vary from 50-200 to 1. Usually if you are in that ratio your acropora will do well.

If you were to take nutrient numbers from a wide range of successful acropora systems the graph will come out with a bell curve. Roughly 100-1 being in that median range and most successful tanks in or around that. The fringes are out at 50 and 200.


"How about 0.000000005 ppm nitrate and 0.00000000003 ppm phosphate. Has the right ratio, so is it good to go?

What about 50,000 ppm nitrate and 300 ppm phosphate. Same perfect ratio, right? Definitely good to go!"

No, because those crazy numbers aren't in the acceptable range and results to the aquarium aren't good.

It's why I want the OP to raise his P04 as I have also seen different algae go through boom and bust stages at certain levels. Imo, all coral species and algae have optimal levels they like and when the condtions suit them they will thrive.

------------------------------------------

All the data I collect and my experiences are based on the range and ratios I have explained above.

I'd prefer not to get into rest of this as I have no desire to get into a point to point debate. I posted to help a friend out and that's it. What I suggest is from experience/observations and data I've collected on my own. I use scientific research to see if there are some 2+2=4 relationships.

I've been studying and looking at this for 15+ years and that's the formula I use when I'm talking range and ratios.

 

[Randy Holmes-Farley]

It's why I want the OP to raise his P04 as I have also seen different algae go through boom and bust stages at certain levels. Imo, all coral species and algae have optimal levels they like and when the condtions suit them they will thrive.

I certainly do not deny the possibility that raising phosphate will drive a different type of algae, possibly to the detriment of the pest by competition.

I do content that it cannot deter a single type of algae, and that idea is not supported by any data I have seen.

So perhaps the observation is fine, but the reason for it that you suggest, and maybe the action taken because of that interpretation, is what I do not agree with.

 

[jarviz]

Is it even possible to have a tank with no algae, where corals and fish are still thriving? The tank would need to be perfectly balanced and maintained and monitored super religiously. having some algae or even diatoms with a CUC that can keep up would just make it so much easier.

 

[Randy Holmes-Farley]

Is it even possible to have a tank with no algae, where corals and fish are still thriving? The tank would need to be perfectly balanced and maintained and monitored super religiously. having some algae or even diatoms with a CUC that can keep up would just make it so much easier.

having sufficient herbivores (especially fish) can make that happen.