Question on '0 Phosphate = Algea Consuming it'

[tutmatt3]

This isn't regarding my tank, but my mind was wondering on the thought to this theory. I'm not sure if it's a myth or a real thing, but often I've read:
~~~If you have 0 phosphate, but lots of algae, that's because your algae is consuming it at too rapid a pace before you have the ability to test it positive~~~

So my question here is: Is having 'too much phosphate' actually the problem here, or is it the result of now having too much algae consuming the phosphate too rapidly, not allowing coral the chance to use it?

Obviously one could think to 'add more phosphate' so the coral have a chance to get it, but with too much algae, it will probably get consumed before - according to what I read.

Am I understanding that correctly? Which thus leads to attempts to reduce phosphates (in order to reduce algae), to find a balance of minimal / no algae, but detectable phosphates for coral to use.


My next question would be regarding dry rock, if it leaching phosphates is another myth or factual statement. Is this covered in any of @Randy Holmes-Farley 's articles somewhere? ?

 

[Reefahholic]

This isn't regarding my tank, but my mind was wondering on the thought to this theory. I'm not sure if it's a myth or a real thing, but often I've read:
~~~If you have 0 phosphate, but lots of algae, that's because your algae is consuming it at too rapid a pace before you have the ability to test it positive~~~

So my question here is: Is having 'too much phosphate' actually the problem here, or is it the result of now having too much algae consuming the phosphate too rapidly, not allowing coral the chance to use it?

Obviously one could think to 'add more phosphate' so the coral have a chance to get it, but with too much algae, it will probably get consumed before - according to what I read.

Am I understanding that correctly? Which thus leads to attempts to reduce phosphates (in order to reduce algae), to find a balance of minimal / no algae, but detectable phosphates for coral to use.


My next question would be regarding dry rock, if it leaching phosphates is another myth or factual statement. Is this covered in any of @Randy Holmes-Farley 's articles somewhere? ?

All great questions. Let me first address your last question with what I know.

Man made dry rock and Live rock that has been dried out can both absolutely leech PO4. I've had rock leeching for months now. I bought some dry rock and since I knew it didn't have any dead organic matter on it (man made) and all the reviews I read failed to mention anything about leeching PO4...I just dumped it in my tank without thought. PO4 has been ranging 0.3 - 0.4 and as high as 0.6.

Ideal PO4 Levels are around 0.03 -0.05.

Now, does algae consume PO4 faster than we can test for it. I do think this is true, but over the years it's always been hard for me to wrap my brain around that. Having too much alage an issue? Well that depends on what kind of algae. Is it hair algae taking over your rocks or is it Cheato or Fern Culerpa down in a refugium.? The goal is to have "good" algae downstairs that will out compete "bad" algae upstairs.

Do you want reduced PO4? Short answer is yes. ZERO PO4 being good is a myth. Just like ZERO NO3 is a myth. A reef needs "some" nutrients or it will starve. I shoot for a PO4 of 0.05 and NO3 of 5.

Now, the key for algae control is to not let it get started in the first place. This means weekly testing and low PO4 and NO3. You stick with the levels I listed above and you shouldn't have issues. Once algae takes hold- it's very difficult to get rid of. However, now we have a pill now that will literally melt it away. See thread below:
http://www.marsh-reef.org/marine-an...le-pill-kills-bryopsis-its-reef-safe-too.html

So...all that being said....it's a constant balance. Happy reefing!

 

[mcarroll]

Myth and truth, but a misreading of the truth.

Zero PO4 is a bad sign. If driven too far, it can also have bad side-effects. Two different things...both true.

Bad Sign
Zero PO4 is probably a sign of a tank that has had too many nutrients added too quickly compared to what it was used to. (Eutrophication.)

An algae bloom is the natural side-effect of that situation. In fact, it's could accurately be called New Tank Syndrome, but people don't think of it that way.....even though they should.....their tank is cycling again, but the cycle is commensurate with the nutrient load....not pretty.)

If nitrates are in excess of phosphates, the algae will use up the available PO4 leaving an excess of NO3. If it starts the other way around, then you end up with an excess of PO4.

Bad Side-Effects
Driven too far with GFO and carbon dosing, zero PO4 is widely seen as a leading cause of harmful algae blooms. Dinoflagellate, Chrysophytes, Bryopsis and other outbreaks seem strongly associated, just to name a few of the more-fun potentialities.

Good read: Bacterivory in algae: A survival strategy during nutrient limitation
Good companion read: Putting the N in dinoflagellates

Myth
PO4 leaching is both. It's technically true that PO4 binds with CaCO3 and releases when dissolved levels fall.

But I haven't seen anything that suggests that leaching could be possible on the scale we see when it's blamed for algae blooms.

From what I've read so far it's mostly connected with bare CaCO3-particles in the water, not hard substrates.....which seems to make sense since substrates are mostly covered with bacterial mats or something even more substantial.

I think PO4-leaching is insignificant in the aquarium. It's certainly insignificant compared to the amount of P going into a tank daily via introduced food items.

 

[Reefahholic]

Myth and truth, but a misreading of the truth.

Zero PO4 is a bad sign. If driven too far, it can also have bad side-effects. Two different things...both true.

Bad Sign
Zero PO4 is probably a sign of a tank that has had too many nutrients added too quickly compared to what it was used to. (Eutrophication.)

An algae bloom is the natural side-effect of that situation. In fact, it's could accurately be called New Tank Syndrome, but people don't think of it that way.....even though they should.....their tank is cycling again, but the cycle is commensurate with the nutrient load....not pretty.)

If nitrates are in excess of phosphates, the algae will use up the available PO4 leaving an excess of NO3. If it starts the other way around, then you end up with an excess of PO4.

Bad Side-Effects
Driven too far with GFO and carbon dosing, zero PO4 is widely seen as a leading cause of harmful algae blooms. Dinoflagellate, Chrysophytes, Bryopsis and other outbreaks seem strongly associated, just to name a few of the more-fun potentialities.

Good read: Bacterivory in algae: A survival strategy during nutrient limitation
Good companion read: Putting the N in dinoflagellates

Myth
PO4 leaching is both. It's technically true that PO4 binds with CaCO3 and releases when dissolved levels fall.

But I haven't seen anything that suggests that leaching could be possible on the scale we see when it's blamed for algae blooms.

From what I've read so far it's mostly connected with bare CaCO3-particles in the water, not hard substrates.....which seems to make sense since substrates are mostly covered with bacterial mats or something even more substantial.

I think PO4-leaching is insignificant in the aquarium. It's certainly insignificant compared to the amount of P going into a tank daily via introduced food items.

IMO, leeching PO4 can cause algae blooms if high enough. Most leeching occurs in young tanks that can't take a punch if you will. The only problems I've had with my still elevated levels were brown coral, stunted growth, and a lot of headache. Mine ranges from 0.2 - 0.6 with 0.3- 0.4 being the average. I agree that food/feeding is a huge problem for most hobbiest. They over-feed which results in bad algae outbreaks.

Here's what leeching looks like on a graph. The following data was collected over several days pre and post Lanthanum Chloride tx's. Knocking it down one day only to see it back up the next.

 

[brandon429]

conundrum fact for reefers:

algae turf scrubber crews claim to have the best system for harvesting nutrients including phosphate. no matter who you buy the system from, they all require constant cleaning and regrowth at the binding site to work. Not any algae scrubber method is static and free from harvest as its full on mechanism, its a busy method. requisite work/export.



ff to someones reef tank with three beards of algae that have sat that way for 5 months unresponsive, and certainly not hand harvested, and now all of a sudden that commands and binds the waste from the fish and feed et al
for five mos

all the posters in the threads we can search w claim the algae is uptaking it, as efficiently as an ATS does apparently.


if a little sitting algae in a display tank was capable of uptaking all nutrients to zero, as posted, seems we could forego the busy harvest of the ATO. something is conflicting between these two instances...

lots of algae w work independent of nutrient measures too, to me that matters. to be algae free, I killed algae good thing nutrients didn't matter in my setup. I do not care what nitrate and po4 is within my reef, and that's very freeing. all I do is keep the detritus out, and apparently the measures are conducive to coral growth to the point it has to be chipped out of the tank.

 

[rog2961]

would explain why dinos get so bad at low po4 levels, looks like they are eating the bacteria holding them. Amazing

 

[mcarroll]

Here's what leeching looks like on a graph. The following data was collected over several days

Interesting numbers!

I haven't explicitly looked into this so I only know a tiny bit about it now, but I'm curious to know if there's a max amount that CaCO3 can "hold" – if this makes any sense based numbers we can find in the literature. Doesn't seem like it could, but who knows. And if it really is leaching (from PO4 bonding), then why don't people who have high PO4 spikes have rock that is "ruined" long term like this?

I've always suspected there was something else breaking down in the rock in these cases vs just "leaching".

 

[mcarroll]

if a little sitting algae in a display tank was capable of uptaking all nutrients to zero, as posted, seems we could forego the busy harvest of the ATO. something is conflicting between these two instances...

It's not so simple – that's what's conflicting. It's not algae vs nutrients. That's akin to thinking a producer is the one who makes the movie....or that the iceberg is adequately represented by the part you see floating above water. The microbial food web is (or is supposed to be) vast and algae and bacteria only make up a couple of the players, no matter how major we think their roles are. Nanoflagellates, anyone?

The other thing is a lack of recognition as to what causes/allows algae to bloom. Dissolved nutrients aren't it....they are derivative.

 

[saltyfilmfolks]

Short answer as I under stand it.
Gfo and algae strip the water of po4.
If you remove the gfo it shows the true amount of po4 in the water column that is coming off of the Rock and sand. .

 

[Reefahholic]

if a little sitting algae in a display tank was capable of uptaking all nutrients to zero, as posted, seems we could forego the busy harvest of the ATO. something is conflicting between these two instances...

This is what has tweaked my mind over the years.

 

[Reefahholic]

Short answer as I under stand it.
Gfo and algae strip the water of po4.
If you remove the gfo it shows the true amount of po4 in the water column that is coming off of the Rock and sand. .

A lot of other things consume PO4 besides GFO.

 

[Reefahholic]

Interesting numbers!

I haven't explicitly looked into this so I only know a tiny bit about it now, but I'm curious to know if there's a max amount that CaCO3 can "hold" – if this makes any sense based numbers we can find in the literature. Doesn't seem like it could, but who knows. And if it really is leaching (from PO4 bonding), then why don't people who have high PO4 spikes have rock that is "ruined" long term like this?

I've always suspected there was something else breaking down in the rock in these cases vs just "leaching".

I'm not sure, but there reason why most rocks are able to still be used and not "ruined" as you put it- is because at some point they will finally equilibrate. When the rocks leech and you remove the PO4 by binding it with GFO, LC, or harvesting with Macro's, most rocks will eventually be depleted (if you will) of all the PO4 that's bound up in the rock. Leech - Remove - Leech - Remove...until it's all gone.

I do believe it's possible that some rocks may never be able to be used again due to what is bound in the rock and how long this took place. Or at least....you probably wouldn't want to wait that long.

 

[saltyfilmfolks]

A lot of other things consume PO4 besides GFO.

It was an easy to understand example of how the water column is stripped of phosphate and giving testing error asked in the op's original post.

 

[mcarroll]

I'm not sure, but there reason why most rocks are able to still be used and not "ruined" as you put it- is because at some point they will finally equilibrate. When the rocks leech and you remove the PO4 by binding it with GFO, LC, or harvesting with Macro's, most rocks will eventually be depleted (if you will) of all the PO4 that's bound up in the rock. Leech - Remove - Leech - Remove...until it's all gone.

I do believe it's possible that some rocks may never be able to be used again due to what is bound in the rock and how long this took place. Or at least....you probably wouldn't want to wait that long.

I undersand the logic, I just don't buy that there's so much capacity. (I could be wrong.)

 

[saltyfilmfolks]

My next question would be regarding dry rock, if it leaching phosphates is another myth or factual statement. Is this covered in any of

Yes. This does happen btw.
Organic phosphates bind to our rock by thier nature. The amount will vary depending on where it came from. Some has no organics phosphates.
Once you get some dry rock you can put it in water and determine the amount and decide if or what course of action may be needed.
In used rock that is now dry it is much more common to have high phosphates bound to it.

 

[Reefahholic]

Yes. This does happen btw.
Organic phosphates bind to our rock by thier nature. The amount will vary depending on where it came from. Some has no organics phosphates.
Once you get some dry rock you can put it in water and determine the amount and decide if or what course of action may be needed.
In used rock that is now dry it is much more common to have high phosphates bound to it.

That's right. The easiest way to avoid any leeching issues is to nuke the rocks (outside the tank) in a vat. You can dose high amounts of Lanthanum Chloride which will bind the phosphate on contact and basically stop the leeching much faster. If you test zero on day one, but then 200ppb on day three- you'll know you have leeching rocks.

 

[Randy Holmes-Farley Verified Community Expert]

This isn't regarding my tank, but my mind was wondering on the thought to this theory. I'm not sure if it's a myth or a real thing, but often I've read:
~~~If you have 0 phosphate, but lots of algae, that's because your algae is consuming it at too rapid a pace before you have the ability to test it positive~~~

It's not a matter of using it too fast, it is just using it. It should not be surprising that algae can lower phosphate since turf scrubbers and macroalgae are used for that purpose.

The point is that even if the values read low, intercepting the phosphate with something like GFO will reduce the growth of algae. Low enough and it will stop it.

Phosphate being elevated does not cause algae. It simply supplies one of many things that algae MUST have to grow.

 

[tutmatt3]

Sorry for starting the thread & disappearing! Been a busy busy week.
Thanks for all the input everyone! I gave each one a read and defniitly a lot of interesting points!

It's not a matter of using it too fast, it is just using it. It should not be surprising that algae can lower phosphate since turf scrubbers and macroalgae are used for that purpose.

The point is that even if the values read low, intercepting the phosphate with something like GFO will reduce the growth of algae. Low enough and it will stop it.

Phosphate being elevated does not cause algae. It simply supplies one of many things that algae MUST have to grow.

Understood! I finally received my Hanna ULN Phosphorus checker, and got a reading of 10ppb, coming out to ~ .03ppm phosphate.

Simple tank, no GFO, no turf scrubber (not going to lie, this is the first article I've heard of it!)

Will just have to keep an eye on my levels & how my tank gets affected!!

Thanks again

 

[tutmatt3]

Sorry for starting the thread & disappearing! Been a busy busy week.
Thanks for all the input everyone! I gave each one a read and defniitly a lot of interesting points!


Understood! I finally received my Hanna ULN Phosphorus checker, and got a reading of 10ppb, coming out to ~ .03ppm phosphate.

Simple tank, no GFO, no turf scrubber (not going to lie, this is the first article I've heard of it!)

Will just have to keep an eye on my levels & how my tank gets affected!!

Thanks again

This is an old thread I know, but just wanted to follow up. My tank has always ever only been between .03-.05 (hanna ULR).
I've recently tried simplifying my tank, but remove the sponge on my HOB overflow drain, sump baffle, as well as my filter socks.
I've also turned my UV off (nothing to do w/ phosphates as far as I know, but just noting), and now my only nutrient out methods are my skimmer, and a very tiny amount of cheato which isn't really growing lol.

Tank, is still at .03 according to my tester. Cyano (i think) is still bad on the sand, and although no hair algea, I do get other types on the rock/backwall.

Being that I doubt my skimmer is removing all phosphates, and that my corals are using them all (growth is a bit limited), I'm now moving onto using PhosGaurd to reduce algae.
Feeding is 2 cubes of food a day, and somedays a bit of nori. Tank is ~85g water volume

Current attack plan is to replace it every 1 week (since its depleted fast I read) until my sand issue is resolved. Then after, I will need to find a proper ratio of how much to keep in the tank for ongoing use - while not stripping the water of ALL phos..

Will keep you guys posted, and feel free to let me know if u have any suggestions or if my plan sux. Thanks