Acceptable phosphate

Elricsfate

Elricsfate

New member
I am in the process of preparing to move the few coral frags I have into a smaller tank to grow them out in a more controllable environment. I'm trying to get a handle on water parameters.

I believe I understand what levels I am shooting for with regard to everything but phosphate. My frags are mushrooms, palys, gsp and xenia. I read where people say "low" levels of phosphate are okay (or even preferable) with these types of corals. But I haven't seen "low" defined.

I am waiting on the Hanna 713 to arrive as my Red Sea test kit is a bit difficult to differentiate. Right now the phosphate level is either 0.16 or 0.08 (not a lot of difference in the colors). Is that "low", or should it be even lower?

Also have GFO on the way. I just want to know what I'm shooting for.
 
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Now I'm confused. The Hanna 713 shows 0.50 ppm The Red Sea kit showed 0.08-0.16

There's a fairly large gap there...

Can anyone help me interpret these results?
 
I ordered some for the Hanna from BRS this morning. Though I would lean toward having more confidence in the Hanna than the Red Sea.

One thing is for sure...there is algae all over my tank. So I definitely have PO4 in there. The question is, how much? And, from where?
 
.005 to .03ppm

From here
http://reefkeeping.com/issues/2004-05/rhf/

Phosphate can also be a limiting nutrient for algae growth. If phosphate is allowed to accumulate, algae growth may become problematic. At concentrations below about 0.03 ppm, the growth rate of many species of phytoplankton depends on the phosphate concentration (assuming that something else is not limiting growth, such as nitrogen or iron). Above this level, the growth rate of many of the ocean's organisms is independent of phosphate concentration (although this relationship is more complicated in a reef aquarium containing iron and/or nitrogen sources such as nitrate above natural levels). So deterring algae growth by controlling phosphate requires keeping phosphate levels quite low.

For these reasons, phosphate should be kept below 0.03 ppm. Whether keeping it below 0.01 ppm will yield substantial additional benefits remains to be established, but that is a goal that some aquarists are pursuing with various ways of exporting phosphate.
Click to expand...
 
For starters quotes by two of the formost researchers on reefs are very telling:
"Our crystal clear aquaria do not come close to the nutrient loads that swirl around natural reefs. And so when we create low-nutrient water conditions, we still have to deal with the rest of a much more complex puzzle. Much like those who run their aquarium water temperature close to the thermal maximums of corals walk a narrow tight rope, I can't help but think that low-nutrient aquariums may be headed down a similar path." Charles Delbeck, Coral Nov/Dec 2010, pg 127

"Imported nutrients are usually transported to reefs from rivers; but if there are no rivers, as with reefs remote from land masses, nutrients can only come from surface ocean circulation. Often this supply is poor, and thus the vast ocean expanses have been refered to as "nutrient deserts". The Indo-Pacific has many huge atolls in these supposed deserts which testify to the resilience of reefs, but the corals themselves may lack the lush appearance of those of more fertile waters. Many reefs have another major supply of inorganic nutrients as, under certain conditions, surface currents moving against a reef face may cause deep ocean water to be drawn to the surface. This "upwelled" water is often rich in phosphorus [2.0 mg/l] and other essential chemicals." J. E. N. Veron "Corals of Austrailia and the Indo-Pacific" pg 30

If you look at the distribution of PO4 in the ocean it goes from 2 mg/l below 1000' to levels as high as ~.7 mg/l away from reefs to an average of .13 mg/l on reefs. Only a tiny fraction of reefs have PO4 levels below .05. As phosphate is a limiting nutrient for corals to use nitrogen (not just nitrate) it seems obvious to me the drop in PO4 is because the corals are sucking it up. Over the decades I have found very little correlation between PO4 and niuisance algae. Helping local aquarists deal with their hair algae issues over the decades what I have seen is either no change in PO4/nitrate levels or an INCREASE in PO4/nitrate levels as the nuisance algae dissapears. Here's a video by Richard Ross who manages the Steinhart Aquarium in CA:
https://www.youtube.com/watch?v=ZRIKW-9d2xI
 
Timfish said:
For starters quotes by two of the formost researchers on reefs are very telling:
"Our crystal clear aquaria do not come close to the nutrient loads that swirl around natural reefs. And so when we create low-nutrient water conditions, we still have to deal with the rest of a much more complex puzzle. Much like those who run their aquarium water temperature close to the thermal maximums of corals walk a narrow tight rope, I can't help but think that low-nutrient aquariums may be headed down a similar path." Charles Delbeck, Coral Nov/Dec 2010, pg 127

"Imported nutrients are usually transported to reefs from rivers; but if there are no rivers, as with reefs remote from land masses, nutrients can only come from surface ocean circulation. Often this supply is poor, and thus the vast ocean expanses have been refered to as "nutrient deserts". The Indo-Pacific has many huge atolls in these supposed deserts which testify to the resilience of reefs, but the corals themselves may lack the lush appearance of those of more fertile waters. Many reefs have another major supply of inorganic nutrients as, under certain conditions, surface currents moving against a reef face may cause deep ocean water to be drawn to the surface. This "upwelled" water is often rich in phosphorus [2.0 mg/l] and other essential chemicals." J. E. N. Veron "Corals of Austrailia and the Indo-Pacific" pg 30

If you look at the distribution of PO4 in the ocean it goes from 2 mg/l below 1000' to levels as high as ~.7 mg/l away from reefs to an average of .13 mg/l on reefs. Only a tiny fraction of reefs have PO4 levels below .05. As phosphate is a limiting nutrient for corals to use nitrogen (not just nitrate) it seems obvious to me the drop in PO4 is because the corals are sucking it up. Over the decades I have found very little correlation between PO4 and niuisance algae. Helping local aquarists deal with their hair algae issues over the decades what I have seen is either no change in PO4/nitrate levels or an INCREASE in PO4/nitrate levels as the nuisance algae dissapears. Here's a video by Richard Ross who manages the Steinhart Aquarium in CA:
https://www.youtube.com/watch?v=ZRIKW-9d2xI
Click to expand...

This is interesting, and certainly seems to be contrary to what the conventional wisdom expressed here (and elsewhere) is regarding nutrient levels and algae.

Which leaves me with two questions.

If it isn't phosphate leading to nuisance algae growth in your experience, what is it? And how do you/have you controlled it?
 
Elricsfate said:
If it isn't phosphate leading to nuisance algae growth in your experience, what is it? And how do you/have you controlled it?
Click to expand...

Its nitrate IMO...
And I've seen first hand what happens in the saltwater springs in florida when nitrate levels rise (due to farming/fertilizer/manure),etc..
I was snorkling in 10" long hair algae blowing in the currents like Trumps hair piece covering the bottom for as far as you can see (really kind of gross looking).. They had the charts/plots showing the increase in nitrogen and the algae increase followed that exactly. And it was only an increase from .6mg/L to 1mg/L (.6ppm to 1ppm nitrate) . The spring I was in was an increase from .1mg/L to .6mg/L (over a 20 year span) Those levels are over 1mg/L now and its a green hairy mess..
Phosphate levels were fairly flat lined..

And while Tim always posts that same information I'm not sure its far at all to compare the ocean with a fish tank or to say that because its like that in the ocean it should be the same in a fish tank.. (I don't think he is saying that either but just posting the information for reference) Not sure he has posted the nutrient levels he maintains in his tanks either.. I thought he is skimmerless too..
Many here have seen what happens when we have "higher" nutrient levels.. And its almost never good..
 
In the video posted by Tim, the gentleman giving the lecture works in the public aquarium plus maintains his own tanks at home. He showed that his Phosphates have been as high as 2+. yes whole number there and nitrates higher than 100. This is in a reef tank, and he does not have growth issues, or stunted growth. He gave a lot of good info in the video about phosphates, nitrates, etc. It was a worthwhile 30 minute lecture.
Basically in the end, he says we really don't know enough to say they are bad or good or whatever, but it's obvious that the belief phosphates are bad are not based on actual scientific method, as more recent papers regarding the subject contradict a popular one produced (I think it was the 70's).
 
Elricsfate said:
Now I'm confused. The Hanna 713 shows 0.50 ppm The Red Sea kit showed 0.08-0.16

There's a fairly large gap there...

Can anyone help me interpret these results?
Click to expand...

i had the similar thing happen with my checker and salifert test.

checker read 2.06
salifert read .5

big difference right. well it seems the salifert didnt really distinguish very well over .5.
maybe its what is happening with the red sea. but i dont know too much about that test kit

what levels to keep phosphates can be debated. truth is there really isnt much scientific experiments with different phosphate levels and many different corals. few out there,, but most only have 1 or 2 corals.
so to answer your question phosphates basically slows down calcification in stony corals and can provide nutrients to nuisance algae
since your keeping softies i wouldn't worry to much about phosphates in your tank, i would personally just keep on eye on my algae, if its under control i think it doesn't really matter what level you keep it at.
 
CrayolaViolence said:
In the video posted by Tim, the gentleman giving the lecture works in the public aquarium plus maintains his own tanks at home. He showed that his Phosphates have been as high as 2+. yes whole number there and nitrates higher than 100. This is in a reef tank, and he does not have growth issues, or stunted growth. He gave a lot of good info in the video about phosphates, nitrates, etc. It was a worthwhile 30 minute lecture.
Basically in the end, he says we really don't know enough to say they are bad or good or whatever, but it's obvious that the belief phosphates are bad are not based on actual scientific method, as more recent papers regarding the subject contradict a popular one produced (I think it was the 70's).
Click to expand...

Okay, so it should be obvious I'm fairly new to all of this. I find all the information interesting, but also a bit confusing.

I know I need to keep nitrate down. As best I can tell that isn't even a discussion. But it also appears to me that when I see pics of people's tanks, and those tanks are amazing, they are also maintaining very low phosphates as well. In fact, it seems that I recall reading that the three things algae needs to grow is light, nitrates, and phosphates. So if the folks with stunning tanks are incorrectly surmising that low phosphate and nitrate are what allows them to keep them amazing...to what do you attribute their success?

I totally agree with letting the tank tell the story and not chasing a number if everything is doing well...but everything isn't doing well.

The simple fact is I fell for the trap lots of newbies fall for. I started out with the idea of a FOWLR tank, and then I walked into a store that sold corals. At which point I wound up with bright lights, and other pieces of equipment I hadn't planned to get right away. Before long the whole thing was rolling down hill and picking up speed, and I started throwing money at it. And now...the budget isn't trying to hear that any more.

So let me take a moment to explain what I am dealing with, and perhaps one or more of you fine people can help me work out the way forward is.

I have a 180 with 6-8 soft coral or LPS frags in it. Including GSP, Xenia, mushrooms, 1 paly, and 1 Aquacultured Purple Stylophora Coral. (Doesn't seem like that last one was a wise choice) Until a few days ago it was overgrown with algae. I stopped feeding the tangs for a day or so, and added two urchins, and I am starting to see substantial portions of white rock again.

I also setup a 75, with just 2 dwarf angels and a damsel in it. That tank has relatively low intensity lighting, and while it does have a smattering of green and brown on the rock, it is a relatively carefree setup. It is more like a coloration on the rock than actual growth (the angels pick all day long)

Lastly, I just setup a 20g. I am going to move my frags into it so I can more easily, and inexpensively gain experience in controlling parameters and growing out frags.

My issue is, I do not want to battle the algae in the 20 like I have been in the 180. So I'm trying to get an idea of where I want the parameters to be in order to not have the issue in the first place.

Interestingly...having just gotten my new Hanna phosphate kit, I tested ALL of my water. Tap, RODI, and two of the tanks. In that process I uncovered some things I need to address, some of which are outside the scope of this thread.

Tap-0.05
RODI 0.02
180 (after a couple of weeks running phosguard) 0
20-.5

75 didn't really matter, as only a couple of fish in there and no issues.

So what it boils down to in practical reality is...do I need to do anything with the 20 before I move the corals...or is .5 okay?

I will also say, if the kit is correct, testing the 180 at 0, while there's algae all over the rocks...was a surprise. Though a test done just now (between this sentence and the last) shows NO3 at 5.
 
Elricsfate said:
Okay, so it should be obvious I'm fairly new to all of this. I find all the information interesting, but also a bit confusing.

I know I need to keep nitrate down. As best I can tell that isn't even a discussion. But it also appears to me that when I see pics of people's tanks, and those tanks are amazing, they are also maintaining very low phosphates as well. In fact, it seems that I recall reading that the three things algae needs to grow is light, nitrates, and phosphates. So if the folks with stunning tanks are incorrectly surmising that low phosphate and nitrate are what allows them to keep them amazing...to what do you attribute their success?
Click to expand...

Watch the video. It's really educational. But the short version is, we really don't know what makes or breaks a tank overall.
 
Recommend outfitting your sump for algae to grow there; light it up off hours/red light spectrum via several 1W/Each LEDs/14 hours a day minimum. Do it opposite your display to help your pH swing at night.
 
Elricsfate said:
. . . If it isn't phosphate leading to nuisance algae growth in your experience, what is it? And how do you/have you controlled it?
Click to expand...

It's the equilibrium of the ecosystem. Forest Rohwer goes into a little better explanation in his book "Coral Reefs in the Microbial Seas", the ebook version is $10. Nilsen and Fossa in the first volume of their series "The Modern Coral Reef Aquarium" point out nuisance algae is a normal part of the cycling of a reef ecosystem and will dissapear on it's own. Here's a timeline video of one of my systems which helps show the process:
https://www.youtube.com/watch?v=UjMFWHC4uBM

What's sad is if you look through the threads of people having nuisance algae problems you find lots with algae problems even after wasting lots of time and money to reduce their nitrate and PO4 to very low levels. Several things seem to me to have been overlooked. One is we can't test for organic forms of nitrogen and phosphate. Another is corals need phosphate and nitrogen as badly as algae and both algae and corals are pulling ammonia excreted by fish directly from the water. Phosphate is the limiting nutrient for corals to utilize inorganic nitrogen.

The basic assumption has been excess nitrate and excess PO4 = coral problems. That is valid, you can dump in too much food and it will cause problems but we can insure algae problems will persist by ignoring the nutritional needs of our corals and starving them. So it is possible to have gorgeous reef systems that test very, very low for nitrate and PO4 IF the system is processing an adequite amount of nitrogen and phosphate for the corals. When we start to look closer it how reef ecosystems work it gets more complex and we have to stop thinking of it as just nitrate and PO4. For starters we need to start thinking in terms of total nitrogen (organic and inorganic) and total phosphate (organic and inorganic). Then when we look at the roles of DOC and how the various forms released by corals and algae differentially alter the microbial populations we start getting a much better understanding of how our systems work. Unfortunately we've also gone way beyond what we as aquarists can test for.
 
mcgyvr said:
Its nitrate IMO...
And I've seen first hand what happens in the saltwater springs in florida when nitrate levels rise (due to farming/fertilizer/manure),etc..
I was snorkling in 10" long hair algae blowing in the currents like Trumps hair piece covering the bottom for as far as you can see (really kind of gross looking).. They had the charts/plots showing the increase in nitrogen and the algae increase followed that exactly. And it was only an increase from .6mg/L to 1mg/L (.6ppm to 1ppm nitrate) . The spring I was in was an increase from .1mg/L to .6mg/L (over a 20 year span) Those levels are over 1mg/L now and its a green hairy mess..
Phosphate levels were fairly flat lined..
Click to expand...

I'm not surprised at all with the algae problems being caused by nitrogen in springs. When there's an increase in available nutrients algae is always the first respond. If there is not an increase in either the herbivores that control the algae or plants or corals that compete with the algae for the nutrients the algae wins. This is something I've seen time and again in my reef systems.

mcgyvr said:
And while Tim always posts that same information I'm not sure its far at all to compare the ocean with a fish tank or to say that because its like that in the ocean it should be the same in a fish tank.. (I don't think he is saying that either but just posting the information for reference) Not sure he has posted the nutrient levels he maintains in his tanks either.. I thought he is skimmerless too..
Many here have seen what happens when we have "higher" nutrient levels.. And its almost never good..
Click to expand...

I make a point of posting what's found in the ocean because there's badly mistaken assumption that reefs have PO4 levels below .05 or .03 mg/l. I see repeatedly people with algae issues that do not go away with aggressively removing PO4 because of this misunderstanding of how reef ecosystems process nutrients.

I've posted the water parameters of one of my systems in my thread here:
http://reefcentral.com/forums/showthread.php?t=2601390&highlight=skimmerless

And while I do not worry about PO4 levels as high as 5 mg/l if any body asks I'll say a target PO4 number is .13 mg/l, the average found on reefs.

Nitrate is a non issue. Typically my systems almost always have very low to undetectable levels but even when I've seen spikes above 100 mg/l after a move or when remediating an algae problem there's not been an associated increase in the nuisance algae the occasions I've monitored it in my systems and it invariably corrects without me doing anything beyond adding more corals.

For the record I also do not recommend calcium below 360 mg/l. Magnesium below 1200 mg/l or alkalinity below 7 dKH.

Now before you call me a hypocrite for not following my own advice I'll point out this system and others are some of the reasons I'm certain skimmerless systems are more resilient.
 
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Some good reading here, I had high p04 with no issues, recently swapped tanks 54 corner to a 92 corner,
Arranged my rock for better flow and po4 went down, gonna add an mp10 in back bottom of tank to help increase flow, corner tanks seem to have a dead spot , when maximizing live rock quantities
 
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