Guess the Phosphate level

[Jstn]

Im glad i found this thread, I have a friend with high PO4, no gfo, just skimmer and monthly 30% wc in a 180 gal. His sps look great, colorful, good growth, he claimed his PO4 was high, so I took a sample and tested it. It was 0.63 ppm, I tested it twice with two different samples and got the same numbers. Meanwhile my tank look bad with 0.06 ppm, strange.

 

[Thales]

Water tests at work on Thursday. First time I had work test NO3, check out that crazy number.

Alk = 3.377
Ca = 452.4
Mg = 1337.5
NO3- = 100.7
PO43- = 1.392

Still waiting for the AWT test to come back for comparison.
I am surprised at that NO3 number and it could be something odd in the water sample or the testing, and will be able to get it retested the week after next.

The potential issues with high nitrates seem to be
- fueling algae growth
- slowing coral growth by increasing zooxanthellae depriving the coral of carbon, however higher alkalinity seems to alleviate this issue.

So, algae is not a problem in my tank, and the growth is decent. I have had some STN with 2 corals in the tank in the last few week, A. horrida and a Stylo, but I don't overly worry about one or two corals being off (especially because flow was disrupted for several weeks while trapping out fish) and the STN has slowed or stopped on both corals. Even so, that NO3 number makes me at least superstitiously nervous and I have started adding vinegar to the top off. I'll try to put up the dosage I am using as well as a current pic of the tank later tonight.

 

[reefmutt]

Crazy numbers, indeed!!!
So with the carbon dosing, what will your target numbers be?
How far will you attempt to bring down no3?
I'm curious to see where p goes with the carbon source..

 

[Dapg8gt]

Wow those are some crazy numbers. I am a big supporter of carbon dosing to keep nitrate in check with heavy feedings so I'm interested on how it does on your tank just because you are not =).

 

[Thales]

I was actually vinegar dosing when the last NO3 test was taken last October for 4 or 5 months. Saw no difference in phosphate levels - I wonder if that was what was keeping the NO3 low. We'll see what happens.
I am also wondering if the NO3 reading is accurate...and if it is, maybe my RDSB needs a revamp or a removal. Interesting.
No idea what the target will be - if the NO3 is really that high, and the tank looks fine and the corals are growing....

 

[toothman]

Just thought I would throw my 2 cents in. Thales I saw you posted on my aefw thread, so you know how I feel about my tank. My nitrates are about 5 and my phosphate is .04. My lighting may be of interest it is 4 t5 actinic and three 250 watt halide unshielded 4" above the tank in both fixtures above tank. The halides run 7 hrs a day and t5 14 hrs a day. I think my coral colors is great. I also use hanna 736 ppb meter to check phosphate, I have found that the only way to have it read properly is to let the test vial sit for 2 plus hrs. it may seem crazy but doing the same method with faunna marin reference water yield almost exact results. Also think actinic lighting is the key to great colors.

My tank now, may not be around too much longer with aefws.<a href="http://s382.photobucket.com/user/eralff/media/photo18.jpg.html" target="_blank"><img src="http://i382.photobucket.com/albums/oo268/eralff/photo18.jpg" border="0" alt=" photo photo18.jpg"/></a>

 

[alexx2208]

Thales, how do you control your phosphates?

 

[dkeller_nc]

Even so, that NO3 number makes me at least superstitiously nervous and I have started adding vinegar to the top off. I'll try to put up the dosage I am using as well as a current pic of the tank later tonight.

Rich - just a comment based on my (and other's) experience. Adding vinegar to top-off water sometimes doesn't work out so well in that it seems to grow bacteria and/or mold. I tried to sterilize the ATO pump, tubing and 5 gallon bucket to prevent this, but the microorganisms simply returned after 3 or 4 days. That had the effect of consuming the vinegar that I wanted to get into my tank, as well as creating a bunch of bacterial slime in my ATO reservoir that tended to clog the pump.

It's for that reason that I went back to using a graduated eye dropper to simply add 4-5 mL of vinegar per night.

 

[Thales]

Rich - just a comment based on my (and other's) experience. Adding vinegar to top-off water sometimes doesn't work out so well in that it seems to grow bacteria and/or mold. I tried to sterilize the ATO pump, tubing and 5 gallon bucket to prevent this, but the microorganisms simply returned after 3 or 4 days. That had the effect of consuming the vinegar that I wanted to get into my tank, as well as creating a bunch of bacterial slime in my ATO reservoir that tended to clog the pump.

It's for that reason that I went back to using a graduated eye dropper to simply add 4-5 mL of vinegar per night.

Interesting. No way am I going to do that because I am lazy. Seriously, the system is set up so I can go on vacation or go to the field and all the tank sitter should need to do is feed.

I am also not dosing just vinegar in water. We do this at work, and I have done it at home - spike vinegar with Kalk and rinse the 40 gallon container from time to time. Never seen any bacterial slime over the years. I should also say that this is not my only top off. I also have set up a just water top off on a set of float switches. The vinegar/kalk is set up with a peri pump on a timer so the vinegar/kalk dose can be what it needs to be and isn't dependent on changing evaporation rates. Perhaps the addition of the Kalk is stoping bacterial growth.

A good heads up though. I would be interested to know why yours grew bacteria, and why others don't seem to. Any idea? That would make a cool side by side experiment.

 

[tmz]

The white vinegar is typically only 5% acetic acid and 95% water. At that strength the pH is low enough ( around 4.5,IIRC) to suppress the bacteria .When the acetic acid is diluted further, the pH rises and the bacteria consume the acetate .

The high pH of fully saturated limewater(12.4) also keeps the bacteria at bay .The acetic acid also ups the max saturation level for the calcium hydroxide. (48ml of plain white 5% vinegar per gallon raise the saturation level by 36% ,ie from 2tsps of calcium hydroxide per gallon to 2.72(per Bingman,who did the experiments as cited in Sprung an Delbeek's ,The Reef Aquarium vol 3.
Vinegar drops a lot H+ when it is added to the tank causing precipitous pH drops. It makes up for the pH initially lost later in the breakdown process to acetate , leaving only the much smaller pH loss from CO2 produced by bacteria a they consume the acetate to deal account for. . Significant quantities of acetic acid should be dosed slowly, preferably during periods of photosynthesis to minimize the initial effect it has on pH, allowing time for CO2 equilibration between the tank water and the air

 

[tmz]

Back to the orthophosphate (aka Pi/PO4 species) discussion.
Anecdotally, .02ppm to .04 ppm,per hanah colorimeter, provides adequate Pi for dense populations of richly colored non sps and lps while nuisance algae in my aquariums is limited.,fecundity is good in terms of sponges, fish breeding and coral growth. I feed a lot too. There have been no significant issues at these levels for over 5 years now. Hard to discuss PO4 without nitrogen(NO3 hovers between undetectable and 0.5ppm per Salifert test).
Earlier on ,I grew corals without paying much attention to PO4 and NO3. I had periods of a good year or two but something would happen and I'd loose specimens. I don't pretend to know exactly what caused the downturns or that the PO4 levels I manage for are the best for every tank or even the most optimal for mine but the results have been pleasing.

 

[Thales]

Here is a pic from tonight

Alk = 3.377
Ca = 452.4
Mg = 1337.5
NO3- = 100.7
PO43- = 1.392

The initial discussion of the numbers are here - http://www.reefcentral.com/forums/showpost.php?p=22356332&postcount=322

 

[Thales]

 

[tmz]

tested with the Hach ascorbic acid molybdate method.

So, orthophosphte only,ok. Wonder what a Hack PO-24 kit would show as it releases organically bound phosphate and brings it into the orthophosphate measure.

 

[AbrahamS]

Here is a pic from tonight

Alk = 3.377
Ca = 452.4
Mg = 1337.5
NO3- = 100.7
PO43- = 1.392

Really is that your levels? how its possible?

 

[Allmost]

we have not been able to come up with any rational explanation for this case.

it can not be that corals do not care for water quality. if that was the case, ppl would not loose corals and ppl would not have brown corals ... oceans would also not be effected by our pollution ... that is not the case in reality, so something is off ...

so either we have ALL been wrong ... and our values are NOT even close to what our test kits show. [which cant be , as many have been verified by labs ... ] or that something else is happening here.



we still have not seen any close up pictures of SPS corals ...

Thales, just like u started skeptical reef thing ... we have to be skeptical of your test results and observations as well.
at your work, do other scientists also believe that water quality doesnt matter? and if they do, why do they continue filtering their tanks ? why do ppl who research in this field control nutrients ?

 

[tmz]

It's obviously possible as it has been reported by reeefkeeper with significant credentials.Whether it's sustainable or has a general application value for other systems are still an open questions;I'm skeptical about that.
I think the discussion would benefit from more information about how corals and other organisms in the aquarium actually use phosphate. Perhaps Thales has some information on what happens to the Pi as organisms use it.
I have no reason to question his ability to test and the Hach tests are quality tests by most accounts.
It would have been nice to have a few data points on relative levels of Pi and organic phosphate as PO4 levels rose from .3 to 1.3 ppm to provide a clue as to what may actually be happening not only to the PO4 level but to the organics and bound elements including Pi in this particular puddle of eutrophic water.

 

[Thales]

we have not been able to come up with any rational explanation for this case.

Sure we have. We just don't know if any of them are true or not.

it can not be that corals do not care for water quality.

No one is arguing that. It could be a combination of water qualities impact corals differently, it could be that our standard levels were/are based on insufficient evidence (perhaps the standard levels reflect attempts to make things more like the ocean from a time when it was difficult to keep anything alive).

if that was the case, ppl would not loose corals and ppl would not have brown corals

That is a tough one. We don't really know why people are losing corals, especially in newer systems.

... oceans would also not be effected by our pollution "¦

Depends on what you mean by pollution.

that is not the case in reality, so something is off "¦

Again, maybe.

so either we have ALL been wrong "¦

That is too absolutist for me- we could be partially wrong, or stuck with 'this is what has been successful in the past'.

and our values are NOT even close to what our test kits show. [which cant be , as many have been verified by labs ... ] or that something else is happening here.

I am not a fan of any water test being relied on as accurate. They all worry me, and I much prefer to think of them as general trends rather that specific results. I look at all water test results with a squinty eye.

we still have not seen any close up pictures of SPS corals ...

I'll get some if I have time, though I am not sure what that would inform. Julian was pretty happy with the health and color of the corals if that is useful.

Thales, just like u started skeptical reef thing ... we have to be skeptical of your test results and observations as well.

Of course. I am skeptical of those test results too, as I have tried to be clear about. Please also realize that mostly I am just reporting, not trying to provide conclusions.

at your work, do other scientists also believe that water quality doesnt matter? and if they do, why do they continue filtering their tanks ? why do ppl who research in this field control nutrients ?

I am not sure where you are getting the idea that anyone thinks that water quality doesn't matter.

 

[Browncoat]

Pardon me if this has already been brought up I've read a good amount of the thread but not every page. Is it possible here that we have a case of "old tank syndrome"? The current animals in the tank (SPS) have adapted to the high Phosphate levels because they crept up very slowly over time?
I'd be interested to hear when the last time was that you introduced a completely new Acro to the tank and what was the effect on the coloration. Or what would happen to a known to be demanding Acro that was dropped in the tank today,

 

[dkeller_nc]

Perhaps the addition of the Kalk is stoping bacterial growth.

A good heads up though. I would be interested to know why yours grew bacteria, and why others don't seem to. Any idea? That would make a cool side by side experiment.

I imagine that the kalkwasser is doing the trick for keeping your system sterile. In my case, I run a kalk reactor, so the ATO water is plain ole RODI, and the amount of vinegar I was adding was insufficient to prevent acetobacter from growing.

However, your post has given me an idea - there's no particular reason I couldn't add a small amount of lime to the ATO reservoir and then run that through the kalk reactor.

But having said that, and given the very high sensitivity of a reef tank to small doses of vinegar/vodka/sugar, I will likely stick to adding a measured amount nightly, as the evaporation rate this time of year is just too unpredictable - hardly any at all one day, a couple of gallons the next.