PO4 deficit

[kutcha]

So my tank for some reason will not register PO4 my Hannah checker always read 0.00 but my nitrates are 5 i am wondering how much of a negative effect will a sustained time of zero PO4 reading have no my tank/corals? A bit of information on the tank, i am running a Algae Turf Scrubber, skimmer, fuge and carbon reactor. I am debating on taking my skimmer offline but i worry about my Nitrates increasing.

 

[living_tribunal]

So my tank for some reason will not register PO4 my Hannah checker always read 0.00 but my nitrates are 5 i am wondering how much of a negative effect will a sustained time of zero PO4 reading have no my tank/corals? A bit of information on the tank, i am running a Algae Turf Scrubber, skimmer, fuge and carbon reactor. I am debating on taking my skimmer offline but i worry about my Nitrates increasing.

I would focus on the carbon reactor first as that would most likely export a disproportionate amount of phosphate to nitrate.

 

[Albertan22]

Reduce the amount of time your fuge light is on. The fuge and algae reactor won’t function without PO4 so they’re likely eating all of it. They process PO4 and nitrate in a ratio, with more nitrate being exported than phosphate. Once phosphate is depleted they can’t process any more nitrate. Running 0 phosphate will be bad for your coral in the long run, and could result in a Dino outbreak eventually.

 

[jda]

Are you actually having any problems with growth or color? Residual levels on a test kit are fools gold and availability is what drives the bus forward. Some of the best tanks can barely detect neither N or P.'

I would not use organic carbon, but other than this, I would not worry about now P levels.

 

[Albertan22]

I would focus on the carbon reactor first as that would most likely export a disproportionate amount of phosphate to nitrate.

I haven’t ever heard of carbon (GAC like you’d run in a reactor, not carbon dosing like vodka) removing phosphate or nutrients at all. Typically it’s just used for polishing the water and removing toxins isn’t it?

 

[living_tribunal]

Are you actually having any problems with growth or color? Residual levels on a test kit are fools gold and availability is what drives the bus forward. Some of the best tanks can barely detect neither N or P.'

I would not use organic carbon, but other than this, I would not worry about now P levels.

Running undetectable po4 is a fools game. Sure, there is most likely phosphate in the column that’s quickly absorbed by other members, but not smart to risk it.

 

[shred5]

So my tank for some reason will not register PO4 my Hannah checker always read 0.00 but my nitrates are 5 i am wondering how much of a negative effect will a sustained time of zero PO4 reading have no my tank/corals? A bit of information on the tank, i am running a Algae Turf Scrubber, skimmer, fuge and carbon reactor. I am debating on taking my skimmer offline but i worry about my Nitrates increasing.

It may have no affect. Lots of people run undetectable phosphate with no issues and have forever. Zeovite is one type of system.

Corals can get lots of their requirements from food, bacteria and supplements. It all depends how you treat your tank.. This only became a issue because so many are afraid of a little algae their tanks have become sterile and they feed the system little food.

 

[jda]

GAC removes and binds organics before they break down into n and p, so it does lower them in a from-the-front--end sort of way.

 

[kutcha]

Are you actually having any problems with growth or color? Residual levels on a test kit are fools gold and availability is what drives the bus forward. Some of the best tanks can barely detect neither N or P.'

I would not use organic carbon, but other than this, I would not worry about now P levels.

so i would say yes i am having some of my zoas starting to close and stay close and i had a dino outbreak about 5 months ago and i am at the tail end of that but i worry if the PO4 stays at zero it will encourage the dinos to bloom again.

 

[Albertan22]

@jda raises a good point. What are you measuring your phosphate with? I wouldn’t trust anything but a Hanna ULR for near zero levels. You may be just fine if you are using any test kit as it’s probably realistically somewhere below 0.05ppm. Zero on Hanna and I’d try to bump up a little, either by adjusting filtration or starting reef roids or something.

 

[kutcha]

@jda raises a good point. What are you measuring your phosphate with? I wouldn’t trust anything but a Hanna ULR for near zero levels. You may be just fine if you are using any test kit as it’s probably realistically somewhere below 0.05ppm. Zero on Hanna and I’d try to bump up a little, either by adjusting filtration or starting reef roids or something.

I am using a Hannah Checker and i use reef chili a few time a week

 

[living_tribunal]

I haven’t ever heard of carbon (GAC like you’d run in a reactor, not carbon dosing like vodka) removing phosphate or nutrients at all. Typically it’s just used for polishing the water and removing toxins isn’t it?

I haven’t ever heard of carbon (GAC like you’d run in a reactor, not carbon dosing like vodka) removing phosphate or nutrients at all. Typically it’s just used for polishing the water and removing toxins isn’t it?

That’s correct, read through a little fast. While carbon won’t directly bind to po4 like GFO, it will absorb some of it and definitely the inorganic gunk that will eventually convert to it.

 

[jda]

Do you change water? I have had Z&P unhappy over time when I did not change water - some of them super happy still while some got mad and colonies shrunk. With routine water changes, they thrived - probably a trace element thing.

Dinos is a problem with lack of diversity and sterile conditions. Usually, once you are past them, then you are past them. This is not always true in a tank start with dry/dead rock which can take years to fully get diverse, if ever. Raising P poisons/growth limits them, which is an OK stopgap for a while.

My tank is constantly 1 or 2 (sometimes 3) PPB on a hannah ultra low checker. This is more than enough, is near ocean level and nothing suffers. Growth is outstanding and so in the color.

You have to understand the relationship between aragonite and phosphate to understand that this is not likely any issue. The aragonite will bind P in relationship to the amount in the water column. The aragonite acts like a buffer in both good and bad ways - good when low since if the water gets too low, then the rock will release some... and bad if you have a high water concentration, then there is a MASSIVE reservoir bound in the rocks and sand. Only using chemicals or media (like organic carbon) will drive both the water level and aragonite level too low, which is why I do not suggest using it. In natural cases with fuges, scrubbers, skimmers, etc. there is no ability for the level to get too low.

When you add P to a tank, most of it just get bound to the rocks and sand.

You are getting 0 PPB on a Hannah Ultra Low Phosphorous Checker, not the normal Hannah Phosphate Checker? If so, then quit the organic carbon reactor for sure. This is generally a bad idea in a reef, but especially a bad idea in a low P (or low N) since it really is about the only way to growth limit corals with too low of levels (GFO and LC can do this too). Natural levels never seem to get them too low and always leave some to drive the equilibrium forward.

 

[kutcha]

Do you change water? I have had Z&P unhappy over time when I did not change water - some of them super happy still while some got mad and colonies shrunk. With routine water changes, they thrived - probably a trace element thing.

Dinos is a problem with lack of diversity and sterile conditions. Usually, once you are past them, then you are past them. This is not always true in a tank start with dry/dead rock which can take years to fully get diverse, if ever. Raising P poisons/growth limits them, which is an OK stopgap for a while.

My tank is constantly 1 or 2 (sometimes 3) PPB on a hannah ultra low checker. This is more than enough, is near ocean level and nothing suffers. Growth is outstanding and so in the color.

You have to understand the relationship between aragonite and phosphate to understand that this is not likely any issue. The aragonite will bind P in relationship to the amount in the water column. The aragonite acts like a buffer in both good and bad ways - good when low since if the water gets too low, then the rock will release some... and bad if you have a high water concentration, then there is a MASSIVE reservoir bound in the rocks and sand. Only using chemicals or media (like organic carbon) will drive both the water level and aragonite level too low, which is why I do not suggest using it. In natural cases with fuges, scrubbers, skimmers, etc. there is no ability for the level to get too low.

When you add P to a tank, most of it just get bound to the rocks and sand.

You are getting 0 PPB on a Hannah Ultra Low Phosphorous Checker, not the normal Hannah Phosphate Checker? If so, then quit the organic carbon reactor for sure. This is generally a bad idea in a reef, but especially a bad idea in a low P (or low N) since it really is about the only way to growth limit corals with too low of levels (GFO and LC can do this too).

I do a 20% WC every two weeks, and yes i started the tank off with dry/dead rock roughly a year ago and i added some new rock roughly 20 lbs about 3 months ago. the tank is a 75 gallon i had about 50 pounds when i started the initial cycle a year ago (with a bio brick in the fuge area)

 

[SPR1968]

If my Hanna reads zero I’m delighted because it has a margin of error of +/- 0.04 I think, the one I use anyway, and you really need to keep phosphate below 0.03 to avoid many of the issues you read about.

I use rowaphos and ‘heavy’ to keep it locked down.

If your feeding etc., the reading is unlikely to be absolute zero and you only need a tiny amount for cell formation etc.

So if everything is ok, I would leave well alone and certainly don’t actively try and increase it.

 

[Randy Holmes-Farley Verified Community Expert]

That’s correct, read through a little fast. While carbon won’t directly bind to po4 like GFO, it will absorb some of it and definitely the inorganic gunk that will eventually convert to it.

I do not believe that granular activated carbon can bind appreciable phosphate from seawater.

Presumably you mean organic gunk, not inorganic gunk. That part is certainly true, though I expect it is a very minor part of the phosphorus cycle in a reef aquarium.

 

[CindyKz]

You are getting 0 PPB on a Hannah Ultra Low Phosphorous Checker, not the normal Hannah Phosphate Checker?

This is an important distinction, so take a look at your test kit and see which one you have.

The regular Hanna Phosphate checker will read zero even with a fair amount of PO4 in the tank (at least mine did). If your PO4 is reading "0" on this test kit and you're concerned I would consider buying the Hanna Ultra Low test.

 

[nereefpat]

I am using a Hannah Checker

Which one? What number (HI736?)?

 

[jda]

A really smart guy who runs a chemistry forum on a reef board posted this once about phosphate... for fish, think gills and urine, not just urine like in people. Although this is too simple, I just figure that I am not going to be able to filter much phosphate on the front end since it is either inorganic from urine/gills or if it is solid/gunk, then it will get nearly all used up before my filters get it. If somebody wanted to argue that even a tiny percentage of organic gunk caught in GAC over the years with compound interest can still add up and make a dent, then I will not wast any words to the contrary.

I am, as it happens, an expert on phosphate metabolism. I've studied it for more than 20 years, and have invented products that sell more than a billion dollars worth each year correcting hyperphosphatemia in people.

There is a flow chart in this link which shows the relative excretion of phosphate in urine (which is almost totally inorganic phosphate) and in feces (which is a combination of organic and inorganic phosphate).

https://www.inkling.com/read/medica...-2nd/chapter-52/calcium-and-phosphate-balance

The inorganic phosphate in urine excretion dominates, even if you ignore all of the inorganic phosphate in the feces. Then you seem to assume that all of that feces ends up in the substrate, which is utterly untrue. Other macroscopic creatures eat it, sometimes over and over. I had a kole tang that loved to eat my yellow tangs feces as fast is it came out. That drops the original phosphate ending up in feces by another factor of three. Each cycle drops it significantly.

 

[kutcha]

Which one? What number (HI736?)?

i will have to check when i get home but i know it doesnt give me whole numbers it would give me like a .26 or a .05 for phos readings