Phosphate starvation

beanoil · 05/02/2008, 09:56 PM

Is there such a thing as phosphate starvation? Someone posted this in another thread:

Quote:

Yes, the zooxanthellae in coral needs some phosphate to grow, it IS an algae after all. Get a phosphate test kit and post your results. Sure high phosphate levels can do some harm to your SPS corals, however, a lack of phosphates will starve them and cause them to bleach. You may be running your water through your phosphate reactor too slowly thereby removing too much thereby causing your corals to starve.

I've never heard/read of this happening, but my softies and LPS don't seem to be doing as well in the four months since I put in a reactor. I've never used more than half the recommended dosage of Phosban and all GHA melted away. My corals aren't dieing, but don't look great either. So is this a possible issue?

Thanks,
Grant

littleoldme · 05/02/2008, 10:08 PM

Where are your nitrates and other levels at. Everytime you feed you add phosphate to your tank I doubt that is your problem. I think something else is not in line on where it should be. High nitrates being tops on the list.

bertoni · 05/02/2008, 11:21 PM

Phosphate is a macronutrient, and all organisms need it to grow. Some people have reported negative reactions to phosphate media if introduced in large quantities, but there are a lot of issues. You could experiment with lower doses of the PhosBan. Are there any Acropora or similar corals in the system?

beanoil · 05/03/2008, 07:58 AM

Littleoldme: Nitrates are undetectable, sg is 1.026, temp is 78.5-79.5, pH is low at 7.89-8.06, alk is low at 7 dKh, calcium is around 400.

Bertoni: No acros or SPS at all, just softies and LPS. I can't really experiment w/ less Phosban. I'm only using half the recommenced dosage for 70 gallon total volume--it's only about a half inch in the bottom of the reactor.

Thanks,
Grant

Billybeau1 · 05/03/2008, 09:09 AM

Well, I do not know whether the quote has any merit or not.

But, If your corals looked good before starting the reactor, I would shut it off for a month and see if you see a positive reaction.

If not PO₄, their are many other reasons for corals doing poorly.

Lighting, water flow, etc.

I would start with the basics like water chemistry and go from there.

Make sure your s.g. is between 1.025 and 1.027

Try and keep your calcium level above 400 ppm. 420 - 450 better.

Maybe bump your alk up a tad to allow for test kit noise. Maybe 9 dkh.

Just take your time and go slow. You'll figure it out.

Aquarist007 · 05/03/2008, 11:53 AM

are you running a refugium --IMO this is one area where there might be competition for available phosphates.
When I added my second refugium I had to stop the phospban reactor as suggested above

if you don't have a refugium then I would say that regular feedings of your corals---cycloopeeze and other zooplankton mixes would supply enough nutrients for the corals to flourish quite nicely

phosphates have two sides to them--increase them and they can brown corals so they really need to be measured and maintained a very low levels

Boomer · 05/03/2008, 12:09 PM

Grant, everything that has been stated, to include your quote, is correct or a possibility. ALL plants and animals have what is called PO4 Limiting and Nitrate Limiting factors. These are values that if not met will limit the animal/plant from growing and we do not know what these limits are for all of them. Even if the PO4 is within its Limit value water current alone can change that making it limiting.

Allot of this revolves around what we called Liebig's Rule.

" "Yield of any organism will be determined by the abundance of the substance that in relation to the needs of the organism is least abundant in the environment." So when nutrients become higher or above that limit, they are no longer a limiting factor.

Then there is what is called the Red Field Ratio, which also plays a roll. This is the ratio of carbon, nitrogen and phosphorus, often given as C-N-P, which usually is also their order of limiting, form the least to the most. In seawater it is usually 106-16-1, so P is the most limiting usually but at times, under the right conditions it may be N but it is never C. For example, Cyanobacteria are often more limited by N than P.

beanoil · 05/04/2008, 08:13 AM

OK everybody, thanks for the help. I think I'll take the reactor offline for a while and take a closer look at the other potential issues. Thanks again, the responses are much appreciated.

Grant

Aquarist007 · 05/04/2008, 10:08 AM

Quote:

Originally posted by Boomer
Grant, everything that has been stated, to include your quote, is correct or a possibility. ALL plants and animals have what is called PO4 Limiting and Nitrate Limiting factors. These are values that if not met will limit the animal/plant from growing and we do not know what these limits are for all of them. Even if the PO4 is within its Limit value water current alone can change that making it limiting.

Allot of this revolves around what we called Liebig's Rule.

" "Yield of any organism will be determined by the abundance of the substance that in relation to the needs of the organism is least abundant in the environment." So when nutrients become higher or above that limit, they are no longer a limiting factor.

Then there is what is called the Red Field Ratio, which also plays a roll. This is the ratio of carbon, nitrogen and phosphorus, often given as C-N-P, which usually is also their order of limiting, form the least to the most. In seawater it is usually 106-16-1, so P is the most limiting usually but at times, under the right conditions it may be N but it is never C. For example, Cyanobacteria are often more limited by N than P.

excellent post boomer--please join us on this thread:

http://www.reefcentral.com/forums/sh...8#post12467848

m2434 · 05/04/2008, 11:13 AM

BTW, how long has the reactor been going? Sometimes the initial drop can cause "shock", IME this is esspecially true for LPS corals and it can take time to recover. This can be avoided by adding reactor media slowly; just add a little more every day until the reactor contains the desired amount.

stony_corals · 05/04/2008, 06:51 PM

Just to tighten that definition of the Redfield ratio, the 106:16:1 (C:N:P) is specifically for phytoplankton, other organisms have their own Redfield ratios , i.e. macroalgae 550:30:1. I haven't found anything for corals... It seems to me that most often N will be limited, though this may not be the case with you are running GFO aggressively.

Boomer · 05/04/2008, 09:28 PM

Yes stony that is true, glad you tightened that up

05/02/2008, 11:21 PM	#3
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	Phosphate is a macronutrient, and all organisms need it to grow. Some people have reported negative reactions to phosphate media if introduced in large quantities, but there are a lot of issues. You could experiment with lower doses of the PhosBan. Are there any Acropora or similar corals in the system? __________________ Jonathan Bertoni

05/03/2008, 11:53 AM	#6
Aquarist007 Registered Member Join Date: Apr 2007 Location: Hamilton, Canada Posts: 28,240 Blog Entries: 1	are you running a refugium --IMO this is one area where there might be competition for available phosphates. When I added my second refugium I had to stop the phospban reactor as suggested above if you don't have a refugium then I would say that regular feedings of your corals---cycloopeeze and other zooplankton mixes would supply enough nutrients for the corals to flourish quite nicely phosphates have two sides to them--increase them and they can brown corals so they really need to be measured and maintained a very low levels __________________ I prefer my substrates stirred but not shaken Current Tank Info: 150gal long mixed reef, 90gal sump, 60 gal refugium with 200 lbs live rock

05/03/2008, 12:09 PM	#7
Boomer Bomb Technician (EOD) Join Date: Aug 2002 Location: Duluth, Minnesota Posts: 11,842	Grant, everything that has been stated, to include your quote, is correct or a possibility. ALL plants and animals have what is called PO4 Limiting and Nitrate Limiting factors. These are values that if not met will limit the animal/plant from growing and we do not know what these limits are for all of them. Even if the PO4 is within its Limit value water current alone can change that making it limiting. Allot of this revolves around what we called Liebig's Rule. " "Yield of any organism will be determined by the abundance of the substance that in relation to the needs of the organism is least abundant in the environment." So when nutrients become higher or above that limit, they are no longer a limiting factor. Then there is what is called the Red Field Ratio, which also plays a roll. This is the ratio of carbon, nitrogen and phosphorus, often given as C-N-P, which usually is also their order of limiting, form the least to the most. In seawater it is usually 106-16-1, so P is the most limiting usually but at times, under the right conditions it may be N but it is never C. For example, Cyanobacteria are often more limited by N than P. __________________ If you See Me Running You Better Catch-Up Seawater Chemistry, Geology, ID Marine Life, Collecting Science Books, Explosives Technology, Audiophile An explosion can be defined as a loud noise, accompanied by the sudden going away of things, from a place where they use to be.

05/04/2008, 11:13 AM	#10
m2434 Registered Member Join Date: Jan 2004 Posts: 2,171	BTW, how long has the reactor been going? Sometimes the initial drop can cause "shock", IME this is esspecially true for LPS corals and it can take time to recover. This can be avoided by adding reactor media slowly; just add a little more every day until the reactor contains the desired amount. __________________ Our imagination is stretched to the utmost, not, as in fiction, to imagine things which are not really there, but just to comprehend those things which are there. ~Richard Feynman

05/04/2008, 09:28 PM	#12
Boomer Bomb Technician (EOD) Join Date: Aug 2002 Location: Duluth, Minnesota Posts: 11,842	Yes stony that is true, glad you tightened that up __________________ If you See Me Running You Better Catch-Up Seawater Chemistry, Geology, ID Marine Life, Collecting Science Books, Explosives Technology, Audiophile An explosion can be defined as a loud noise, accompanied by the sudden going away of things, from a place where they use to be.

05/02/2008, 10:08 PM	#2
littleoldme Registered Member Join Date: Jul 2007 Posts: 32	Where are your nitrates and other levels at. Everytime you feed you add phosphate to your tank I doubt that is your problem. I think something else is not in line on where it should be. High nitrates being tops on the list.

05/03/2008, 07:58 AM	#4
beanoil Registered Member Join Date: Sep 2005 Location: PA Posts: 336	Littleoldme: Nitrates are undetectable, sg is 1.026, temp is 78.5-79.5, pH is low at 7.89-8.06, alk is low at 7 dKh, calcium is around 400. Bertoni: No acros or SPS at all, just softies and LPS. I can't really experiment w/ less Phosban. I'm only using half the recommenced dosage for 70 gallon total volume--it's only about a half inch in the bottom of the reactor. Thanks, Grant

05/03/2008, 09:09 AM	#5
Billybeau1 Registered Member Join Date: Jul 2005 Location: Dyer, Indiana Posts: 12,010	Well, I do not know whether the quote has any merit or not. But, If your corals looked good before starting the reactor, I would shut it off for a month and see if you see a positive reaction. If not PO₄, their are many other reasons for corals doing poorly. Lighting, water flow, etc. I would start with the basics like water chemistry and go from there. Make sure your s.g. is between 1.025 and 1.027 Try and keep your calcium level above 400 ppm. 420 - 450 better. Maybe bump your alk up a tad to allow for test kit noise. Maybe 9 dkh. Just take your time and go slow. You'll figure it out.

05/04/2008, 08:13 AM	#8
beanoil Registered Member Join Date: Sep 2005 Location: PA Posts: 336	OK everybody, thanks for the help. I think I'll take the reactor offline for a while and take a closer look at the other potential issues. Thanks again, the responses are much appreciated. Grant

05/04/2008, 06:51 PM	#11
stony_corals Registered Member Join Date: Apr 2006 Posts: 1,323	Just to tighten that definition of the Redfield ratio, the 106:16:1 (C:N:P) is specifically for phytoplankton, other organisms have their own Redfield ratios , i.e. macroalgae 550:30:1. I haven't found anything for corals... It seems to me that most often N will be limited, though this may not be the case with you are running GFO aggressively.