Phosphate too low.....

Scubajoe1

New member
OK so I was running my GFO on my 180 and the water was just way too clean. This can be misleading at times with the Hanna checker because I found that if the vial is not cleaned inside and out prior to use you WILL get higher than actual readings. I gave measured and got 20 ppb (0.06 pppm) and then cleaned the entire vial inside and out then retested and got 0 ppb or 1 or 2 or some crazy low number. I realized something was up when it was reading 20 ppb but I was not seeing any blue tint to the water sample. Anyway, I was seeing some negative effects on my SPS and read that the water can be really devoid of phosphates too much so that it would cause this. I lessened the flow on my GFO reactor and took it off now 3 days ago. Still getting really low values like 3 ppb this morning. I have been feeding like nuts including oyster feast. How long before my phosphates increase?

Thanks

Joe
 
I'm sorry to hear about your testing problems with the Hanna unit. I'm not sure how long the phosphate level might take to increase, but 3 ppm, if we could assume that's accurate, would be fine. Unfortunately, our testing equipment isn't all that precise in that range. I'd keep up the same feeding rate for a while, and watch the corals. Have they been responding yet?
 
I'm sorry to hear about your testing problems with the Hanna unit. I'm not sure how long the phosphate level might take to increase, but 3 ppm, if we could assume that's accurate, would be fine. Unfortunately, our testing equipment isn't all that precise in that range. I'd keep up the same feeding rate for a while, and watch the corals. Have they been responding yet?

Jonathan. I am assuming you mean 3 ppb would be fine right? I have not noticed anything yet but it's only been a couple days since I removed the GFO reactor.
 
It should come up quickly with the feeding and no gfo. IMO /IME around 0.01 to 0.03 ppm is a good level for minimizing nuisance algae and keeping corals happy .
 
There are different types of bacteria at work. They all need some bound nitrogen( ammonia, nitrite and/or nitrate,etc. ) and phosphate( organic and/inorganic and some other elements like iron and potassium. The heterotrophic types need organic carbon too. The autotrophs not so much. They will be limited by the nutrient in short supply regardless of how high the others are. Extra food contains all of these nuteints .

GFO removes PO4 ,some inorganic phosaphte ,silicate and some metals.

Creating and sustaining balance between nutrient inputs ( feeding, respiration, waste, organics from living organisms, etc) and export via biofiltration and mechanical filtration can be done in different ways including:

removers like GFO, skimming, GAC;

dosing organic carbon , nitrate and /or phosphate in a search for and optimal proportions for a specific aquarium;

detritus removal methods(socks, siphoning et al.;

refugia with or without algae and with or without light;

extra surface areas particularly those including hypoxic zones ;

other methods.

In my system small frequent water changes (to replenish many major , minor and trace elements and draw the proportions into balance),dosing limewater for calcium and alkainity , heavy feeding, heavy skimming , extra live rock and sand in unlit refguia, organic carbon dosing ( vodka and vinegar) and a small amount of GAC provide an environment for variety of vibrant and long lived corals and other animals:PO4 0.02ppm to 0.04ppm per hanah 713; nitrate 0.02 to undetectable per salifert test . Once in a while I tweak nitrogen with tiny ( 1 tsp of sodium nitrate for 650 gallons) when I have undetectable readings I'm not sure it helps but seems to result in a small tweak dwon in PO4 afterwards. The problem is it may also create an uptick in nuisance algae.
 
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There are different types of bacteria at work. They all need some bound nitrogen( ammonia, nitrite and/or nitrate,etc. ) and phosphate( organic and/inorganic and some other elements like iron and potassium. The heterotrophic types need organic carbon too. The autotrophs not so much. They will be limited by the nutrient in short supply regardless of how high the others are. Extra food contains all of these nuteints .

GFO removes PO4 ,some inorganic phosaphte ,silicate and some metals.

Creating and sustaining balance between nutrient inputs ( feeding, respiration, waste, organics from living organisms, etc) and export via biofiltration and mechanical filtration can be done in different ways including:

removers like GFO, skimming, GAC;

dosing organic carbon , nitrate and /or phosphate in a search for and optimal proportions for a specific aquarium;

detritus removal methods(socks, siphoning et al.;

refugia with or without algae and with or without light;

extra surface areas particularly those including hypoxic zones ;

other methods.

In my system small frequent water changes (to replenish many major , minor and trace elements and draw the proportions into balance),dosing limewater for calcium and alkainity , heavy feeding, heavy skimming , extra live rock and sand in unlit refguia, organic carbon dosing ( vodka and vinegar) and a small amount of GAC provide an environment for variety of vibrant and long lived corals and other animals:PO4 0.02ppm to 0.04ppm per hanah 713; nitrate 0.02 to undetectable per salifert test . Once in a while I tweak nitrogen with tiny ( 1 tsp of sodium nitrate for 650 gallons) when I have undetectable readings I'm not sure it helps but seems to result in a small tweak dwon in PO4 afterwards. The problem is it may also create an uptick in nuisance algae.

Thanks Tom. I was wondering if phosphate was being removed quickly by GFO would the lack of phosphate prevent bacteria from removing the nitrate? Granted my nitrate level is only about 1 ppm right now and 0 ppb phosphorus (hanna).
 
Yes a phosphate deficiency is possible when using gfo ; the bacteria and other organisms can be limited by a lack of phosphate.0 ppb is low and could indicate a deficiency depending on the accuracy of the reading.

I'd keep feeding,stop the gfo .. and monitor PO4 levels and NO3 levels.

What's the NO3 level now?

If you want to raise only PO4 stopping the gfo should do it given the feeding routine.

Alternatively you can dose some phosphate but since you are feeding well I don't think that's necessary. Some folks have used Seachem flourish phosphorous
( an additive designed for fresh water panted tanks) with success. It will also add some potassium though which can build up if you use a lot of it over time.
 
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NO3 levels are less than 1 ppm. Probably about 0.75 ppm. I stopped the GFO 3 days ago now....feeding as usual and was at 1 ppb tonight. I have noticed with the hanna test that it is always going to give a higher reading than actual due to micro bubbles or fingerprints on the vial. so I am still basically at 0 or 0.003 ppm max. I think this is helping because I can swear the SPS look happier. I also have a green tree leather that has been closed up for over a week now and has started opening up tonight. I know the LPS like it a bit dirtier but it's a good indicator. Also I am sure the corals are probably sucking up the phosphate I am adding in terms of food. Just need to monitor closely and reach that balance now. SO CLOSE!!!
 
Sounds good. FWIW I haven't used gfo in over two years; just organic carbon dosing. Corals including sps seem to do better without it at the levels I noted in an earlier post.

FWIW I handle the vials with a paper towel and do my best to get a bubble free solution by filling the vial a syringe( a baby med feeder type)
 
Thanks Tom. Yeah that's what I do as well. Chemist here so I have all the needed supplies. I see vids online of people shaking it like mad but i just gently turn it for two minutes top to bottom about one second each. I also noticed that for whatever reason I can get a reading like 2o ppm and the solution is clear to my eye no blue tint, then I take dawn dishwashing liquid and a small paper towel with water and clean the inside, ride then after I get a more accurate reading closer to the colorless solution. With there was a small bottle brush to clean the inside but I have not found one yet.
 

That's one brand/source. Another one is Tunze's brush set - it contains a couple of extra-small, stiff brushes that will fit in the Hanna vials.

One comment I'd make is that 100 ppb phosphorus or lower, you're not going to be able to see the blue molybdenum-phosphate complex, which is one reason for the popularity of the the Hanna checkers.

Another thought about using the Hannas is to thoroughly clean the outside of the vial before filling it with tank water to establish the blank reading, then only handling the vial during addition of the reagents by the cap and perhaps the upper 1/4" of the vial. It's also helpful to the repeatability of the assay to orient the vial in the checker in the same position during the blanking and result reading. It's pretty easy to do by simply orienting the "10 mL" labeling towards the front of the checker.
 
I leave a drop or two of RO water in the vial( after rinsing it with tap water and then ro.di water) before storing it; seems to help keep it clear.

I do get false high readings from time to time when I stir too vigorously. Solution puddles up inside the cap and streams down the outside during the test. Even a little throws it off as much as 0.05/6ppm. Usually I remove the cap after two minutes of gentle swirling and wipe the inside of the cap dry and put it back on before starting the test.
 
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That's one brand/source. Another one is Tunze's brush set - it contains a couple of extra-small, stiff brushes that will fit in the Hanna vials.

One comment I'd make is that 100 ppb phosphorus or lower, you're not going to be able to see the blue molybdenum-phosphate complex, which is one reason for the popularity of the the Hanna checkers.

Another thought about using the Hannas is to thoroughly clean the outside of the vial before filling it with tank water to establish the blank reading, then only handling the vial during addition of the reagents by the cap and perhaps the upper 1/4" of the vial. It's also helpful to the repeatability of the assay to orient the vial in the checker in the same position during the blanking and result reading. It's pretty easy to do by simply orienting the "10 mL" labeling towards the front of the checker.

About the blue color....100 ppb is 0.31 ppm. I am pretty sure I have seen a blue tint when it was less than that but maybe not. I will have to post at what point I can see the blue tint visually if I ever get my phosphates to rise. Day 5 post removal of the GFO and still at 1 ppb so basically 0 ppm. I think the corals are sucking it up as I am seeing new white tips on a few corals. Fed some amino acids tonight along , oyster feast and the food for the fish and threw a couple cubes of frozen rotifers. Don't want to go overboard but dang I am not seeing any change yet.
 
I'm in the same boat scubajoe. I removed the GFO about 30 days ago and the Hanna gives me a 0.00 reading every week. I am anxiously awaiting it to rise. No3 is .25 via Red Sea pro test kit. I am considering dosing potassium nitrate but not excited to start down that path.

The bright side is I have increased mighty feedings with oyster feast, acro power and reef chili. One of each every three days. But more importantly I'm seeing growth and color improve with each passing week.

If it was easy everyone woukd do it, huh? :dance:
 
I don't see blue even at .02ppm but that's with my eyes and the 713.

Maybe the corals are getting more organic phosphate without the GFO helping the growth you noted.

Mine which were doing ok with moderate GFO use and heavy feeding have shown more growth and richer / less pastel color, since I stopped GFO over two years ago even though measured PO4 levels are about the same( 0.02ppm to 0.04ppm) as they were. The feeding ,which is relatively heavy, remained constant. The PO4 went up a few hundredths of ppm after a week or so without GFO ; a 10% increase in the vodka/vinegar dose brought it back down and has kept it. LPS like calulastrea, euphlylia, cahlice corals, fungia and a few others seem to do much better without the gfo in my case.

I'd skip the amino acids, personally; they don't add any phosphate. Phosphate aside, I've tried several types over the years without discernible benefits to corals. I think in a fed tank there are plenty available and corals synthesize most of what the y need in any case.
 
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I don't see blue even at .02ppm but that's with my eyes and the 713.

Maybe the corals are getting more organic phosphate without the GFO helping the growth you noted.

Mine which were doing ok with moderate GFO use and heavy feeding have shown more growth and richer / less pastel color, since I stopped GFO over two years ago even though measured PO4 levels are about the same( 0.02ppm to 0.04ppm) as they were. The feeding ,which is relatively heavy, remained constant. The PO4 went up a few hundredths of ppm after a week or so without GFO ; a 10% increase in the vodka/vinegar dose brought it back down and has kept it. LPS like calulastrea, euphlylia, cahlice corals, fungia and a few others seem to do much better without the gfo in my case.

I'd skip the amino acids, personally; they don't add any phosphate. Phosphate aside, I've tried several types over the years without discernible benefits to corals. I think in a fed tank there are plenty available and corals synthesize most of what the y need in any case.

Tom,
I tend to agree regarding the amino acids. They may help supplement corals that are starving but in a well fed tank I think they should get plenty. I don't believe still no phosphate. My skimmer does a great job though so maybe they are being pulled out with that and with corals consuming it. I was really giving it the double whammy with the GFO.

I checked tonight and it was 9 ppm but then I said let me clean the inside of the vial as well. I always wipe the outside with paper towels to remove all the fingerprints. After I cleaned the inside and tested again...0 ppb. Fish were happy because I fed three brine cubes and two frozen rotifer cubes. Will add sone oyster feast tonight. Feed me Seymour!!! That's what I imagine the corals saying now.
 
So I made up a solution of 100 ppm phosphorus and tested that both with the low range and ULR hanna checker. I added 10 uL of the 100 ppm to the 10 mL vial. My tank water is still reading 0 ppb. Anyway, when I did this I got 0.097 ppm.....expected value 0.1 ppm so pretty decent. I also tried the low range phosphate checker and got 0.24 ppm phosphate which is about 0.08ppm phosphorus so not as accurate. I could see a slight tint of blue at this level for both kits. Just an FYI for what it's worth.
 
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