Enormous unexplained PO4 swing

[blueoverbrown]

My tank normally runs with PO4 around 0.02 to 0.04. I lve been battling dinos and dosed a bit of neophos and left town for three days. I dosed 4ml two days apart. It really should have just added a touch of phosphate. Earlier today I measured 0.45 po4. I cranked up the refugium light and turned on the skimmer that is normally off, now it's climbed to 0.9 and probably higher, that's the Hanna checker's top limit. I'm currently mixing the water for a big water change, I'm afraid for my acros.

I don't see anything dead in the tank, all fish are accounted for. I'm so confused. Any insights?

 

[Reginald Reefer III]

NeoPhos Pro or just NeoPhos? Pro is 5x stronger.

What size of tank? 4ml of either won’t raise PO4 that much. Something else is going on.

 

[archipelago]

Hm interesting issue.

First thing- there isn't a whole lot of normal stuff that would cause an enormous spike like this. So, if your corals and fish look happy, don't freak out and don't do anything drastic!!

1. Unless corals are looking sick, hold off on the massive water change. If your tester is bad, you undoubtedly will make the Dino problem worse, and potentially cause other problems.
2. Phone a friend, stop by PetSmart, whatever but get a second, independent check on PO4.
3. What's your tank volume? 4 ml in 100 gal should increase PO4 ~ 0.05 ppm. 0.1 ppm increase for a 50 gal tank, and so on.
4. Are your PO4 checker reagents within expiration dates?
5. I use Hanna exclusively, and they are not without issue. Occasionally, I'll get a packet of ULR Chlorine reagent that has become clumpy, and causes the chlorine reading to be off the chart. Is the PO4 reagent in the packet, completely dry, and a fine dust? If it's clumpy (even slightly, it may be causing a false positive). I also purchase testing standards for all Hanna Checkers I use, to rule out a problem with the checker itself if I have an issue.
6. Less likely - restarting on offline piece of gear (skimmer) could potentially stir up detritus that might contribute to increasing phosphate.
7. Also less likely - Assuming no huge die-off of algae from the refugium?
8. Also less likely - any chance someone could have dumped a large dose of NeoPhos in the tank? Or, have you recently fed a large amount of ReefRoids? (I use RR to increase PO4 in my system. 1 teaspoon in my 150 gallon SPS system will increase PO4 by 0.10 ppm.
9. Last thing off the top of my head (and also less likely) - do you normally dose A4R, and have recently switched to a different dosing system? I use A4R and I observe a significant carbon dosing effect using it.

Will keep an eye on your thread.

 

[vetteguy53081]

Can be overfeeding, use of tap water, frozen foods, poor or no skimming and overstocking as examples
Assure youre not getting false readings

 

[Pod_01]

Just out of curiosity:

Last thing off the top of my head (and also less likely) - do you normally dose A4R, and have recently switched to a different dosing system? I use A4R and I observe a significant carbon dosing effect using it.

What do you mean by a significant carbon dosing effect?

Is it reduction in pH or NO3 reduction or something else?

 

[blueoverbrown]

Hm interesting issue.

First thing- there isn't a whole lot of normal stuff that would cause an enormous spike like this. So, if your corals and fish look happy, don't freak out and don't do anything drastic!!

1. Unless corals are looking sick, hold off on the massive water change. If your tester is bad, you undoubtedly will make the Dino problem worse, and potentially cause other problems.
2. Phone a friend, stop by PetSmart, whatever but get a second, independent check on PO4.
3. What's your tank volume? 4 ml in 100 gal should increase PO4 ~ 0.05 ppm. 0.1 ppm increase for a 50 gal tank, and so on.
4. Are your PO4 checker reagents within expiration dates?
5. I use Hanna exclusively, and they are not without issue. Occasionally, I'll get a packet of ULR Chlorine reagent that has become clumpy, and causes the chlorine reading to be off the chart. Is the PO4 reagent in the packet, completely dry, and a fine dust? If it's clumpy (even slightly, it may be causing a false positive). I also purchase testing standards for all Hanna Checkers I use, to rule out a problem with the checker itself if I have an issue.
6. Less likely - restarting on offline piece of gear (skimmer) could potentially stir up detritus that might contribute to increasing phosphate.
7. Also less likely - Assuming no huge die-off of algae from the refugium?
8. Also less likely - any chance someone could have dumped a large dose of NeoPhos in the tank? Or, have you recently fed a large amount of ReefRoids? (I use RR to increase PO4 in my system. 1 teaspoon in my 150 gallon SPS system will increase PO4 by 0.10 ppm.
9. Last thing off the top of my head (and also less likely) - do you normally dose A4R, and have recently switched to a different dosing system? I use A4R and I observe a significant carbon dosing effect using it.

Will keep an eye on your thread.

I think the tester is accurate. Normally after putting the powder into the sample it remains clear. This time it is turning very noticably blue.

Tank volume is 55 gallons with a 20 gallon sump. I have a ton of rocks so I'm estimating 55 gallons total system volume.

PO4 packets are brand new. No gear was restarted until after the spike.

Chaeto in the refugium is happy and healthy.

No one dumped anything in the tank. I did target feed a bit of reef roids last week. Maybe a 1/4 teaspoon tops.

I don't use A4R. I have alk, mag, calcium and neo nitro on a dosing pump. Usually nutrients run so low I dose 1 ml daily of neo nitro to keep no3 above zero.

The tank has been well established for 14 months now and I've never had a nutrient spike this. The only other thing I can think of is this... I recently busted up some Marco Rock from the tank and glued it onto the rockwork to accommodate some acro frags. I guess because I have fresh rock surfaces it could be leeching po4?

Also, I did have a bit of an overfeeding incident last night but it wasn't drastic. I added some frozen food at night that wasn't not eaten. It wasn't any larger than say 2 m&M's. Doesn't seem like that would cause a spike this

 

[archipelago]

Just out of curiosity:

What do you mean by a significant carbon dosing effect?

Is it reduction in pH or NO3 reduction or something else?

NO3 and PO4 reduction.

I dose the equivalent of 0.10 ppm PO4 and 1 ppm NO3 daily to maintain detectable levels. Tunze 9430 skimmer set to lowest setting (no skimmate). 8 x Anthias, 2 x Regal Angels, 4 x cubes of Ocean Nutrition, 1 x tsp NLS, ~ .75 tsp ReefRoids daily.

If I go 2 days without dosing PO4 and NO3, my PO4 bottoms out so hard, some of my corals immediately begin to STN, followed by major Dino outbreak. This happens like clockwork.

I've got two more Anthias and 10 Chromis coming tomorrow to help with nutrients!

 

[Pod_01]

I recently busted up some Marco Rock from the tank and glued it onto the rockwork to accommodate some acro frags. I guess because I have fresh rock surfaces it could be leeching po4?

That can be possible source of PO4, but one minor correction.
Rocks desorb PO4 to reach new equilibrium with water column, rocks do not leech PO4.

Also, I did have a bit of an overfeeding incident last night but it wasn't drastic. I added some frozen food at night that wasn't not eaten. It wasn't any larger than say 2 m&M's. Doesn't seem like that would cause a spike this

I tend to test PO4 long before anything gets into water or long after anything got into water.
From my experience feeding can substantially impact PO4 test results.
I tend to test late at night for consistency.

 

[Pod_01]

NO3 and PO4 reduction.

I dose the equivalent of 0.10 ppm PO4 and 1 ppm NO3 daily to maintain detectable levels. Tunze 9430 skimmer set to lowest setting (no skimmate). 8 x Anthias, 2 x Regal Angels, 4 x cubes of Ocean Nutrition, 1 x tsp NLS, ~ .75 tsp ReefRoids daily.

If I go 2 days without dosing PO4 and NO3, my PO4 bottoms out so hard, some of my corals immediately begin to STN, followed by major Dino outbreak. This happens like clockwork.

I've got two more Anthias and 10 Chromis coming tomorrow to help with nutrients!

Interesting, I wonder if it is due to the trace elements in A4R vs. carbon dosing effect. The added trace element may reduce some limitation and happy corals consume all the available PO4. Sounds like you have nice system… With the fish load you may have sufficient N source…

I observed STN from the base of my coral from dropping or low PO4, my system usually runs NO3 at 1ppm or less but I try to keep PO4 between 0.1-0.4ppm. Anytime my PO4 gets below 0.05ppm my corals are not happy.

 

[Tangdora]

How bad is your Dino issue. If it’s sever a rapid dy off can raise your levels. Did you notice any big reduction prior to spike.

 

[archipelago]

I think the tester is accurate. Normally after putting the powder into the sample it remains clear. This time it is turning very noticably blue.

Yep, makes sense - with levels ~ .02-.04 the color change with reagent is barely noticeable.

Tank volume is 55 gallons with a 20 gallon sump. I have a ton of rocks so I'm estimating 55 gallons total system volume.

I did target feed a bit of reef roids last week. Maybe a 1/4 teaspoon tops.

This could be a contributing factor. While there is probably some variability in resulting PO4 levels when feeding in different systems - using my tank as an estimate; your 55 g system would show ~ 0.08 ppm increase with ~ 1/4 tsp of RR...

PO4 packets are brand new.

Would still not rule out the reagent as a concern, would grab a second test kit to verify levels.

No gear was restarted until after the spike.

You mentioned turning skimmer on somewhere between 0.4 and 0.9 ppm PO4 readings. Probably unlikely, but that's what stuck in my head.

Chaeto in the refugium is happy and healthy.

Figured, and ruled out.

No one dumped anything in the tank.

OK. Per @Reginald Reefer III 's question above - did you confirm you are using the non-pro version of Neophos? At 5x the strength, a 4 ml dose would have increased PO4 by ~ 0.50 ppm.

I don't use A4R. I have alk, mag, calcium and neo nitro on a dosing pump. Usually nutrients run so low I dose 1 ml daily of neo nitro to keep no3 above zero.

Makes sense.

The tank has been well established for 14 months now and I've never had a nutrient spike this. The only other thing I can think of is this...

I recently busted up some Marco Rock from the tank and glued it onto the rockwork to accommodate some acro frags. I guess because I have fresh rock surfaces it could be leeching po4?

Yes; uncured, mined rock is most certainly a significant PO4 source in an aquarium.

Also, I did have a bit of an overfeeding incident last night but it wasn't drastic. I added some frozen food at night that wasn't not eaten. It wasn't any larger than say 2 m&M's. Doesn't seem like that would cause a spike this

Agreed - minimal impact.

 

[archipelago]

Rocks desorb PO4 to reach new equilibrium with water column, rocks do not leech PO4.

LOL what's the difference?
Desorb = Rock PO4 -> Water PO4
Leech = Rock PO4 -> Water PO4

I wonder if it is due to the trace elements in A4R vs. carbon dosing effect. The added trace element may reduce some limitation and happy corals consume all the available PO4.

I've read this very thing in at least one post where Tropic Marin commented on similar 'complaints' (low PO4 + NO3). While this could be the overarching mechanism, it would stand to reason that coral growth might (would likely?) be commensurate with trace element uptake, and (I think it would be fair to assume) would result in a (somewhat) proportional Alkalinity uptake. In my system, I do not see steady, increasing uptake in Alkalinity proportional to the ongoing, steadily increasing demand for PO4 and NO3.

Sounds like you have nice system…

I'd like to think so!

With the fish load you may have sufficient N source…

Fingers crossed to this. I'd like to stop being dependent on NO3 dosing. Although conversely it is generally cheaper to dose nitrate than it is purchase the required equipment to reduce it.... The grass is always greener... LOL

I observed STN from the base of my coral from dropping or low PO4

Same

my system usually runs NO3 at 1ppm or less

Same, and I'm least concerned w/ NO3 levels. I'm dosing to maintain ~ 10ppm.

I try to keep PO4 between 0.1-0.4ppm

I'm maintaining between 0.20 - 0.30 (not 0.02 - 0.03) ppm, otherwise daily fluctuations can get me too close to Dino town.

Anytime my PO4 gets below 0.05ppm my corals are not happy.

Same

 

[Randy Holmes-Farley Verified Community Expert]

I would at least double check the Hanna on some new salt water.

The phosphate rise, if real, is not a panic, but I’d try to figure out what is adding it. I do not think any purely in tank processes will cause it.

 

[Pod_01]

LOL what's the difference?
Desorb = Rock PO4 -> Water PO4
Leech = Rock PO4 -> Water PO4

PO4 in the water column is always in equilibrium with bound PO4 in the rock structure. When the water column has elevated PO4 level compared to rock the rock will bind/bound PO4 until new equilibrium is reached. If PO4 drops the rock structure will desorb (use desorption mechanism) to release PO4 until new equilibrium with water column is reached.
GFO and all other PO4 removal media use the same mechanism.

The rock is not capable of storing PO4 over time and later to leach PO4 to a new higher level.

Just for reference these are my latest NO3 / PO4 values:

Some corals:

I believe N source like ammonia is preferred by corals, I use NO3 as an indicator to determine if enough N is in the system (for example ammonia from fish waste etc..).

As Randy mentioned I suspect the OP phosphate increase is from external source.

 

[blueoverbrown]

And today, as I tested again and got a reading of zero, I realized that yesterday the syringe i used to collect the water has been previously used to feed reef roids. I'm gonna leave this post up as a monument to my stupidity.

 

[Reginald Reefer III]

And today, as I tested again and got a reading of zero, I realized that yesterday the syringe i used to collect the water has been previously used to feed reef roids. I'm gonna leave this post up as a monument to my stupidity.

We all go through that! Good catch on the reef roids syringe. That will definitely do it!

 

[BryanM]

And today, as I tested again and got a reading of zero, I realized that yesterday the syringe i used to collect the water has been previously used to feed reef roids. I'm gonna leave this post up as a monument to my stupidity.

And this is why I won't ever use reef roids.

But congrats on figuring out the issue!

 

[KrisReef]

And today, as I tested again and got a reading of zero, I realized that yesterday the syringe i used to collect the water has been previously used to feed reef roids. I'm gonna leave this post up as a monument to my stupidity.

Amazing post, thanks for figuring out the source of error.

I was thinking the PO4 additive must be pure TSP or something. Fish food contamination for the knowledge win!

 

[archipelago]

And today, as I tested again and got a reading of zero, I realized that yesterday the syringe i used to collect the water has been previously used to feed reef roids. I'm gonna leave this post up as a monument to my stupidity.

Maybe funny, but one of the best outcomes, which is; nothing is wrong! Thanks for letting us know. One more thing for me to add to my list of 'silly' things to check when I can find an obvious answer.

Cheers!