YoYo Nitrate Level

[Dan_P]

A recent post asked how long before a change in PO4 and NO3 levels are detected after increasing the amount of daily fish food (http://www.reefcentral.com/forums/showthread.php?t=2673631).

Here is an example from a fish only system with a large amount of macro algae. Notice how the nitrate level increases after feeding and drops during the subsequent photo period.

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[bertoni]

That's interesting. It take a bit longer than I thought for the algae to consume the nitrate. You wouldn't happen to have the phosphate levels?

 

[taricha]

That's very cool. How are you measuring tenths of a ppm no3?
Looks like if you skipped a day feeding, the algae would have the nitrate zeroed completely.

 

[timnem70]

Mine is doing the same. Just 3 fish, large cleanup crew and assorted soft corals. I took my skimmer offline due to Macro being so efficient. Zoas wouldn't open. So now just a filter sock, small amount of filter floss and at least 3 species of Macroalge keep my Po4 and Po3 in check but allows for some trace. Its a 25 cube and I feed 2xdaily.

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[timnem70]

Sorry. No3

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[Dan_P]

That's interesting. It take a bit longer than I thought for the algae to consume the nitrate. You wouldn't happen to have the phosphate levels?

Unfortunately, the Hanna ULR P Checker is not detecting phosphate at this time.

The accumulation of nitrate was pretty quick. The implication is that ammonia production and subsequent ammonia oxidation can be quick. I thought things progressed somewhat more slowly after feeding. I need to ponder this observation a little longer.

 

[Dan_P]

That's very cool. How are you measuring tenths of a ppm no3?
Looks like if you skipped a day feeding, the algae would have the nitrate zeroed completely.

I use the Hanna ULR P Checker to measure the color intensity of the Red Sea nitrate test.

Tonight I started feeding half the number of mussels to see if the NO3 level zeros out.

 

[Dan_P]

Mine is doing the same.
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Nice observation. What are you feeding and how much? I may do some calculations and a second example would be useful.

 

[taricha]

YoYo Nitrate Level

I use the Hanna ULR P Checker to measure the color intensity of the Red Sea nitrate test.



Tonight I started feeding half the number of mussels to see if the NO3 level zeros out.

You're my hero. For another experiment I was about to mix up known no3 concentration solutions from .5 to 20ppm to run the results of my Red Sea test through a colorimeter at 565 nm then use the data to make a calibration curve to do just what you did.
What no3 maxes out the Hanna ULR P test?

 

[Dan_P]

You're my hero. For another experiment I was about to mix up known no3 concentration solutions from .5 to 20ppm to run the results of my Red Sea test through a colorimeter at 565 nm then use the data to make a calibration curve to do just what you did.
What no3 maxes out the Hanna ULR P test?

For the exact number, I'd have to check my notes. Roughly, the ULR Checker tops out at 1-2 ppm NO3. The LR PO4 Checker will have a maximum near 10 ppm. The Total Chlorine Checker might get you to 20 ppm. Each increase in maximum value though diminishes the minumum you can detect though.

 

[taricha]

For the exact number, I'd have to check my notes. Roughly, the ULR Checker tops out at 1-2 ppm NO3. The LR PO4 Checker will have a maximum near 10 ppm. The Total Chlorine Checker might get you to 20 ppm. Each increase in maximum value though diminishes the minumum you can detect though.

I'm interested in 5-10ppm range mostly. So I could dilute 10:1 perhaps.
I'm reading through your old posts (you have the most interesting experiments) . Is there a thread where use of red sea no3 reagents with Hanna checker is hashed out? If not, I'll take it to pm.

 

[timnem70]

Nice observation. What are you feeding and how much? I may do some calculations and a second example would be useful.

Rods. Mysis. Clam. Pellets. Assorted daily and 3x week add reef roids or coral frenzy and broadcast.

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[bertoni]

The accumulation of nitrate was pretty quick. The implication is that ammonia production and subsequent ammonia oxidation can be quick. I thought things progressed somewhat more slowly after feeding. I need to ponder this observation a little longer.

I've been thinking about that, too. Maybe a lot of bacterial consumption of remains? That could be quick. I would have expected fish digestion to be slower.

 

[Dan_P]

I'm interested in 5-10ppm range mostly. So I could dilute 10:1 perhaps.
I'm reading through your old posts (you have the most interesting experiments) . Is there a thread where use of red sea no3 reagents with Hanna checker is hashed out? If not, I'll take it to pm.

Here's what I do with the Red Sea NO3 test for a 10 mL sample. Let me know if you need further information or clarification.

1-Add 0.16 mL liquid Reagent 1 to the 10 mL sample in the Red Sea test vial.
2-Add 0.1 mL powder Reagent 3 to clean, empty Hanna vial. I use the 0.05 mL red scoop from a Salifert test kit
3-Add 0.1 mL powder Reagent 2 to the test sample and shake vigorously for 1 minute only. It seems that the intermediate formed in this step is not stable.
4-Using a 0.2 or 0.4 micron syringe filter that is compatible with acid, not nylon, (I bought mine through Amazon), filter the sample into the Hanna vial containing Reagent 3 and mix. Hold for 9 minutes. Don't skip the filtration. Beside removing particulate matter, the filter removes carryover of solids into the second reactions which often diminishes the color intensity. This might not be visible to the naked eye but is definitely measurable.
5-Zero the Hanna Checker with an RO/DI blank (C1). Be sure to confirm before the test that the blank vial and the test vial are matched. Most Hanna vials are. Then take the reading of the developed test sample (C2).

 

[Dan_P]

Rods. Mysis. Clam. Pellets. Assorted daily and 3x week add reef roids or coral frenzy and broadcast.

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Thanks!

 

[Dan_P]

I've been thinking about that, too. Maybe a lot of bacterial consumption of remains? That could be quick. I would have expected fish digestion to be slower.

I was thinking. These mussels can cloud up the water and the skimmer makes a very stiff foam. So, possibly the nitrate jump is the bacterial consumption of the juices. If I clean off more of the slime, this might reduce nitrate spike.

 

[taricha]

Thanks for awesome test info.
If you knew actual amounts and what you are feeding, we could ballpark the total N content of the food input (16% of protein = N approximately) and compare the N input to how much actually shows up as NO3.
I did this for my tank and came up with daily food input of .7 to .9 ppm no3 which seems similar scale to what you are observing. But I wonder if what you are putting in may be far more than that, but this is only the portion that reaches a testable form.

 

[Dan_P]

Thanks for awesome test info.
If you knew actual amounts and what you are feeding, we could ballpark the total N content of the food input (16% of protein = N approximately) and compare the N input to how much actually shows up as NO3.
I did this for my tank and came up with daily food input of .7 to .9 ppm no3 which seems similar scale to what you are observing. But I wonder if what you are putting in may be far more than that, but this is only the portion that reaches a testable form.

I did the following in my head today.

An increase of 0.5 ppm NO3 in a 185 L system corresponds to adding ~93 mg of NO3. This amount of NO3 corresponds to about 23 mg of N. If biomass contains 7% nitrogen, then roughly 300 mg was digested, maybe more if some N was assimilated by the organism. But this is dry weight. Assuming 80% water content, the ballpark biomass digested is 1.5 g. I haven't weighed the washed mussel meat yet to see how the two numbers compare. If the mussel meat was 5-10 g, I would be impressed that this simple calculation was within an order of magnitude.

 

[bertoni]

That's interesting. Please let us know what the scale says!

 

[Dan_P]

That's very cool. How are you measuring tenths of a ppm no3?
Looks like if you skipped a day feeding, the algae would have the nitrate zeroed completely.

Two days after feeding one mussel instead of two, the nitrate level is undetectable