The myth of N an P trapped on the sand bed

[sixty_reefer]

The ability of home test kits to extract total nitrogen and phosphorus from organics is what I’m finding interesting

total phosphates from sand and organics on the right, total organics and inorganic from the water column on the left

total phosphates from the organics trapped on the sand only

the question here is if I am able to filter organics from the water column, would I have less than 0.1 ppm phosphates available in my tank. Making it a DIY test to separate organic phosphates from inorganic phosphate. What kind of filter would I need to remove organics from the water column @Randy Holmes-Farley?
If my assumption is correct we should be able to test for organic and inorganic N and P at home by applying a specialised filter.
Calculate the total phosphates and reduce it from the phosphates tested with a special filter that should test for inorganic only.

what this thread may be starting to show is that organics in the water column can affect the accuracy of home test kits, if there is many micro algaes floating on the water column, like the ones we see on our glass they may be affecting the results greatly as our test kits have the ability to break them down and show them as phosphates or nitrates. The development of a filter for our syringe should aid to remove this variables and differentiate organic phosphates from inorganic phosphates.

 

[Randy Holmes-Farley]

The ability of home test kits to extract total nitrogen and phosphorus from organics is what I’m finding interesting

total phosphates from sand and organics on the right, total organics and inorganic from the water column on the left

total phosphates from the organics trapped on the sand only

the question here is if I am able to filter organics from the water column, would I have less than 0.1 ppm phosphates available in my tank. Making it a DIY test to separate organic phosphates from inorganic phosphate. What kind of filter would I need to remove organics from the water column @Randy Holmes-Farley?
If my assumption is correct we should be able to test for organic and inorganic N and P at home by applying a specialised filter.
Calculate the total phosphates and reduce it from the phosphates tested with a special filter that should test for inorganic only.

what this thread may be starting to show is that organics in the water column can affect the accuracy of home test kits, if there is many micro algaes floating on the water column, like the ones we see on our glass they may be affecting the results greatly as our test kits have the ability to break them down and show them as phosphates or nitrates. The development of a filter for our syringe should aid to remove this variables and differentiate organic phosphates from inorganic phosphates.

I don’t believe ordinary test kits will detect much N and P that is organic. No N and maybe just a little P. You needs a tedious digestion step for that. Hach sells a total P kit.

 

[J1a]

That’s my thoughts as well, and the centre of the thread. I didn’t knew that our home test kits could potentially have the ability to dissolve organics in the vials and make them available to interpret in ppm on a test kit.
this could also indicate that wend we test out water column we could potentially be testing for organic nutrients in the water column and not just inorganic nutrients as we always believed we where doing.
I don’t know about you, but it makes me think that the accuracy of the test at home could be influenced depending on the organics on the water colum.
Example. Testing phosphates after dosing phytoplankton could in a way affect the accuracy of the test as it may break down the phytoplankton in the vial and make those phosphates show as inorganic nutrient making us believe that there is more phosphates that we actually have. Same if we were to test after feeding etc…

Phyto culture is rather meddlesome as well. Most of them are laden with nitrate and phosphate. It much more likely for test kits to pick those up, rather than phyto breaking down.

 

[sixty_reefer]

I don’t believe ordinary test kits will detect much N and P that is organic. No N and maybe just a little P. You needs a tedious digestion step for that. Hach sells a total P kit.

I see what you mean, some of the results I see kind of make me believe that all test kits may not be equal.

 

[sixty_reefer]

Phyto culture is rather meddlesome as well. Most of them are laden with nitrate and phosphate. It much more likely for test kits to pick those up, rather than phyto breaking down.

I wasn’t referring to the phytoplankton we culture, I was thinking of the phytoplankton that grows naturally in our systems. Most often observed as a green film on the glass surfaces.

 

[sixty_reefer]

My test kit got the potential to be different some how.
I thought it would beneficial for me to follow my instinct, I’ve performed 2 test on my phytoplankton culture one is filtering the phytoplankton with a paper towel (all I had to hand) until the culture brine runs clear and on another vial just add phytoplankton culture straight including the live algae.
Both samples were diluted in the same percentage.

With my test kit appears that micro algaes will influence the overall results of the test.
the camera can capture that the vial on the right is slightly darker than the vial to the left.

 

[sixty_reefer]

And lastly my tank, this time filtered with two cotton pads, I feed my system constantly phytoplankton, the difference is not much maybe around 0.02 ppm to 0.03 ppm and wouldn’t create a large issue as I run my system at 0.1 ppm. The story could be different if I was to run my system at 0.02 ppm.

is this the reason we have to allow for a 0.02 ppm error margin in some test kits?

 

[MnFish1]

IMHO - siphoning from the sand bed - and then filtering the water (with whatever innocuous) would take away any problems with the testing. However - I wish you had posted this to the experimentation section

 

[sixty_reefer]

I don’t believe ordinary test kits will detect much N and P that is organic. No N and maybe just a little P. You needs a tedious digestion step for that. Hach sells a total P kit.

This one? https://uk.hach.com/test-kit-phosph...odel-po-24/product?id=25114225339&callback=qs

 

[MnFish1]

This is very interesting - and gets to a point I tried to make with Aquabiomics. Depending on where you 'sample from' - you will get different results. It's the same here IMHO. Tests with ranges of xyz are not probably designed to test water in different conditions. Thus you will get different readings. For example - let pretend in the main tank water - the nitrate is 5. But sucking out of the sand its 30. So what?

 

[sixty_reefer]

This is very interesting - and gets to a point I tried to make with Aquabiomics. Depending on where you 'sample from' - you will get different results. It's the same here IMHO. Tests with ranges of xyz are not probably designed to test water in different conditions. Thus you will get different readings. For example - let pretend in the main tank water - the nitrate is 5. But sucking out of the sand its 30. So what?

I’ve come to conclusion that there is more than just testing the sand bed.
My test kit seems that may be able to break down organics this means if I test the sand bed with it, will tell me how much organics are there before it breaks down to inorganic nutrients.
min the other hand as I test the water column there is a difference between filtering the water and not filtering the water. This means that this test kit in a way is testing total phosphates in the water column instead of just inorganics as I was set to believe the importance is that if I was to run my reef at 0.02 ppm phosphates I would have a chance of bottoming out my inorganic phosphates without realising it. As it appears that micro algaes in the water column are affecting the end results.

 

[MnFish1]

My test kit seems that may be able to break down organics this means if I test the sand bed with it, will tell me how much organics are there before it breaks down to inorganic nutrients.

This is a problem - you're using a test (of your sandbed) that is not designed to do so. Thus - any results you get are suspect.

 

[sixty_reefer]

This is a problem - you're using a test (of your sandbed) that is not designed to do so. Thus - any results you get are suspect.

I’ve performed a few different scenarios and they all keep indicating that the test is reliable with organics.

test on sand bed

test on organics from the sand bed (no sand)

test on filtered phytoplankton culture (no algae) and standard phytoplankton culture (includes algae)

test on my tank that gets 2 ml of phytoplankton every 60 min

from all the test I done so far it indicates that this test kit can break down organic phosphates. Only one test had sand in it.

 

[MnFish1]

I’ve performed a few different scenarios and they all keep indicating that the test is reliable with organics.

test on sand bed

test on organics from the sand bed (no sand)

test on filtered phytoplankton culture (no algae) and standard phytoplankton culture (includes algae)

test on my tank that gets 2 ml of phytoplankton every 60 min

from all the test I done so far it indicates that this test kit can break down organic phosphates. Only one test had sand in it.

Nitrate is not 'an organic'. Phosphate is not 'an organic'. Is there waste in the sandbed - yes.

 

[sixty_reefer]

Nitrate is not 'an organic'. Phosphate is not 'an organic'. Is there waste in the sandbed - yes.

If they are in the form of micro algae, left over food or detritus they are organic. It seems that this test kit can demineralise those organics and make them available in the test kit, I can only speak for this brand

 

[Randy Holmes-Farley]

This one? https://uk.hach.com/test-kit-phosph...odel-po-24/product?id=25114225339&callback=qs

Yes

 

[Randy Holmes-Farley]

If they are in the form of micro algae, left over food or detritus they are organic. It seems that this test kit can demineralise those organics and make them available in the test kit, I can only speak for this brand

I do not believe any hobby kit breaks down organic N. Some organic P may be released in a kit, but definitely not mist of it.

 

[sixty_reefer]

I do not believe any hobby kit breaks down organic N. Some organic P may be released in a kit, but definitely not mist of it.

Solution1: Hazard-determining component

Hydrochloride acid
Sulphuric acid
H302, h314, h335

solution 2: Hazard-determining component

Hydrogen chloride
h302, h314, h318, h335

from google I was able to find the safety data sheet and it mentioned this elements as reagents, my chemistry as you may have gathered is fairly week, is any of this able to break down organics on the phosphates reagents?

 

[Garf]

Solution 1:
Hydrochloride acid
Sulphuric acid

solution 2:
Hydrogen chloride
h302, h314, h318, h335

from google I was able to find the safety data sheet and it mentioned this elements as reagents, my chemistry as you may have gathered is fairly week, is any of this able to break down organics on the phosphates reagents?

Hydrochloric can certainly dissolve the sand which would free up any phosphate bound to it, hence the high result, but it’s not organic.

 

[Randy Holmes-Farley]

Solution1: Hazard-determining component

Hydrochloride acid
Sulphuric acid
H302, h314, h335

solution 2: Hazard-determining component

Hydrogen chloride
h302, h314, h318, h335

from google I was able to find the safety data psheet and it mentioned this elements as reagents, my chemistry as you may have gathered is fairly week, is any of this able to
break down organics on the phosphates reagents?

as I mentioned, acid will break down some organic P. I personally think there is some different explanation for mist of your result, including interference or partial detection of some organic phosphates.

Organics containing N will not be similarly broken down.