Phosphate Absorption of Aragonite Over Time

[jda]

Theory:
Aragonite will bind more than 500x the water column level when used in typical tank proportions. The aragonite will bind in an exponential fashion binding more as the water column level increases.

Setup:
10L of Water - IO salt, 1.026, 7.0 dKh, Hannah ULR Phosphorous 0 ppb, Temp 62.8 F, I could not find any other of my test kits
1KG Carib Sea Special Grade Reef Sand
Reactor
500ml of TSP Solution (10g of TSP in 500ml of water)
Hannah Ultra Low Phosphorous
Quiet One 800 Pump

Work So Far:
10g of TSP in a 500ml Water Bottle..

1 kg of Araonite in the Reactor. Had to do 4x 250g since the container would not hold a full kg.

10 L container, filled full and then marked after the reactor filled with water. This mark will be used to add RO for top off.

Process:
I used all new stuff, just things that I had. I do not have a lab, so something will get contaminated eventually, but this is the best that I can do.

Put 10g of the TSP (or whatever it is) into a 500ml water bottle to make a phosphate stock solution (PSS). Need to assume that this is 500ml, but it probably is not.

Got 10L of water from my salt water bucket. Tested it - results above. Put in 1ML of the PSS into the 10L. Mixed for about 5 minutes with the powerhead. Decided to test 3 times since this a baseline. I got 18, 20 and 21 on my Hannah ULR. Put in 9 more MLs, mixed again and got 177, 178 and 178. Going to use 10ml going forward and use 178 each time that I do.

Put the reactor and pump and fired it up.

Anecdotes and Things That I Cannot Account For:
I don't have precise equipment, so these measurements are rough.

I remove 20ml of water a day to test and will replace with 20ml of fresh saltwater, but I have no way to replace the po4 lost in the 20mls to the hannah test.

The powerhead will probably increase the temp a degree or two, so I will test and report moving forward. This is just in my finished basement and temperature can change if we open doors or windows.

I don't have a heater small enough to fit into this space, so will have to go without. There is plenty of evidence that 78 degrees will bind more, but that will be a different experiment for a different day... or I can add one at the end (if I order or buy a smaller heater) and see how the final numbers move with more heat.

I tried to keep my hands out of the water, but something probably got in there. Some film or bacteria might start to grow eventually. I cannot even use any copper since the aragonite will just bind it. If somebody has something that will keep organics from growing that will 1). not bind to aragonite and 2). not interfere with the test, I can get some and add.

I have no way to test pH. I have not cared about pH in a decade, or more, so I don't even have a pH pen that works.

Going Forward:
Will test at 1 hour to see how much the stock 178 ppb of po4 got lowered quickly.

Will test again every day at about noon, or as much as I can. Then, add 10 more ML of the PSS.

Keep a running total.

Hit me up if I need to change any of this, or redo anything.

The Whole Little Setup:

 

[jda]

After about an hour 139 ppb. 22% reduction in about an hour. I might test again later tonight.

A few things that I forgot...
I weighed the aragonite and then rinsed it out with RO. I am sure that we lost a few grams of dust. I have no way to measure this.

I will keep a google sheet of the numbers.

I kept the numbers clean for you science and numbers guys. I could not find a 1L water bottle in my house, so sorry about the 500 there. At least it is better than teaspoons and gallons, right?

 

[pledosophy]

Very Cool Excited to watch.

 

[Dan_P]

Theory:
Aragonite will bind more than 500x the water column level when used in typical tank proportions. The aragonite will bind in an exponential fashion binding more as the water column level increases.

Setup:
10L of Water - IO salt, 1.026, 7.0 dKh, Hannah ULR Phosphorous 0 ppb, Temp 62.8 F, I could not find any other of my test kits
1KG Carib Sea Special Grade Reef Sand
Reactor
500ml of TSP Solution (10g of TSP in 500ml of water)
Hannah Ultra Low Phosphorous
Quiet One 800 Pump

Work So Far:
10g of TSP in a 500ml Water Bottle..

1 kg of Araonite in the Reactor. Had to do 4x 250g since the container would not hold a full kg.

10 L container, filled full and then marked after the reactor filled with water. This mark will be used to add RO for top off.

Process:
I used all new stuff, just things that I had. I do not have a lab, so something will get contaminated eventually, but this is the best that I can do.

Put 10g of the TSP (or whatever it is) into a 500ml water bottle to make a phosphate stock solution (PSS). Need to assume that this is 500ml, but it probably is not.

Got 10L of water from my salt water bucket. Tested it - results above. Put in 1ML of the PSS into the 10L. Mixed for about 5 minutes with the powerhead. Decided to test 3 times since this a baseline. I got 18, 20 and 21 on my Hannah ULR. Put in 9 more MLs, mixed again and got 177, 178 and 178. Going to use 10ml going forward and use 188 each time that I do.

Put the reactor and pump and fired it up.

Anecdotes and Things That I Cannot Account For:
I don't have precise equipment, so these measurements are rough.

I remove 20ml of water a day to test and will replace with 20ml of fresh saltwater, but I have no way to replace the po4 lost in the 20mls to the hannah test.

The powerhead will probably increase the temp a degree or two, so I will test and report moving forward. This is just in my finished basement and temperature can change if we open doors or windows.

I don't have a heater small enough to fit into this space, so will have to go without. There is plenty of evidence that 78 degrees will bind more, but that will be a different experiment for a different day... or I can add one at the end (if I order or buy a smaller heater) and see how the final numbers move with more heat.

I tried to keep my hands out of the water, but something probably got in there. Some film or bacteria might start to grow eventually. I cannot even use any copper since the aragonite will just bind it. If somebody has something that will keep organics from growing that will 1). not bind to aragonite and 2). not interfere with the test, I can get some and add.

I have no way to test pH. I have not cared about pH in a decade, or more, so I don't even have a pH pen that works.

Going Forward:
Will test at 1 hour to see how much the stock 178 ppb of po4 got lowered quickly.

Will test again every day at about noon, or as much as I can. Then, add 10 more ML of the PSS.

Keep a running total.

Hit me up if I need to change any of this, or redo anything.

The Whole Little Setup:

Definitely a clean set up. Don’t worry about loss of phosphate from system when taking samples. That can all be corrected post experiment. Just keep track of the stuff taken out versus in. What about evaporation? Are you covering the tank?

 

[MnFish1]

Nice description and write-up

 

[taricha]

Nice.
@jda once you get a few days under your belt to establish the trend with this run, would be excellent if you flushed everything out and run it exactly the same but with no aragonite in the reactor.

 

[MnFish1]

Nice.
@jda once you get a few days under your belt to establish the trend with this run, would be excellent if you flushed everything out and run it exactly the same but with no aragonite in the reactor.

So you mean a control?

 

[jda]

Had to regroup. Tested last night (after about 8 hours) and again this morning and my Hannah ULR could not even detect the number - flashes 200 and the vial is as blue as snow-cone syrup.

I can only come up with 2 reasons why.

1). I did not let the TSP mix/dissolve long enough - whichever is the correct term.
2). The aragonite in the reactor has a bunch of po4 bound to it already. This seems less likely with the initial decline yesterday. Even if it had some bound po4, enough to get a water level over about .6 ppm does also not seem likely.

I tested each reading yesterday 3 times, so this was not a Hannah ULR error. The 500ml bottle is clear with no residual in the bottom. I shook it well each time before use.

In any case, I rinsed another kilo of aragonite, dumped the water, cleaned everything and restarted with fresh 10L of water but only one 1ml of the stock solution this time. I will test again this evening and see what happens.

I have to open a new box of Hannah reagent. Different lot. We are going to have to assume that they know what they are doing, which seems reasonable.

 

[Garf]

Had to regroup. Tested last night (after about 8 hours) and again this morning and my Hannah ULR could not even detect the number - flashes 200 and the vial is as blue as snow-cone syrup.

I can only come up with 2 reasons why.

1). I did not let the TSP mix/dissolve long enough - whichever is the correct term.
2). The aragonite in the reactor has a bunch of po4 bound to it already. This seems less likely with the initial decline yesterday. Even if it had some bound po4, enough to get a water level over about .6 ppm does also not seem likely.

I tested each reading yesterday 3 times, so this was not a Hannah ULR error. The 500ml bottle is clear with no residual in the bottom. I shook it well each time before use.

In any case, I rinsed another kilo of aragonite, dumped the water, cleaned everything and restarted with fresh 10L of water but only one 1ml of the stock solution this time. I will test again this evening and see what happens.

I have to open a new box of Hannah reagent. Different lot. We are going to have to assume that they know what they are doing, which seems reasonable.

I got a jump of 0.1ppm when changing batches of reagent on the Hanna LR.

 

[jda]

They were the same - 127. I just cannot read. It would not matter anyway since I started over.

 

[jda]

I had to regroup. My numbers were rising for a few days and I had no idea why.

I put 1ml of the solution into the 10l of water and it was instantly about 20, then 148 in about 24 hours and then over 200 (error on the hannah) after 48 hours. There was nothing in the container but the pump.

I worried that the container was releasing phosphate. I put in fresh seawater and it was 0, 1, 0 after 24 and 48 hours with just the pump in there.

It seems that the TSP takes time for a max reading? Is this reading real, or was the initial reading real, or somewhere in between?

I put 1/2 ml into fresh 10l of water and will see how far this goes. I will test later today, then tomorrow and every day after until the numbers settle out.

I am open to other suggestions, or that I am doing something wrong, but if it takes TSP days for a hannah to report accurately, then that changes a lot of things that people have been testing...

 

[Rams]

Love this

 

[happyhourhero]

I think this is the root for a huge chunk of new tank dino outbreaks. No one is telling new hobbyists to be prepared to dose phosphates and ensure it doesn’t bottom out while their dry rocks are soaking it all up.

 

[Rick Mathew]

I had to regroup. My numbers were rising for a few days and I had no idea why.

I put 1ml of the solution into the 10l of water and it was instantly about 20, then 148 in about 24 hours and then over 200 (error on the hannah) after 48 hours. There was nothing in the container but the pump.

I worried that the container was releasing phosphate. I put in fresh seawater and it was 0, 1, 0 after 24 and 48 hours with just the pump in there.

It seems that the TSP takes time for a max reading? Is this reading real, or was the initial reading real, or somewhere in between?

I put 1/2 ml into fresh 10l of water and will see how far this goes. I will test later today, then tomorrow and every day after until the numbers settle out.

I am open to other suggestions, or that I am doing something wrong, but if it takes TSP days for a hannah to report accurately, then that changes a lot of things that people have been testing...

Ok...just for clarity purposes here is what I understand you did....1) You mixed up a solution of Na5P3O10 (Sodium tripolyphosphate) using 10 grams to .5l. ...This should yield somewhere in the range of 1700 ppm P (1700000 ppb). 2) You then used 1mL of that solution in 10l of water....that should give you somewhere around .17 ppm P...If all my math is correct...This is 170 ppb P which you Hanna Checker measures (ppb)...This would be the range of the measurement I would have expected based on what you are reporting (about 170+ppb Phosphorus,But your measurement yielded first 20 ppb then 148ppb in 24 hours and then too high to measure 200+ ...Do I have this correct?

 

[Randy Holmes-Farley]

I had to regroup. My numbers were rising for a few days and I had no idea why.

I put 1ml of the solution into the 10l of water and it was instantly about 20, then 148 in about 24 hours and then over 200 (error on the hannah) after 48 hours. There was nothing in the container but the pump.

I worried that the container was releasing phosphate. I put in fresh seawater and it was 0, 1, 0 after 24 and 48 hours with just the pump in there.

It seems that the TSP takes time for a max reading? Is this reading real, or was the initial reading real, or somewhere in between?

I put 1/2 ml into fresh 10l of water and will see how far this goes. I will test later today, then tomorrow and every day after until the numbers settle out.

I am open to other suggestions, or that I am doing something wrong, but if it takes TSP days for a hannah to report accurately, then that changes a lot of things that people have been testing...

I cannot see how it takes any time for dissolved phosphate to become detectable.

 

[Randy Holmes-Farley]

Wait, are we talking about trisodium phosphate, or a polyphosphate mentioned above? The latter may need to break down before being fully detectable.

 

[Rick Mathew]

Wait, are we talking about trisodium phosphate, or a polyphosphate mentioned above? The latter may need to break down before being fully detectable.

The picture shown is polyphosphate (Na5P3O10)...

 

[jda]

Rick - all that you said was correct. The values just keep rising over time and I wanted to see when they would stop. I am currently at .5ml in the 10l. I am going to test again tonight. ...so we should be around 85 ppb if your math is correct, give or take, when it is all said and done? Unfortunately, my tool stops at 200 ppb, so I am limited.

I was able to determine that the container and pump are at least phosphate free and that no phosphorus was detected after about 48 hours of fresh seawater just running through the container.

I just want to get a baseline so that every time I add X mls, I know that I added about Y of phosphorous.

 

[jda]

I just tested and about 24 hours after adding .5ml into the 10l, the Hannah shows over 200ppb.

I am going to have to make a weaker stock solution... maybe 1g instead of 10g into 500ml of water.

Does that 170 need to be multiplied by 3.066?

 

[Dan_P]

Rick - all that you said was correct. The values just keep rising over time and I wanted to see when they would stop. I am currently at .5ml in the 10l. I am going to test again tonight. ...so we should be around 85 ppb if your math is correct, give or take, when it is all said and done? Unfortunately, my tool stops at 200 ppb, so I am limited.

I was able to determine that the container and pump are at least phosphate free and that no phosphorus was detected after about 48 hours of fresh seawater just running through the container.

I just want to get a baseline so that every time I add X mls, I know that I added about Y of phosphorous.

It seems you are using the wrong reagent. You need to use trisodium phosphate.