trisodium phosphate dont raise my po4...

[escaraba]

Hello folks,

II need to add po4 because it drops to 0 very quickly in my 5000L system.
I use this
I use 10gr in 1L ro water. so 1 ML would increase po4 with 0.01 in 100 L
If i measure this solution pure in a hanne chekker it reads even 0!!!

what am I missing here?
thx,

 

[Randy Holmes-Farley Verified Community Expert]

Can you explain more what you measured?

There's no scenario where enough trisodium phosphate will fail to raise the phosphate level, but it may take a lot more than calculated due to rock and sand binding.

 

[jda]

I have no idea why you cannot measure any phosphate in the stock solution.

Most of what you are doing ends up in the rocks and sand. Phosphate binds stongly to aragonite. If you keep adding, then eventually the rocks and sand will get moe "full" and more will stay in the water column - the araonine bind to a sort of equilibrium with the water around it.

Just know that if you ever want to remove that po4 from the rocks and sand, it can be a long and laborious process. The rock and sand can act like a buffer when levels are low making sure that you never truly bottom out, but they can also act as a reservoir when levels are high that is very hard to remove.

 

[exnisstech]

I'm not a chemistry guy but I couldn't get past Willem Defoe to even read about the product :thinking-face:

 

[escaraba]

Can you explain more what you measured?

There's no scenario where enough trisodium phosphate will fail to raise the phosphate level, but it may take a lot more than calculated due to rock and sand binding.

Thx for the replay,

I use a Hanna HI97115c Marine Master Set. HI774-25 reagens

i mix 10gr in 1L ro water
I take 10 ml to test
It read 0 after 3 min

I ask hanna and this is thare replay:

This is because this test only measures free phosphates, also called orthophosphates.
However, trisodium phosphate has a more complex structure and is also called condensed phosphate.
The test to measure phosphates will not detect trisodium phosphate.
For this you actually need a test that measures total phosphorus.
You will also be able to measure the trisodium phosphate.

 

[jda]

Wait a few days. It broke down into ortho for me in 3 days in an experiment. I am sorry that I missed this - I should have know.

 

[escaraba]

Wait a few days. It broke down into ortho for me in 3 days in an experiment. I am sorry that I missed this - I should have know.

I am battling over a month to raise it. just keep adding more till i get a reading?
I dose 50ml daily atm.

For no3 i take 140gr in 1L ro
I dose 45 ml to keep it at 4ppm

 

[jda]

Use caution. You could have added too much by the time that your readings start to appear. The polyphoshpate is usable by the corals and even is preferred by many in some studies. i would not assume just because you cannot test for it that phosphorous is not getting to the corals.

 

[Randy Holmes-Farley Verified Community Expert]

Thx for the replay,

I use a Hanna HI97115c Marine Master Set. HI774-25 reagens

i mix 10gr in 1L ro water
I take 10 ml to test
It read 0 after 3 min

I ask hanna and this is thare replay:

This is because this test only measures free phosphates, also called orthophosphates.
However, trisodium phosphate has a more complex structure and is also called condensed phosphate.
The test to measure phosphates will not detect trisodium phosphate.
For this you actually need a test that measures total phosphorus.
You will also be able to measure the trisodium phosphate.

lol

A other ridiculous answer from a hobby company.

It is utterly without merit. Trisodium phosphate is 100% orthophosphate.

Giving them the maximum possible benefit of the doubt, perhaps they confused trisodium phosphate with sodium tripolyphosphate.

 

[Randy Holmes-Farley Verified Community Expert]

Wait a few days. It broke down into ortho for me in 3 days in an experiment. I am sorry that I missed this - I should have know.

It is not a polyphosphate.

 

[jda]

I am going to disappear for a week, or so. My mind is gone. I used Sodium Tripolyphosphate - I had to look just now. (hangs head in shame) ...my apologies to all.

 

[Reefahholic]

Trisodium Phosphate sucks. I’ve used it many times in the past. It’s not very bioavailable at all. A pic is worth a thousand words. I have the data too.

Just look at the PO4 coming up when I switched products.

Note the bright green algae forming on the rocks, and on the back glass. If a system is binding enough, throw your TSP in the trash. It’s worthless.

View attachment 3548644

 

[Randy Holmes-Farley Verified Community Expert]

Trisodium Phosphate sucks. I’ve used it many times in the past. It’s not very bioavailable at all. A pic is worth a thousand words. I have the data too.

While I believe I disagree with your assertion that inorganic orthophosphate is not bioavailable, can you explain two things to add some words to these pictures.

1. What does bioavailable mean to you? Are there any corals in the aquarium?
2. What was actually added to these aquaria?
3. What does the algae say about bioavailability?

 

[Randy Holmes-Farley Verified Community Expert]

For those who can access it, this paper is a very good and highly detailed discussion about phosphate uptake by reef organisms:

https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1002/ecm.1217