PO4 is to low

[Jorge Frazoa]

Hello everybody!
I need your help.

I have had some problems with diatom algae. I had a recent ICP and the silica was very high (1007mg/l). My RODI has silica at 0.0 so I suspect that the silica was coming from the ceramics, but I already removed them.

Until now I was trying to control the nutrients with a carboo source, but I decided to put chaetomorpha in my refuge. The chaeto is only 1 week old and I notice that it has some white tips.

The big issue now is that I can't get PO4 readings on the Hanna checker, even dosing 0.16ppm per day. I dose Nyos phosphate +.

Do you think I should continue dosing this amount of PO4 per day? Do you think the diatoms are absorbing all the incoming PO4? or the rock?
Is it possible the chaeto is turning white due to the low PO4, even at 0.16ppm per day?

Parameters:
Po4 - 0.00 (Hanna Checker) / 0.018 (ICP)
No3 - 30 ppm
Magnesio - 1400
Cálcio - 424
Salinity - 1026
Silica - 1.007 mg/l
Aluminium - 170 ug/l
Thanks and sorry for my english.

 

[Icryhard]

If your Hanna Checker is returning 0 but the ICP test 0.018 I can't help but to wonder: Which checker do you have? The HR or the LR, ULR? On top of that, if you wish to fight diatoms, get something which removes silicates. When I did this, it finally stopped being a problem for me, and until then, since you do seem to have corals, keep up PO4 up a bit. If this bottoms out you could run into dino (and corals which start to die off).

 

[Jorge Frazoa]

Thanks for the answer.
I use the Hanna ULR (Hi774).
I have Sera Silicate Clear, but it is passive in the sump. What media did you use to reduce silicate?
Regarding PO4 I'm trying to increase it, I'm already dosing 0.16 ppm/day, but I still don't have readings.

 

[Randy Holmes-Farley]

I'd keep dosing phosphate, yes. Both values are low to OK, with no hint of phosphate being high. I might even up the dose.

 

[Jorge Frazoa]

I'd keep dosing phosphate, yes. Both values are low to OK, with no hint of phosphate being high. I might even up the dose.

Thanks so much for the reply, Randy.
I thought dosing 0.16 ppm a day was too much. Do you think I can increase it to how many ppm/day?

I have noticed a boom in diatoms since I increased the PO4 dosage. I think that the diatoms are also absorbing the dosed PO4, but I think that when they consume all the silica they end up dying. Or am I thinking wrong?

 

[Randy Holmes-Farley]

Thanks so much for the reply, Randy.
I thought dosing 0.16 ppm a day was too much. Do you think I can increase it to how many ppm/day?

I have noticed a boom in diatoms since I increased the PO4 dosage. I think that the diatoms are also absorbing the dosed PO4, but I think that when they consume all the silica they end up dying. Or am I thinking wrong?

Add as much as needed, IMO.

Foods are likely adding a similar amount each day, so it's not like a crazy addition.

Aquarium Chemistry: Phosphate And Math: Yes You Need To Understand Both

Foods are by far the most important source of phosphate in most aquariums. In considering whether sources of phosphate other than foods are important, one must carefully look to the actual amounts involved to determine whether other sources are even worth trying to minimize.

reefs.com

 

[Jorge Frazoa]

Add as much as needed, IMO.

Foods are likely adding a similar amount each day, so it's not like a crazy addition.

Aquarium Chemistry: Phosphate And Math: Yes You Need To Understand Both

Foods are by far the most important source of phosphate in most aquariums. In considering whether sources of phosphate other than foods are important, one must carefully look to the actual amounts involved to determine whether other sources are even worth trying to minimize.

reefs.com

Thanks so much Randy.

I'm going to increase it and I'm monitoring the PO4, I hope that with this I can bring the NO3 down.
In your opinion, do you think the chaeto could have white tips due to the little PO4 available? Or does it use, together with the diatoms, all the PO4 that I am dosing and what goes into the food?

Thanks

 

[Randy Holmes-Farley]

Thanks so much Randy.

I'm going to increase it and I'm monitoring the PO4, I hope that with this I can bring the NO3 down.
In your opinion, do you think the chaeto could have white tips due to the little PO4 available? Or does it use, together with the diatoms, all the PO4 that I am dosing and what goes into the food?

Thanks

I don't know if it is getting all it wants and it might grow better with more.

It might also benefit from an iron and manganese trace element supplement. Those two deplete rapidly.

 

[Jorge Frazoa]

Não sei se está conseguindo tudo o que quer e pode melhorar com mais.

Ele também pode se beneficiar de um suplemento de oligoelemento de ferro e manganês. Esses dois se esgotam rapidamente.

Obrigado mais uma vez, tem sido implacável.

Duas vezes por semana eu doso o componente ABC, que contém todos os oligoelementos.

Depois de atingir a PO4 desejada, reduzo a dose diária ou espero que volte a cair?

 

[Randy Holmes-Farley]

After reaching the desired PO4, do I reduce the daily dose or wait for it to drop again?

You may need to dose it every day.

 

[Jorge Frazoa]

You may need to dose it every day.

Thanks a lot, Randy.

I know I can make a homemade phosphate solution, can you help me with that?

Thanks

 

[Jorge Frazoa]

@Randy Holmes-Farley , you have been amazing and you have helped me a lot.

I want to make my own phosphate but I have some doubts.

If I follow your formula and add 1.88gr of trisodium phosphate to 1lt/RODI, I end up with a solution that allows you to increase 0.01ppm in 100 liters, right?

Is it possible to increase the concentration, for example 5gr of Na3Po4 in 1lt of RODI?
Or is there a risk of saturating and not diluting all the trisodium phosphate?

Once the solution is made, can it evaporate or lose its concentration over time?

Thank you and sorry for so much doubt

 

[Jorge Frazoa]

Randy, is there any difference in dosages between Na3Po4 and Na3Po4-12H2O?
Which one do you think is better for phosphate DIY?

 

[KStatefan]

The mass required to mix with water to be the same concentration of PO4 will be different.

 

[Jorge Frazoa]

The mass required to mix with water to be the same concentration of PO4 will be different.

Thanks.
For trisodium phosphate (Na3Po4), according to the @Randy Holmes-Farley , 1.88g per liter were needed. And if it is trisodium phosphate dodecahydrate (Na3Po4-12H20), how many grams should I use per liter?

Thanks

 

[KStatefan]

Thanks.
For trisodium phosphate (Na3Po4), according to the @Randy Holmes-Farley , 1.88g per liter were needed. And if it is trisodium phosphate dodecahydrate (Na3Po4-12H20), how many grams should I use per liter?

Thanks

Your image shows molecular weight of 380 g/mole for the Na3PO4-12H2O and Na3PO4 is 165 g/mole so it has 2.3 times mass for the same PO4 content. so 2.3 x 1.88 g = 4.3 g

I know nothing about Na3Po4-12H20 if it is a good product for dosing phosphate

 

[Jorge Frazoa]

Sua imagem mostra o peso molecular de 380 g/mol para o Na3PO4-12H2O e o Na3PO4 é 165 g/mol, portanto tem 2,3 vezes a massa para o mesmo conteúdo de PO4. então 2,3 x 1,88 g = 4,3 g

Não sei nada sobre Na3Po4-12H20 se for um bom produto para dosagem de fosfato

Thank you very much

I'm going to try to find only Trisodium Phosphate. But in Portugal I am only managing to find this formula. But I think I've already seen, somewhere, a publication by Randy with this information, where there was no problem making phosphate with Na3Po4-12H20, but you had to double the amount, and it matches those calculations.

Thank you very much

 

[Randy Holmes-Farley]

The water in the sodium phosphate crystals is not any problem ;if you account for the potency). Purity is more important.

Do these materials indicate purity?

 

[Jorge Frazoa]

The water in the sodium phosphate crystals is not any problem ;if you account for the potency). Purity is more important.

Do these materials indicate purity?

Thanks a lot for the answers.

Yes, @Randy. I asked before buying and the seller says it is >99% pure. They gave me a code to check the product sheet, but it doesn't mention the purity. The code is CAS: 10101-89-0. I've been searching and just found this: photo attached.

Thank you very much

 

[Randy Holmes-Farley]

CAS (chemical abstracts service) numbers identify the chemical, but say nothing about purity.