Sanity check for mixing phosphate solution

[nim6us]

I’ve been making my own solution that I dose to raise phosphate for a year or so now. The company I usually order from was out of stock so I had to order my monopotassium phosphate from another source.

The issue is my normal dosing amount after I mix up the solution isn’t increasing my phosphate levels. I even mixed up a second batch thinking I did something wrong but it’s still not raising phosphates.

I used the James Planted Tank calculator to get my measurements. And nothing had changed since my last batch of solution except my potassium phosphate source. Can someone who understands chemistry a bit better than I look at the label and see if there’s an indication that this is perhaps less potent?

 

[Biglew11]

I’ve been making my own solution that I dose to raise phosphate for a year or so now. The company I usually order from was out of stock so I had to order my monopotassium phosphate from another source.

The issue is my normal dosing amount after I mix up the solution isn’t increasing my phosphate levels. I even mixed up a second batch thinking I did something wrong but it’s still not raising phosphates.

I used the James Planted Tank calculator to get my measurements. And nothing had changed since my last batch of solution except my potassium phosphate source. Can someone who understands chemistry a bit better than I look at the label and see if there’s an indication that this is perhaps less potent?

We would need to know both sources of potassium.

 

[nim6us]

Yeah as soon as I posted it I knew someone would ask that. I bought my original one in bulk and I can't find the brand that produced it offhand, I'll try and dig it out.

However, let me rephrase; based on the monopotassium phostphate source I shared in my original picture if I used James' Planted Tank - Dosing Calculator to calculate "Phosphate- from Potassium Phosphate" should I expect to get an accurate dosing solution?

 

[KStatefan]

I do not use that form of phosphate I am using trisodoum phosphate or Sodium Phosphate Dibasic and my current dose is 0.06 ppm per day and struggle to get above zero. How much are you dosing?

 

[nim6us]

This is for a frag tank and the calculation I used is...

I have a pump-bottle that doses 2ml per pump, so I made my math off of that to raise .03ppm per dose.

At the risk of tangentializing this is another question I had. In the calculator it just says "Potassium Phosphate" but looking into it there are actually three kinds:

• Monopotassium phosphate (KH2PO4)
• Dipotassium phosphate (K2HPO4)
• Tripotassium phosphate (K3PO4)

It is not implied which source is used to make the calculator, and if I'm honest I don't know the benefit of using one over the other.

 

[nim6us]

Sorry to summon you @Randy Holmes-Farley I know you're a busy man.. any thoughts?

 

[Randy Holmes-Farley Verified Community Expert]

There’s nothing in the label that indicates any issue. I’d dose more and see what happens.

 

[nim6us]

That’s all I needed to know, thanks for the assessment!

 

[nim6us]

Okay with a little more rigor on my third attempt, surprise surprise, it was human error.

I threw everything into my beaker and let it mix with my magnetic stirrer for a roughly 30min as always do. But before I poured the solution into my container I held it up to a bright light source and the mono phos granules were very fine but not fully dissolved. The granules are so small and so clear it was easy to overlook.

I threw the beaker back on the stirrer but I dialed it up to 11! Checked again after 15min and the solution was fully mixed. I dosed, tested, and it was bang on where it should be.

Uggh, so embarrassing... but I hope sharing this helps someone else.

 

[Randy Holmes-Farley Verified Community Expert]

Glad things worked out!