How to dose dry KH2PO4?

Yes for the just add this much water to...but I can't calculat it yet so I'd be guessing based on my 10g. And actually I do dose 1/64 tsp one week and 1/32 tsp the next.
But it will be regulated by your WC. As in once a week after the WC.
There are at least a couple of them on here who know a formula for it and I'm sure one will jump in before too long.

Or just buy a set of these measuring spoons:

Norpro 3080 Mini Measuring Spoons, 5 Piece Set

But how to dose 1/32 tsp? Impossible to calculate by naked eye...
Any formula to mix it with water?

Hi EvilFish,

The spoon set indicated above goes down to 1/64 teaspoon which happens to be the EI dose I use for my 10 gallon.

Before spending too much effort, there may be another factor to consider.
I found EI was a place to start but doing a 50% water change was not enough to keep my phosphate from creeping gradually higher and higher. Mine got off the charts before I found it. I got into an area where I had to do massive frequent water changes to get it back down. I no longer use ANY K2PO4. I get plenty from food or other sources. Maybe you don't really need to do the 1/32 measurement anyway?

Seattle_Aquarist said:

Hi EvilFish,

The spoon set indicated above goes down to 1/64 teaspoon which happens to be the EI dose I use for my 10 gallon.

Click to expand...

Nice. Ordered.