I am really trying to get past the “bathtub” chemist mentality that we all sometimes exhibit when we provide info in general terms.
When you say a bit of phos acid can you clarify that?
Say I am making a 1 gal batch of OA and using about 1 cup OA to get a 4% solution. How much phos acid would you add? What about surfactant?
I really hate just mixing things in what feels like a random manner without some sense of what it is I am doing, what I am trying to achieve and a valid starting point. I do my fair share of “bathtub” chemistry but usually it starts with some reference point and then calculated measurements of each item to reference with results and adjust accordingly.
On the issue of solubility of OA Powder into water. Everything I am researching indicates that warm to hot water in the standard when mixing the two. I even rigged up a 12 volt kettle to boil water from my softwash system on-site to mix OA when needed or make coffee in the morning (be sure not to mix your solution in the kettle - only boil water and pour into another container for mixing otherwise making coffee with OA might lead to some self poisoning).