Questions pH UP homebrew?

@dr-jitter-bug, Silica will raise it. But I don't know a readily available DIY substitutes. 

Wood ash but not treated wood, (Baking soda) or not, lol, Limestone (tiny amounts)

@woodi2 Thanks! I wonder if there is a water soluble form of silica out there?

@zn First - love the pod! Second, I've tried wood ash but have probably been too sparing as I've not seen much of an effect. How much would you recommend per 4L of solution at a pH of 5.5?

I mean... maybe some silica desiccant?

@dr-jitter-bug, at the hydro store. But it a bottled liquid. I don't know if that's what your looking for. 

Posted by: @dr-jitter-bug

@zn First - love the pod! Second, I've tried wood ash but have probably been too sparing as I've not seen much of an effect. How much would you recommend per 4L of solution at a pH of 5.5?

Thanks...we love it too

Best way to apply it is to dissolve in water and leave overnight, I dont know the exact measurements but start with 20g in the 4l and measure Ph after 24hours, this will give you an idea of what to use...

Potassium bicarbonate is a decent substitute for baking soda and the substitution of potassium over sodium is a plus for the plant too. It is commonly used as an antacid for humans, is cheap and easy to source too. Personally I’d not go the silica route. While silica amendments will raise ph it will also cause other issues if it’s over used. 
Ive used wood ash in mixing soils but have not attempted to use it in hydro. It is very strong stuff and might hold some promise 

@zn Excellent, thanks again!