Question
"Hi,
I bought a bottle of water-soluble
fertilizer which is in powdery
form. I tried to dissolve it in water
as per instruction on it. But the
powder is not completely
dissolving in water. Residues are
left in the bottom of the mixing
container. Will it create any
concentration variation due to
improper mixing? because I am
afraid of burning the plants. Is
there any method to completely
dissolve it? Can I use hot water?
And whether applying on foliage
is more efficient or in to the soil?
Waiting to hear from you soon"

Answer
shafreej
Did you apply it as so many Ounces per gallon.?.What strength is it.?.5-10-5, 30-30-30,etc.?.Sounds like it may have been older fertilizer...
Get to your local garden center and buy new fertilizer for you indoor plant...It's not worth jeopardizing the health of your plants by applying an inferior/old plant fertilizer...
Hope this helps,
Rick in southern NJ USA