talaad thai has a large selection of cheap local foods. both powder and liquid.
if you go to the back of the garden section to the left (one of the biggest stores) they have a huge selection of nutrients.
best bring your wife as its all in thai on most of the bottles. happy hunting.
i am taking master grower there this weekend to see if we can find a formula that he would approve of.
will post details after i find out.