Hi

I'm from Singapore and we have a local lab here which formulates
decent-priced macro and micro nutrients for aquariums. Their website is
http://www.singaporehydroponics.com and their products are commonly
found in our local aquarium stockists. I'm not sure if they ship
worldwide but you could give them a try.

The products I'm using now are LushGro Aqua (dosed after weekly partial
water changes) and LushGro Micros (dosed daily). My plants are growing
superbly and I've been using these cheap alternatives (as compared to
SeaChem supplements) since 2003.

Regards