The tank has been setup for a month BUT i transferred used gravel, ornaments & decorations from a previous tank plus my eheim 2213 was cycled from the previous tank hence it was cycled in 24 hours and maintained stability.
Water parameters:
ammonia: 0
nitrite: 0
nitrate: 3
pH: 7.4
According to another forum, it turned out to be Dwarf Gourami Iridovirus.
He was not eating and was fading fast.
He was euthanized this morning.