Just go to
广州市荔湾区越和花鸟鱼虫市场
You will amaze on how big is the place. Just like our wet markets but 20x bigger. got A, B and C zone. I think Zone C is for online shop warehouse and wholesalers, go to zone B and A more for walk in customers. Got very nice fish tanks, look for Boyu, jebao main stores... they are there....
There is a few shops that sell marine fishes. ..
If you know what you want, better to print the model and the picture of the equipment, it will make communication simpler.
you need spent more than half a day...