Project 6ft

phew project 6ft is finally running .but only on a jbl 701 filter which only does 200l. because every all pond solutions filter 2000ef+.has turned up with problems,lightswitches broke bulbs busted,broke clips.then the new one that turned up shorts my electric every time i put it on lol.but onwards i go just wondering what my stock limit can be i want malawi cichlids can anyone help please my tank is 6x2x2

thanks so im thinking about 60 odd fish to stock the tank malawi set up.but i have been told to add more though.