Hi all,
I have a 200 litre (100 cm long, 50cm high, 30cm back) aquarium which has 6 harlequin rasboras, 9 rummeynose tetras, 4 SAEs and 7 Cardinal tetras. I have a Fluval U4 filter ( running on the top hose setting), 4 pieces of bog wood, and an Eheim heater ( the tank is normally 27-28 degrees...