I believe it depends on ur room temperature also... I don't switch on the air-conditioner, so room temperature usually 28ºC to 30ºC (sometimes higher during day time)
I am running the following pumps in my tank:
1. Aqua Medic PH2000 (skimmer)
2. Sicce Multi 800l/h
3. Sicce Multi 1300l/h
4. Sicce Multi 2500l/h
5. Tunze Stream 6000
6. Tunze Turbelle 1600/2 (12 hours a day @ night)
Any of the above pumps should be replaced?
Oh I've already checked at JBJ website, they recommend me using the 1/5hp model.