So, wanting to set up a small Oase Styleline 85, which is 70 litres or 20 US gallons. It comes with an internal filter, a Bioplus Thermo with integrated heater. What are peoples thoughts on this filter? will it do the job or do I have to think about a better, possibly external canister filter. Not wanting to go that route because of the added expense, but do not want to set myself up for future issues either!