Does the ultramax incorporate the heater like oase biomaster?
Nope, I have gone for a external hydor - which has worked well so far. The trade off of a silent powerful filter seemed worth it.
TBH I really don't know what the hype is about Oase Biomaster or why it seems to be seen as the 'gold standard'.
I think there is a spreadsheet that was shared on the forum about the different filters and their capabilities which may be helpful. I will take a look later, however, if anyone reading this has it to hand....