There are a few more seals in my Biomaster 350 than my other canister filters but these are inside the filter itself so I don’t see how air could get in this way.
I wasn't just talking about O-rings but, complication in general. Just look at the flow path, all of the levers, the priming system, the pre-filter system, the heater compartment, the tray design, etc. The whole things is an over complicated mess imo with many failure points in general and many more then other options. Also, if you read our last two posts you will see that we have been also thinking it may be an internal design flaw unrelated to seal/O-ring issues. The bottom line is they purge air all the time when others don't.
As far as I’m aware the Thermo 350 doesn’t have any more O rings than my non thermo model? There is an O ringed sealed cap where the heater goes. Perhaps I’m wrong but I thought you just took the cap off and installed the heater with its own O ring?
Again, complication in general. That said, a heater expands and contracts with every cycle which will definitely increase chances of leakage, even when a flexible O-ring is used, and even having the passage in the first place adds an extra incursion point.
I bought spare seals for mine, the main gasket and pre filter gasket. I need to get the two for the inlet/outlet connection unit. Apart from any other hose connections that any filter will require I can’t see where air can get sucked in unless it’s going directly into the main inlet pipe (operator error) ?
Yep, it's possible as we hypothesized earlier, that it is an engineering flaw with the design itself, that let's air accumulate, where it doesn't with other designs. Either way, the result is an annoying pain in the butt that many have struggled to remedy.
Thinking about this further my Tetratec and Sera canister filters both have the same number of potential places to leak water or suck in air as the Biomaster. I had a water leak on the inlet manifold of my Tetratec a while back that required a whole new unit.
The take away is that the Oase has a problem that other options don't struggle with. That is why I don't think they are worth the trouble personally. At least until they refine the design and I stop hearing about constant issues.
The simplest is my Eheim Classic and that only has the main gasket, an O ring inside the head unit and one on the inlet pipe.
Yep, a great design imo and just like the ADA and Fzone stainless options I mentioned earlier. They take a bit more time to clean but, the advantage is the "KISS" design with very little in the way of points of failure.
Personally, I think the perfect Canister might be a two tube combo if you will. Think 2 of the ADA/Fzone stainless ones, one small and one large, welded together and plumbed in sequence. The small one is a simple prefilter with an easy to remove lid and coarse foam throughout and the big one is regular sized with just finer filter foam, filter floss/polishing pad, and biomedia. That way you just clean the easy to open pre-filter canister most of the time and do a thorough cleaning of the main canister less often just like the Biomaster. I may grab the tig welder and make a prototype of this design in the future...
