I tried to put these to the test. I have four Ultimas with another larger model on the way. They are on various tanks and absolutely love them.
Most people who have negative feedback didn't bother to set it up properly and overdo flow rates. They do require a bit of research. Like K1 beds did at first for most of us. We respect flow in so many areas, yet, for some reason, think jamming 6k GPH through a filter with a max 2.5k GPH rating and expect it to function properly or at max potential will work. If one were to try that with a hammerhead and FX5 everyone would say the owners plan is the issue, not the filter performance. It's no different in this case.
it comes down to ones goals. I in no way am interested in ever washing a filter sock again. I travel often for work and need something my wife can do that is "push button" simple if she has to help. Sumps are sweet and I have those too but the idea of never cleaning a can again is sexy to me. On larger setups, Ultimas are stellar.
Pros:
-no filter socks..........
-will handle a ray bioload easily if designed properly.
-closed loop is Is a great filtration approach
-mechanical and biological in one package
-easy to swap to another tank with a cycled filter (insurance for upgrades)
-can be setup in a different location than the tank
-room under the stand for smaller tanks (QT, pups etc)
-backwashing with a switch is so much nicer than cleaning canisters or washing filters socks or worse, both.
Cons:
-price vs traditional or DIY approaches
-to properly do a ray tank you need two filters or one large model capable of handling targeted flow.
-large size (specifically tall) and won't fit under most stands.
-most people would not like having to refill after a backwash. Hence why I setup the automated approach on my last build.
Eddie in your case I would think you could accomplish the same either way. They are the end all IF the investment doesn't scare you off. If it's a more budget oriented project, setup a sump with filter socks and K1, kick your feet back and enjoy. If you want to maximize convenience, Ultimas are sweet. I would recommend a 4000 model for your 500 gallon with a Reeflo dart or barracuda pump. That's around $1,500 with plumbing.
My 600 has two Ultima II 2000 models and two Reeflow Dart Gold pumps. I couldn't be happier. not everyone's cup of tea but is for me. I'm not knocking sumps by any means. I still run a sump with the Ultimas so I have somewhere for heaters and probes for the Apex system.
