well as you can tell by the thread i am not 100% on the species i have except the blue ring I had, lol most have been smaller then 8" legs and as for the mantle size i am stil learning how to determine these things, lol as for the filtration I always have mine on systems for most of the time i have them except for the short 2 to 3 week quarintine tank time, the system i run on is over 4000 gallons with NO skimmer just pool sand filter bio tower, live rock, I use crushed coral as a buffer for the system, I run my salinity a little higher then norm as well usually around 1.026/35.5 ppt and a PH is stable at 8.6 due the crushed coral in the system, all on a recerculating water system and a healthy diet is all i usually do for them, with the recerculating system oxygen levels are very high as well and also the system generates a VERY LOW % of ammonia and nitrite/nitrate levels.
I have 1100 + tanks from 1.5 gallons to 50 gallons on my total systems with about 12,000 total gallons, fresh and marine and brackish combined. Over the years i have found almost anyone can keep a marine setup with volume as the number one key! I run skimmers on smaller stuff ofcoarse just not on my system i run the system with BASICS, just the way I prefer to run it thats all, never had problems so never changed my ways I guess, lol Just so you all know I am an African Cichlid guy thru and thru, lol but exotic oddball species are my high, lol A tank builder is my specialty though.
Hopefully i answered a few questions for you as well, lol I will post pics of my facility soon as I finish my additions and such.
Mark,