Is This Okay For A 75 Gallon FOWLR With A 29 Gallon Sump?

Be warned that lionfish will eat whatever they can fit into their mouth, which will probably be your clowns at some point. I don't know how long you have had them together, and the lion may be just a genuinely peaceful one, however I would watch that closely as he gets larger. Even a dwarf can open its mouth far wider then you would expect and will eat whatever it can get a hold of. Honestly I wouldn't add the regal tang, it would do fine with your stocking list, however the issue is the size of the tank. I had two in a 125 gallon and at adulthood they swam robotically in front of the glass. It wasn't natural swimming behavior and was truly sad to behold. In the ocean regal tangs swim in schools of 500+ and they swim miles every day. Removing them from this environment and placing them into an aquarium is extremely stressful and one of the main reasons they contract ich. Another reason they contract it so easily is that their immune system does nothing to fight it off. By swimming miles every day they are never exposed to large enough numbers of the disease to kill them, however in an aquarium they have no where to swim too. It isn't a good situation at all and one of the main reasons I don't recommend regal tangs be kept in aquariums at all. They just don't do well, much like the moorish idol. It is possible, however if it does contract ich and you don't quarantine, your losses will far outweigh the gains of that one fish. Also the trigger can get quite large and might show aggression in that scenario. Triggers are not good fish to keep with inverts either as they will nip at them and kill them. You have a few different options here. You could go community FOWLR with clowns, the blenny, and other social, peaceful fish, or you could opt to go aggressive with the dwarf lion, maybe a snowflake eel if you want one, an angelfish, etc. You want to be sure to get fish which are invert safe if you want a cleanup crew, and by opting for a community tank this is much easier as most all community fish are invert and coral safe. You could also opt to go full reef if you wanted, although this would be far more expensive in that your lighting would need to be improved greatly and supplements would most likely need to be introduced. As far as cleanup crews go, personally I use almost everything. Snails; Turbo, astrea, cerith, nerite, and nassarius. Hermits; Scarlet, white leg, and mexican. Starfish; I use only the sand sifter, mainly because brittles and serpents are opportunistic eaters and will (at large sizes) kill and eat fish and other inverts. Shrimp; I keep at least 1 cleaner shrimp around (either a regular cleaner or a fire shrimp), and a few peppermints (example would be in a 29 gallon around 3 would do, of course as you get larger you'll want more. They are good at eating apstasia and work usually at night). I also have randalls pistol shrimp in a few of my tanks, but they are paired with watchman gobies. They do a very good job at stirring the sand bed however as they are always digging making their tunnel system larger. I also keep cleaner clams in my refugiums to help reduce nitrates along with macroalgae, primarily Cheato, and I keep shaving brush plants in there as well. I also always seed my refugiums with a couple of bottles of pods as they provide great food sources for fish, and really help a new fish who is stressed get his food. I have and still do use lettuce nudibranches as they are not poisonous and do a tremendous job of eating algae. Urchins will do this also and may look cooler to you, although the lawnmower blenny will do a large chunk of the algae eating on his own.

Truly Best of Luck

Tangs should have a 6' tank, especially big guys like a Regal.

The lionfish or the trigger will kill the clowns and the blenny. Maybe not today, maybe not tomorrow, but some day.

Lionfish and Tangs are opposites, feeding-wise, and this may cause issues.

You are having the problem a lot of us have when we upgrade tank sizes: When you upgrade to a bigger tank, you can upgrade to bigger fish, and the smaller fish you already have are likely to be bullied/eaten.

The trigger would not be a good addition as they get far too large. The tang should be ok, but for a cleanup crew i would add a few mexican turbo snails.

that is been particularly a collectively as because I had a salt tank, yet would introduce them one by one to verify how each and each does, then at approximately 2-3 week intervals, upload the others. in simple terms shop a powerful eye on the ammonia and nitrite tiers. you are able to upload bio-bags or maybe fritzyme to help out. known rule of thumb (or a minimum of it was once) became 5 inches of fish in step with gallon of water (such as the filtration tank. lower back - has been some years, and unsure what advancements they have made in marine filtration, yet a powerful fish keep that makes a speciality of salt water aquaria ought to be waiting to furnish you the perfect information. do no longer count on your community puppy keep as they often don't have the certainty required for maintenance in this high priced activity. I had stars in my reef tank and had no issues in any respect. did no longer have any authentic particular lights, yet they should make a bulb to in good condition your furniture if required. good success