I was in the same boat with the INT vs EXT and went with the INT. I believe I have my build thread badge setup correctly? If not let me know. I'm waiting on some TBS live rock to come in, in about a week and a half. Once that's in I'll feel more comfortable putting stuff in the tank since I won't disturb anything too much after that. I plan to make the structure of that rock, more of a taller reef like mound/archway, but will have to play around with it.hey - sorry for late reply.
The Anthias didn't make it. All of them seemed to want to jump out of the tank (I had a lid, but that maybe caused even more problems). They were fun fish while they lasted i guess.
Tang wise - I have a Juvenile tang (got it as a baby, 9 months ago). So far, a 4' 100 gallon if very adequate. That being said, i just spent a few weeks in Hawaii snorkling and saw some very large Yellow Tangs, so if mine becomes that size, we'll either be getting a new tank or I will need to re-home for its own sake. That is a decision for a few years though.
Light wise, Ecotechs are great, although apps sort of sucks though. I got the deal of a lifetime on a new set on facebook marketplace.
Flow wise, I use a pair of Maxspect XF330 Gyres. I actually bought a second pair, and just clean them/swap them out every 3 months. The Gyres (without Controller), were about 100 bucks a pop and integrated right with my Hydros setup. They create as much or as little water movement as you want and are very silent. They do probably need to be maintained more than other types of devices.
In terms of INT vs EXT, the EXT will certainly hold more water. When i measure total volume in the tank + sump, displaced by Sand, Rocks and devices, I only have 86 gallons of water. I understand and EXT will give you considerable more volme and some space in the back. Location wise though, I could not swing an EXT.
Let me know if you get a build thread setup!
I tested my parameters recently and everything seems to be fine since I used live rock from my LFS but still am hesitant in the event I still need to cycle. For lights, I was looking at Ecotech Radions, Kessil AP9X, or the AI hydras. Just not sure what I should go with since I want to keep softies and LPS mainly. I would try SPS, but only way down the line.
With flow, I have a small 50g rated fluval powerhead. It's not much, but between that and the return flow, I don't think its bad for softies. My main concern is I used Bahamas oolite sized sand, along with the aragonite sand, unsure what size that was, and didn't rinse. Because of the small size, and it being cloudy. I was concerned that powerheads would kick it up too much and coat the corals. I planned to keep sand sifters which is why I decided with that originally, but am not so sure it was the right move thinking back on it.