You've come to show off your tank and we are compelled to give advice for your long term success and joy in reef keeping, after all, this is the place to come for reef tank advice and questions. I read and researched for over a year before I started my first tank some 5 years ago. Currently build lasted 6 months before it ever saw salt water.
I'm not going to beat the too fast drum as that seems to be clear. Yes, moving too quickly is bad - patience is your and your livestock's friend.
So, can you go as quickly as you are going, maybe, but it does require the support system to do so. That is what I think we are all really getting at.
Here's my 3 month old 120 G tank with another 70 or so gallons behind the wall. Currently stocked with the following:
5 chromis (4 juvi's 1 adult)
2 scopas tangs (1 juvi 1 adult)
koran angle - juvi
dragon goby - juvi
blue sided fairy wrasse - absolutely beautiful fish! adult
3 turbo snails, a few hermits and 2 nas snales.
Plus a moderate amount of corals including a tube anem.
Is that too much too fast for a 120? Some might say yes. Here's what it looks like today:
Now, why am I able to maintain so much livestock so quickly? Several answers:
It's a big system, almost 200G in total:
-120 DT, 30 Gs in the sump and 40 Gs in the fuge
Nothing went into the tank for 5 weeks - nothing! except the sand and rock!
Of the 250lbs of rock, 50% is live rock with a few scoops of sand from 2 established tanks.
This tank cycled relatively quickly because of the live rock. You do not have live rock... yet.
I have a dedicated over the DT fuge that is bounding with bugs for the last 2 months as is the DT:
The fuge helps a lot with bio filtration! I also, have the back up equipment to make it all happen, like a very large skimmer, GFO, carbon and Calc RXs plus a controller to keep it all in sync:
What is being said is that the pace you are working at is at odds with what the tank can handle as you don't necessarily have the appropriate set up to handle that speed. Can your tank work the way it is currently, sure, but not at the pace you're throwing bio load at it. Also, put some thought and research into what goes in the tank before it actually goes in the tank. For instance, I will never put a mushroom in my tank because I know they spread like a weed and in a few years I'd have a mushroom dominated tank...
Also, that mandarin, with out real live rock and the bugs that the it eats, it can starve - unless its been trained to take prepared foods - relatively low probably of long term success that way... Sure, I've got tons of bugs now, but a mandarin isn't going in for at least 9-12 months...
There is good advice in the thread, it's up to you to sparse it. Please realize I am NOT saying success only comes if you have a reef the scale/complexity or budget that I do (clearly proven not to be the case!!), but you also have to know your tanks limitations with the current equip/setup and the experience you have.
First we crawl - then we walk - then we run!
Best of luck.