I've been at this a long time, so when parameters migrate in a new tank, I tend to correct them pretty quickly. So much so that I've started new tanks with newly mixed salt water at 1.025, temp at 78 and put the fish right in. I start with dry white sand or even epoxy coated aquarium gravel, with new filter setups, new equipment, and new plumbing. I do not use live rock, because I hate the pests they bring with them, like bristle worms and Aiptasias, and I once had a BTA come under attack from Strawberry Ball Anemones that came with the live rock. Plus, I like knowing what I put in the tank. I don't use Live Sand either, because of the crap that they contain that keeps nitrates off the charts. So after I get the water to temperature, I put in a couple fish and a nem. Everyone here should be screaming blasphemy at me right about now.
In fact, I just recently setup a tank that had a crash. Darn snails died and poisoned the tank. It's rough going from 25 trochus snails to 4 in less than a week, after having them over a year. An infection broke out from a new fighting conch snail that also died. Nitrates went off the charts and my Heteractics Magnifica started looking rough. Long story short, the tank was completely torn down, drained, then setup and ran with chlorinated tap water for two weeks, with new tap water changes every couple of days to keep up the chlorine bleach smell and flush all crap out of the pumps, filters, and pipes. All this while my nem and his accompanying mated pair of Perculas were in a hospital tank prophylactically treating for bacterial infections. My rocks, which used to be live rocks from many years ago, were also soaked in a wash-tub full of tap water for 2 weeks and then set out in the hot sun to dry (sun-bleach) for another week as well.
I then setup the tank like it was new. I put down a 1/2" layer of black gravel, because it's what I have and it had been bleaching dry in the sun for years. I put in my sun-bleached rocks, filled up with RODI water, set the salinity, turned on the pumps, set the temperature (which took a day) and put in the fish and my nem. The point here is, this was a new setup with NO TIME TO MATURE at all, like many people have commented. Tank went from empty to hosting my nem and fish within 36 hours.
The trick is adding MicroBacter 7 from Brightwell Aquatics. I swear by this stuff, absolutely top notch stuff. It
is the bacteria needed to get a tank started. What's amazing is that, as the animals poop and pee in their brand new water you worked so hard to get clean and pure with a RODI system, the bacteria from MicroBacter 7 propagate your system just as quickly as the fish can pollute it. But, keep the bio-load reasonable. I have a 65 gallon with a 18" Nem, two Perculas and an Allen's Damsel, plus a 20 gallon sump. So, my bio-load is light. But still, it's a newly setup tank with newly re-conditioned equipment, cleaned with pretty much a carpet bombing tactic as far as we aquarists are concerned, and all is well.
BTA's are nice nems, and their prices have exploded in years. I had a Rose BTA that cost 30 bucks a long time ago. He grew to 12", split and then I had two 12" RBTA's in short time. I kept him for many years, 2 household moves and 3 new tanks. I used to seed my tanks with sand from an established tank. That's old school thinking. I've used what I suggested above for several years now and I can't argue the results. It just works. Just be sure you have good lighting for your nem. I'm sure you've read about lighting, right?
