Speakerman, I wish you the best but......
I have had my 37 gal setup twice as long as you, doing EVERYTHING right, aragonite LS and RO/DI water, and good powerheads, ect., ect., and I will not add fish yet......I want to get a pair of clowns just like you, I saw a pair of black perculas, the sickest clowns ever IMHO, and I just had to have them, so I paid the LFS 2/3 of their value, 40$, and I am letting my tank really finish cycleing before I add them. I was tempted to, but better judgement took over and I am going to wait so I can enjoy my 60$ fish and not worry about them dying!
I understand you params are "acceptable" now, but your bacterial base cannot withstand you adding not ONE but TWO fish, You just added a ton of LR to your tank and seeded or not, you stll have a dead sand bed.
NO3 @ 20ppm is still WAY to high, you need to get that down to atleast 5 before you add fish, otherwise you will have one heck of a time doing so afterwards..........If you cant get your water under control without fish in it, how do you expect to do so afterwards?!?!?
You stand a great chance of killing these fish unless you have over 20 gal of SW on hand for PWC's as your tank spikes after you add the fish. Your tank is 37 gal, 15% is like 6 gallons, so you will need a lot of GOOD RO/DI water on hand that you know is the right salinity(do not rely on a hydrometer)........
Please wait a couple more weeks, there will be more clowns I promise, if not then put a down payment on them if your LFS will allow you.
And FWIW, buying fish that just came in the night before is not a wise move, even if you have a well established aquarium. Disease will start to show in a few days should the fish be sick...that way you dont take home a dying or infected fish with something you do not want in you tank i.e. Ich.....
