I used uncured live rocks and arag-alive sand (which I think is critical), water change every other day; coral plus fish after 2 weeks. Very risky move [emoji16]
If you are using new live rocks, ammonia tends to be very high due to the die offs of sponges, algae and other organism. You can perform weekly water change and once the nitrogen cycle is stablished the ammonia and nitrite should be zero.
I mixed Seachem Calcium (Kalkwasser also can) very concentrated. Use a small syringe to inject directly onto the Aiptasia. I did this to get rid of those grown in between Zoas polyps; Zoas unharmed while the Aiptasia never come back.