I have quite a bit of experience with clams. I have raised 3/4" clams to 2+ inches before they managed to flip over and die on me. I have raised large clams Derasa from 3" to 10" and squamosa 2" to 12" and croceas for over 9 years. They are not for the faint of heart.
Couple recommendations for a new clam owner. Do not get a baby maxima. It may last up to 3 months, but unless you are feeding it regularly, have nothing (I mean nothing) bothering it, good light, and excellent, stable calcium, you will lose it. Even with all that, most will not survive past 5 months in a normal set up.
A good starter is a derasa. Less light, more able to handle swings, and not as finicky. However, these will quickly outgrow your system. They will use heavy calcium as all clams do. So if you are not dosing or using a calc reactor, you probably cannot keep up on the calcium demands.
If you are headstrong on a clam (which I can fully support), get your feet wet for well over a year to year and a half. Try some sps. Let the tank mature with lots of life. Then consider a derasa or squamosa. However, the only one for that size tank is a crocea and they are not the good starters. They need tons of light. So, if you want a clam, a bigger tank is better. Handling some sps is good experience. Expect to spend a lot of money and a lot of heart, because these babies not only cost a lot, they die easily.
For instance, my squamosa (12") was great for years when I noticed a small bit of the mantle being held in. I saw my large redfoot conch (that ate my derasa) near it and immediately removed to the sump (the conch, not the clam). Within a month, the clam died. I did a dip (not easy on a huge clam), nothing else was wrong. Broke my heart.
