It needs to be kept mostly frost-free. It will grow best in full sun. At this stage it will grow well in regular potting soil with normal watering, but will need a free-draining soil when it is larger. It will grow in regular slightly acid soils but not so well on alkaline soils or very acid soils.

Actually, most - not all, but most - citrus produce seeds with nucellular embryos - they're clones of the 'mother' plant. But, you'd have to grow that seedling out through its thorny, upright-growth habit juvenile years before it reached sexual maturity, lost the thorny habit(on mature growth), and began fruiting. Most commercial and hobby citrus trees are created by grafting/budding 'old budline' scions/buds onto appropriat rootstock - in most cases, trifoliate orange, Flying Dragon trifoliate(for the most dwarfing) or sour orange seedlings. Or, rooted cuttings. These resulting grafted or rooted specimens have the spreading, orchard-tree type of growth habit and absence or diminished thorniness that you would not see with a seedling.

Many, if not most, citrus produce nucellular embryos rather than zygotic, so resulting seedlings are essentially a clone of the 'mother' plant. From a friend who 'plays around' with citrus: "First of all the hybrid seed thing DOES NOT PERTAIN TO CITRUS, except for a very few varieties, Clementine being one. Almost all sweet oranges, true grapefruit, lemons, limes, pure mandarins (other than King and Clementine), most Tangelos, hybrid tangerines and tangors (except Temple) do come true from seed. If you planted a Clementine seed you will not get an exact copy of the mother tree, but will get a mandarin type of fruit." However, seedling citrus have to grow through a relatively long 'juvenile' period, during which they exhibit very thorny upright growth before they 'lose' their thorniness and begin fruiting. You might have to wait 5-10 years or more. Most commercial citrus plantings are done, as dan_staley indicated, with grafted/budded trees, using trifoliate or sour orange rootstock and 'old' budlines of desirable mature citrus cultivars. Some hobby/containerized citrus, like Meyer lemon, are routinely propagated from cuttings Seedling citrus do make handsome container plants - in spite of the thorns. Remove & clean the seeds, allow them to dry only for a day or so before planting - if they get too dry, they lose viability.

Aliel, as far as I know, Meyer's does grow true from seed..You would think the seller on Ebay could answer this question, especially since they're selling them..They should be able to answer this question..(S) Toni