Maybe they need sun to ripen fruit? Are citrus monoecious or dioecious?

I have no idea. Many folks grow these Citrus indoors here under lights. I just do not know why I get blooms but no fruit.

Read this: http://homeguides.sfgate.com/key-lime-tree-pollination-60746.html

Interesting Vladimir. You always provide the most informative links...Thanks!

Right so theyre monoecious but indoors they need us to pollinate. Just like my pelargonium that I crossed and got seeds. Cool.

Limeinqueens, I think you mean "parthenecarpic". Key limes are not and so require pollination; some other limes are. See this: http://info.gardenguides.com/info_8512902_lime-tree-need-pollinated.html

Fruit drop may be due to root rot, insufficient sun or insufficient potassium.

Also isn't it pretty normal for young trees to keep dropping blossoms?

I have small key lime bushy trees - bushy, but no more than 18" tall at best. They do NOT drop any limes. The flowers all pretty much become limes...there must be another issue.

Can you post pics?

My tahiian lime tree has lots of flowers but never any fruitt, i dont see any pollen, should i be able to see it?

My limes are my most prolific Citrus crop, they get covered with limes..., just about no comparison to other Citrus, I LOVE them most of all. All my Citrus overwinter in a chilly but frost free garage and are seasoned outside from April 1- November 1st. Not sure if it's the bees, but they certainly are attracted to the blooms.