@rina_Ontario, Sans2015, tlbean2004 Thank you all for the insightful comments. 1) Yes we are spraying our ficus tree leaves with water around 3 times a week; 2) it's plotted in a medium sized container with drainage holes (we re-potted it from a small sized container a few days ago and added clayite as an additional drainage); 3) the fertilisation is out of the question now after all the comments. So all in all, how frequently are we supposed to water it, spray its leaves with water and fertilise it ? What is your opinion on the location of the ficus tree? NB: A bunch of yellow leaves has already fallen off before. And one more is on the go. We're seriously worried. Thank you so much!

Oh it Wasn't aimed at you ohiofem!! Thank you for the compliments! I seem to be the only one in my family that finds humor in that most of them are named after the Resivoir Dogs - I just named them so it would be easier to keep track.When they were in their cells I could keep of whose true leaves were doing what, but with 15 babies and a "teen", it seems like an endless merrigoround to make sure everyone gets light and I forget!

Thank you for all the comments, very appreciated. This wasn't a bought tree, we actually germinated the seed, that's the main reason why it was indoors, also, because we live in a very heated city (surpassing 120F during summer) and it's also very dry, just a small hand full of plants can actually survive full sunlight here, Since it was so small we were afraid the sun and heat would kill it so we thought of keeping it indoors until summer ended. Lately the temperature's been nice (around 95F max) so I guess it's time to finally take it outside :) Thank you for your advice! To those who asked me about recently moving it, the sapling has always been next to a window but since it has grown a lot during the past weeks I guess now it need more sun power, hehe.

Please post a picture so that we can better tell what is going on. Also, what type of soil mix is it in? I doubt that one drop of undiluted fertilizer will have hurt the tree. Leaf drop of citrus is most often due to root rot and/or cold soil temp and some plants (perhaps not citrus) drop leaves when they are moved to a different location with a different amount of light and/or heat.