Posted: 25/03/2014 at 19:43
We don't appear to have any photos Grace - to upload a picture from your pc you click on the green tree icon on the toolbar above where you type your post and follow the instructions.
My immediate thoughts are that 4 hours of direct sunlight are not enough for a citrus, even with supplemental lighting - I would have thought it would need a heated greenhouse, or a conservatory at the very minimum.
You say you bought the plant two weeks ago - how often have you watered it? In poor light conditions the plant is hardly going to be photosynthesising at all and doesn't need much water to maintain itself. I would let the top couple of inches of soil get quite dry before watering again.
Also, is your piped water hard or soft? Citrus need soft water so they are best watered and misted with rainwater.
Looking forward to seeing the photos.