Hello Everyone,

This would be my first post on here, I am quite an amateur
when it comes to citrus trees. I've had my tree for 2 years now with some ups
and downs, many more downs as of late. The tree's leaves are turning yellow and
dropping like crazy, and I'm not quite sure why.

I recently had an aphid infestation so I repotted with very
good success, I thought this was maybe the reason but even after the repotting
the tree is still not looking well.

Soil:

3 parts Vigoro Garden Mix

2 parts Play Sand

1 part Growstone Soil Aerator

A few tablespoons of citrus fertilizer

Light:

South/West Facing Windows + Skylights

I live in Toronto, Canada so less sun now that we are moving
towards Winter. Also very rainy weather as of late.

Water:

I water every 3 - 5 days or so. I do the finger in the soil
trick to see if it is dry before watering.

(The irrigation system in the photo is not being used, water overhead with a watering can.)

Any help or advice would be greatly appreciated!

Pictures: