Sageretia Theezans Leaf color, Chlorosis?

[clinville]

Hello all,

I bought this beautiful Chinese Sweet Plum a few months ago from my local gardening store, it was very healthy when I bought it. I live in Salt Lake City, so this tree is inside under the grow light for the winter.

I basically slip potted the tree into a larger bonsai container so that it looked nicer on my indoor grow table. It was a minimally invasive repot, and that affected maybe 5-10% of the roots. I did this about a month and a half ago.

The issue I'm seeing right now has to do with the newer leaves being very pale with darker green veins, which sounds similar to symptoms of chlorosis. Maybe there is an issue with my water ph, or lack of iron in my fertilizer? The tree still seems generally healthy, producing new shoots often, but it has dropped a lot of its previous dark green foliage. I feel like its on a slow decline but the issue can be reversed with proper action. Does anyone have any thoughts? See pictures... Thanks!

 

[DaveNuts]

They just look like new growth to me. Should get darker green as those leaves harden off

 

[Shibui]

Yellowing NEW leaves is a sign on deficiency in one of the non mobile elements ie the plant can't take it from older leaves to new growth. Iron is the usual suspect. Alkaline conditions make it even worse.
The quickest treatment is Iron chelates which provides iron but also acidifies the soil to help make Fe more available.
In most places municipal water is treated to be slightly alkaline to prevent corrosion of pipes and fittings and to reduce the incidence of heavy metal poisoning. In some places the water is alkaline just because of the local geology. In the longer term an acidifying fertiliser might be useful for your trees.

Many tropicals grown as bonsai have a habit of dropping older leaves whenever they are moved to a new location or when conditions change so losing older leaves is not unusual.