The blotches are in the leaf so it's not the spray.

If it is too much potassium how do you counter that?

I've used the Epsom salts already.

I was think it was severely lacking something not sure what or is it a disease/virus

Using this and that and just guessing is going to harm your tree more than anything and how do know that you may be over supplying one nutrient over another?

Why not use a very good fertilizer that provides all the nutrients your plants need and make sure your pH solution is acidic enough to make all the nutrients available?

From here, it's all just guessing the cause and no one exactly sure what the effect is from.

Mike

I've used a slow release complete citrus fertilizer 6 weeks ago. It's possible that there may have been an over supply but I haven't used anything to excess and it's in a pot.

The ph of the soil was 5.5 so I've raised it by .5 to 1 point. 2 or 3 weeks ago with liquid dolomite

What kind of soil did you use? How old is that soil in that pot" How long does it take between each watering? How do you know when to water?

Then, what kind of fertilizer? What brand? What numbers?

A quick release immediately available nutrient fertilizer is much better than a slow release..

Please also let us know how you're testing your soil's ph and please provide a picture of the underside of the leaf. You say your tree has yellow blotches on the leafs but you used a citrus fertilizer 6 weeks ago. Were there any symptoms before your fertilized? Did these spots develop after you fertilized/ have they worsened since you have fertilized?

Top of leaf

The slow release fertilizer is 17-2-7 NPK I've also used a 22-6-12 NPK liquid fertilizer.

The symptoms were not there 6 weeks ago as there was no new growth. It seem to be on new growth.

The soil is 6 months old max premium potting mix. The tree gets watered 2 to 3 times a week.

I got my ph kit from my local agriculture shop.

It has 2 lemons on it now which are transitioning from green to yellow.

I think it's severely lacking a trace element like zinc or manganese or both if it isn't a disease/virus

High humidity and warm weather (not hot)... looks like a fungal issue. Put it outside where it gets breeze and sun

Well I live in a hot humid place. The tree lives out the front of my house gets about 7 hours of sunlight