redtitan23, The yellowing may simply be natural aging of the old leaves. I would however take a close look at the plant and see if it has any scale insects. I can't tell from the pictures you've posted, but in image 850 I think I can see a large scale insect (the tan oval near the leaf stem) and a small one on the lower left leaf which is partially visible. If you have one scale insect, you probably have many. If you see sticky clear drips of what initially looks like water drops on leaves, this is another sign of scale insects. If you have scale insects, you can reduce their numbers simply by rubbing them out with your finger, but that is a less than entirely effective method of control since they are often under leaves and on young branches. Meyermike has many postings that tell people what to do about them. I use two applications two weeks apart of a horticultural oil spray in the fall before I move the plants inside, and this year have not seen any scale or other typical pests on my plants.

Better, but I'm not a fan of anything MG; if you read the label carefully, you might see it falls short in CA, MG. Many here like Foliage Pro; but I am not a container grower. My mature producing Meyers in the field get 3 pounds per year of 18-6-12 with 2% each MG and CA, plus 1% each Iron and zinc... it is specially made for me; so unless you need 10,000 pounds or more per year, you proly have to look for something close to that. FYI, I have found it nearly impossible to over feed a Meyer; but mine are all inground. Do a search here for Patty (hoosierquilt) or Mike (Meyer_mike) and you will get better advice for containers.

Well, if you've read through this forum, you'll nearly all the successful container citrus folks use their own potting mix, as the stuff that comes out of a bag is just much too dense. Moisture meters like you have stuck in your pot can be notoriously inaccurate, and certainly will not tell you what's going on at the bottom of your pot, which can very well be a swamp, while the top of your soil can appear very dry. So, the first thing I would do is re-pot with either "Gritty Mix" or "511 Mix", both formulas can be found on this forum. Secondly, those same container growers prefer to use Dyna Gro Foliage Pro, mainly because it has the proper NPK ratio (it's not just about the N), plus all the micronutrients. Plus, the nitrogen is non-urea based, which is very important to prevent biuret build-up and leaf burn. You can use Foliage Pro either 1/2 strength or full strength with every watering. I would water, first, to moisten the roots, then fertilize. Never apply fertilizer to dry roots. Misting. Again. The myth that will not die. Citrus do not need high humidity. If this were so, they'd never survive in our S. California deserts, where there are still thousands of acres of commercial citrus groves. I have no idea where this myth got started. Yes, you citrus will always benefit from a hosing off, to remove house dust and discourage pests (all house plants will benefit from a hosing off), but you do not need to waste your time misting. And, I would leave your lights on longer. Meyer lemons are rather sensitive to light changes, so you'll see leaf drop, but, your tree looks to me like it's suffering more from compacted soil and lack of fertilizer, than lack of light. So, try fixing those two things, first. Fungus gnats can pop up in any soil, organic or not. They proliferate from too wet soils (which is my suspicion going on with your tree), so re-pot with better potting mix, and if they come back, you can use a product called, Gnatrol. It takes a couple of applications, but it is very effective. Another one of our forum members suggested another very effective product, just can't remember it off the top of my head. Hopefully, they'll post their product for you. Patty S.

So my tree is in ground and there may have been a general fertilizer working as well. I think I put a couple tbsp of epsom in a gallon of water and dumped it under the drip line. My tree looked exactly like this and after application the classic V pattern from leaf tip on older leaves went away. A magnesium deficiency only shows on older leaves. Manganese will show on new leaves for instance. Magnesium deficiency is more likely to show up in seedy varieties. I believe Meyer's are notorious for showing deficiencies.