Importugal, you're doing way too much to this new tree. (S)
First, there's no need to water daily, (only water when soil feels dry) Give it a hearty drink, till water seeps out of drainage holes..(the pots does have drainage holes, right? Then allow soil to dry a bit before adding more water.
Also, you're fertizling way too much. I don't know of any plant that requires feeding 2-3 times a week..What type of fertilizer are u using?
It's important to fertilize following container directions..Citrus or Azalea fertilizer works best. Everyone has their own feeding schedule, but they follow dossage on fertilizer box.
You can burn roots by overfeeding.
Next, when relocating a citrus, it's bound to lose leaves..a different environment and all..
Did the citrus need repotting? Was it rootbound? What size pot did you switch to? If a plant needs repotting, it's best going up 1-2 sizes..
I hope you used a well draining soil, especially since you were overwatering.
So, cut back on water, feeding..Make sure container isn't too large w/heavy soil. Good luck, Toni

Whoops! Thanks, Toni. I'll try your suggestions. The pot it's in now is only slightly larger than the original, and yes it does have drainage holes. Fertilizer is a standard all-plant kind but I'll try a citrus. I'm not sure what rootbound means--I'm a little new to this, obviously, and first time with a citrus!

Hi..Is your soil well-draining, Inportugal? That's important, too.
Did you happen to read instructions on the fertilizer you're using? Did it say how often was meant to feed?
Yes, try citrus ferilizer..MOst are pellet types, you spread atop soil, then water..Most last 3 months, so u don't have to worry about overfeeding. I believe most citrus fertlizers are time released..which basically means everytime you water the plant is fed. And it's so much easier than mixing..Good luck, Toni
Rootbound means roots are crowded. Sometimes so bad they're growing out of drainage holes..

Hi again, Toni. I'm still having problems with this lime tree. I've cut way down on watering and fertilizing, which helped for a while. But the tree isn't healthy, as the leaves continue to drop and are turning yellowish. The other day after watering I lifted the pot off the dish it sits in and found tiny little pink mites? in the dish. What are they??? Could they be the source of my problem? Should I take the tree out of the pot and repot in with fresh and better-draining soil? And maybe in a different pot? The pot is clay and the shape is sort of conical, about 13 inches deep. Thanks for your help!

Howdy Inportugal. Pink mites? LOL..Never heard of the pink version..
Are they only in saucer or on leaves too?
How about soil? Any found in or on top?
The best way to tell if your soil is well-draining is, while watering, water should seep into dish..if it sits, soil is too heavy.
I think pots run in even numbers so you might have a 12 or 14". You can measure diameter, across one side to other w/measuring tape.
To be honest, if it were my tree, I'd unpot the whole plant, toss out soil, use a clean pot, add fresh well-draining soil..Water thoroughly, until water seeps into saucer. Then place in bright light gradually setting in direct sun.
Is your tree outside or house? If you summer outdoors that'd be great. I see you're in z10, so your tree should do wonderful. I wish I lived in your zone..(S)
Did you find citrus fertilizer? It's difficult locating where I live, so I have to order online.
Oh I wanted to mention, there are many reasons leaves yellow..Insects, overwatering, underwatering.
Inspect the entire plant for insects..look for bumps, white cottony patches, webbing..Mites are hard to spot, at least until they build webbs. One way to check is place a white sheet of paper under plant, tap leaves. If mites are present, you'll see little specks on white paper. You may need a magnifying glass to detect them, depending on your eyesite.
Do you feel the tree was unhealthy when you purchased it? If so, can you return it?
Did you buy locally? or online?
Another way to check soil is by either using a watering guage or what I mostly do is stick finger in soil, (as deep as my finger goes) If soil feels wet I wait a few days and recheck..If dry then water.
Clay pots work well, but when new pots are used they should be soaked for an hour..otherwise clay absorbs water. Was your pot new?
I wish you luck, and if you have anymore questions ask away..or keep us posted on your progress..Toni

Hi Toni,

Thanks for your suggestions. I repotted the tree with fresh, well-draining soil, back into its original pot. While doing so, I found some wormy things living in the soil, and some tiny white stuff that could've been eggs from the wormy things. The roots seemed really unhealthy, and probably drowning in that pot which was too big. I never did find any bugs on the leaves or branches. Whatever it was was just eating the roots! They could've been living in the soil before I suppose.

Anyway, should I prune back some of the branches that have lost leaves, or just leave it alone now?

Still haven't found citrus fertilizer.

If it still doesn't fare well, maybe I will take it back, since I bought it locally where I get a lot of stuff.

I won't repot it again until it's grown bigger--and I hope it does!

Thanks again for your help!

Import, sounds like your tree was overwatered. Good thing you repotted, otherwise it'd be a goner, (if not too late already)
Maybe it's best you return and choose another tree, but if you want to play dare-devil, lol, keep the tree, water less...now that it's in well=draining soil, it might be fine..but it's like starting from scratch, since it's lost so many leaves.
I checked around for you and found several types of citrus food on Amazon.com They sell pellets/stakes/and foliar feed..but I'd steer clear of stakes..they're basically useless.
Went through Bizrate.com, after doing a search for citrus ferilizer on search engine, which took me to an Amazon site that sold citrus products..
Can't help u w/the worms..are they white or black? If black or dark, they could be milipedes. Milipedes are somewhat harmless, but I've heard tales they eventually eat roots, which isn't good.
Before I was able to find citrus fertilizer, I used Azalea food..it worked great..Let me know if you have problems locating it and I'll check back and get a direct addy..Also, let me know what you decide to do about the tree..Toni

Thanks so much for your help, Toni. I can check amazon, but first I'll check at the nursery when I go back either to change trees or get another one. People who have in-the ground trees here use sulphur?? or a sulphur product, and that's it. I'm going to wait a bit though and see how this one fares. It's still got quite a few leaves. Since I don't know what lime tree roots should look like, it's hard to tell if those were damaged beyond repair. No sign of any more worms.

Thanks again for all your good advice!
inportugal