Tmc, I strongly advise you to visit the Citrus Forum where you will find many experienced growers of containerized citrus.

The earthworms have no place in container culture. They break down the solids in your potting mix, turning it into mucky stuff not suitable for plants. It's an entirely different story for earthworms when they're outside in the garden where their presence is beneficial.

I see no purpose for covering the top of the container with the growstone.

I suspect that you need to repot your tree with fresh potting mix.....something porous and fast draining. The folks in the Citrus Forum will be helpful with that.

My potting medium of choice is one of the Fafard Heavyweight mixes, which is predominantly conifer bark fines with peat, perlite, and is pH adjusted with dolomitic lime. It's an excellent product, right out of the bag.

i agree .... on repotting...

i would have done it a few weeks back ...

but what i dont know.. is if you can do it.. without aborting the fruit ...

also... think long and hard about what cures you use in soil ... if you plan on eating the fruit ...

many things to ponder.. and i would also defer to the citrus peeps ...

but one thing for sure .... WATERING IS NEVER A SCHEDULE thing ... you water when it needs water.. and most trees like the media to nearly dry before you water again ... insert finger and find out.. or learn to do it by weight of pot ...

get this.. the thing that happens.. when the media doesnt dry enough.. is you get weird bugs living in the media.... and that might be right where you are right now ... so though you think the issue is the media... the root cause.. might be your watering .... [there is almost a root pun there]

i wish you luck ...

ken

ps: now the real .. next question is... have you ever grown a tree indoors???? .... it might be a wild ride ... especially if you are up north.. in the great white north... and have a forced air furnace ... and that again.. is where watering might become a nightmare ... besides indoor humidity issues in winter .... one thing for sure.. your outdoor summer watering schedule.. will be near useless indoors .... this is where it gets real hard.. if you havent figured that out yet.. lol ....