3-4 weeks in, time for more shopping. Buy another pound of honey. Buy
this carboy kit; this will be your secondary fermenter. Buy
potassium metabisulfite AND
potassium sorbate; both are needed to stabilize (stop the fermentation). Also buy
this auto-siphon to transfer the mead to the secondary (boil some water and dip the end of the tubing in to soften it, then gently push it about 1/2" onto the top end of the siphon's plunger.
When you're certain that it's done fermenting, add 0.5g of potassium metabisulfite and 0.4g of potassium sorbate. Stir these in.
Wait 24 hours, it's time to backsweeten. 1 pound of honey adds 35 gravity points or 0.035 to 1 gallon of liquid, bringing 1.000 to 1.035. 1.035 or higher will be sweet, 1.020-1.034 is semi-sweet. 1.010-1.019 is off-dry. 0.990-1.009 is dry. I recommend the full pound, as everyone likes sweet mead.
Sanitize the carboy you're going to use for the secondary, and add the preferred amount of honey to the carboy. Use the auto-siphon to transfer the liquid from the primary to the secondary. Place the fat tube in the primary fermenter, keeping the tip above the sediment ("lees") at the bottom of the primary fermenter, and put the end of the flexible tubing in the secondary carboy. Slowly pull the piston upward in the big tube to pull liquid in, then slowly push down to pump it through the tubing.
Since your primary fermenter is 1.5 gallons, you have some extra volume, so don't worry about losing a bit of mead to avoid sucking lees into the secondary, which has a max volume of 1.1 gallons if you stop filling it about 1" below the lid.
If you want some tannic value (astringency, barrel taste) like a real wine, break 1/3 off one of these
American oak spirals, tie a piece of fishing line to the very end, and let it sit in StarSan for a minute, then drop it in the carboy. This will need at least a month to extract the tannins, but sometimes 2 months. Taste a little bit once a week until it's oaked to your satisfaction.
Once it's oaked enough, it's time for acid balance. Acid will make all the difference for brightness of flavor. Since it's your first batch, just buy some
acid blend, which is a mix of citric, malic, and tartaric acids. I'd add 0.5g at a time and let it dissolve for 24 hours, then taste. If it isn't bright/acidic enough, add another 0.5g and taste after another 24 hours.
Once the flavor is where you like it, now is the time to be patient. Don't make the usual rookie mistake of bottling when it's still cloudy. Give it a month or two to just sit undisturbed until you can clearly read large letters through the liquid, then rack like before from above the sediment into bottles. A
bottling wand will make this much easier, as it only comes out the end when you insert it into a bottle and press it on the bottom of the bottle. Use whatever bottles you prefer, but I recommend using well-cleaned used wine bottles to save money, and just buy a cheap corker and a bag of synthetic corks (because a lot of natural cork these days is tainted by TCA that can cause cork taint), as corks will allow the micro-oxygenation that allows flavor to improve and mellow as the bottle ages.