This may quite possibly be the stupidest question asked here all day, but it's baffled me.

I have a glass CO2 drop checker, the standard-issue looking ones with the bulb at the end. I cannot get the liquid into the bulb. I'm not kidding. I put the liquid into the drop checker, and it just kind of gets halfway through the bend. I move it around but the water won't flow into the bulb even though there's a clear pathway there. Could someone tell me how to do this or what law of physics I'm violating here?

There is an air bubble in the glass bubble stopping the liquid from entering.
For me, I've either used a pipit to inject the liquid, a bent coffee stirrer as an exhaust, or just slowly tip so that the water pours in leaving a space for the air to escape.

HTH

I guess my problem is once I get an air bubble I have to start all over again and dump everything out and try again I have a medicine dropper but I think a pipette would be slightly easier.

I have a flexibile pipet that goes around that little corner and puts it directly in the sphere.

Did you try and suck out the air to force the water to drop?

Where does one go about getting one of those?
I did try suck out the air and it seems to work, but when I put it into the aquarium it seemed to get an air bubble stuck in there again. I think a pipette would make this much easier though. Probably already got aquarium water in my precious 4 dKh and Brementhol Blue mixture in there.

It's also hard to get those things in without getting a bit of tank water in the big air bubble when the thing goes in. Maybe that's the point though

I got it. Stuck a bit of airline tubing in there and effectively blew the bubble out. It looks okay now. Just need to get some CO2 in the water and see how she performs.

Looks like I might've added too much brementhol blue. Fortunatly you use so little 4 dkh water it's not too expensive.

I ordered some 1 mL pipettes off eBay....25 of them I'll be up to my butt in pipettes anyway.

That sure beats pipettes up your butt, unless you're into that sort of thing.