Handy Jellies, can you help me fix this?

Sure. First drain all water above the crack, and use a bunch of caulk or any of the various epoxy resins you can find at a hardware or auto repair store. Let it cure completely before refilling the tank.

You could try to use sanitair silicon sealant.
But like @cockswain stated, drain the tank before you apply it, because it needs a dry surface.

ptfe tape

Thanks, folks. I know how to do the repair, I was kind of hoping someone had a brand name. I’ll ask my hardware store guys about epoxy resins.
@sakura : Thanks for the suggestion, but teflon tape really only works as a thread sealer. I have a couple extra rolls if anybody needs some! :-)

Some of the epoxy plumber’s putties can even be used on wet or submerged surfaces. They will cure under water.

Brand doesn’t really matter, you’ve got dozens of options that will solve the problem. But if you insist, use DAP silcone caulk (white), or J&B Weld epoxy resin.

Araldite epoxy resin or if the crack gets wider Araldite putty. Just make sure you mix the stuff well before use or it won’t cure.

Aquarium grade silicone. Drain the toilet first. Let the silicone dry and it will last indefinitely.

I can send you all you need but if it is an immediate need look for a plumbers putty type epoxy repair stick.

put a strip of Gorilla tape over it after drying the area off with a rag, that stuff will probably lst longer than the toilet XD

@XOIIO : Under water? I want to do an inside fix, as pressure, although minimal at first, will spread the crack a bit. (I’ve had to deal with this before, only at that time I replaced instead of repaired.)

@JilltheTooth on the outside of the tank is what I mean, and i will definitly work best until you do a real fix, although I’d probably just leave it.

Drain the tank, the valve is at the bottom of the intake line. Dry the tank and use a good silicone caulk on the inside.

Oops I thought it may work if you layered it over? Never mind…good luck and I hope you find a solution

If you use caulk, get the ones labeled for bathroom use. And get silicon.

I’ll come over & help you replace the toilet…If I lived closer, I really would ;)

Thanks, @SpatzieLover , it is easier with two!

All better, all fixed, no more water where it shouldn’t be, thanks all!