Depending on the location of the crack i would use something like Q-Bond Ultra Strong Adhesive it creates a super strong fix, I haven't used this for this specific application but i do know its some strong stuff.
Recently Got back into fish keeping and boy do i have a serious case of MTS going on. I currently have 7+ tanks with multiple breeding projects on the go in my bedroom of all places :P.
120 gallon housing
Geophagus Read Head Tapajos
Pterophyllum Gold
Pomacea bridgesii yellow
70 Gallon Housing
Astronotus ocellatus Albino
Amatitlania nigrofasciata Fry 1.5"-2"
20 Gallon tall Housing
Amatitlania nigrofasciata Male & Female
10 Gallon Housing
Danio rerio
Trigonostigma heteromorpha
Caridina Crystal Reds
Neocaridina Pumpkin
Planorbidae Red
10 Gallon Housing
Poecilia reticulata Males
Amatitlania nigrofasciata Fry 3 week
Planorbidae Brown & Lepord
10 Gallon Housing
Poecilia reticulata Females
Neocaridina Cherry
Xiphophorus maculatus
6 Gallon Housing
Paracheirodon innesi Trio
Breeder Box Housing
Danio rerio Fry
If you would like to join along for my adventures follow me aquariumnut on instagram
I would love to make some friends in the hobby in the Airdrie/Calgary area