Need a bit of help please!!!

[xfactor6699]

So I've got a 40g hex that's 24 inches high and I want to fill it about 3/4 of the way up and do a betta and some harlequin rasborias and some small corys(not sure yet) but here is my 2 problems one I'm going to use a aquaclear 70 hob and set up a piece of wood under it to catch the water but if the filter tube goes straight down it will go into the ground not the water so if I put in some elbows to go around the land into the water will that work and my second is I either want a frog or a crab I've looked at moon crabs and fire belly frog but I'm not sure any other advice please help me with this

 

[alLexX]

the crab will eat your fish

 

[xfactor6699]

the crab will eat your fish

I'm told moon crabs live mostly on land and they are mouth less and are mostly herbivores atleast that's what I could find but dont know much about them

 

[alLexX]

I'm told moon crabs live mostly on land and they are mouth less and are mostly herbivores atleast that's what I could find but dont know much about them

just cause there mostly herbivores doesnt mean there completely herbivores. and if its mainly land based,wouldnt it be kinda mean to have its only land access a peice of driftwood?

 

[xfactor6699]

That's why I said maybe

 

[xfactor6699]

Can anyone tell me if the way I want to set up my hob will work or comment on anything else lol