via aqua pump help

hey guys i bought a ViaAqua VA80PF submersible pump/filter for my new lil tank and i stupidly didnt check my parts before i started modifying the outlet line (read cutting it up into itty bitty pieces ) when i wanted to attach the line to the pump there apeared to be a part missing as i couldnt attach it, i been trying to use marine silicone to attach it to the pump and to block the large end so that the water goes out throught the line but have found that if i completely seal the join with silicone then the pump doesnt pull water. so now i'm trying to seal most of it and leave abit of a gap. i hope this makes sense lol

i doubt the shop will take it back now and in anyway i really like the pump itself its quiet and relatively small so it doesnt take up much room out of my already limited space. i'm hoping to add some marshy plants and somehow attach it to my mountain and allow the water from the filter to somehow trickle through that and then into the waterfall i've built. anyway any ideas on what else to use to seal it? mabe that white tape plumbers put around the thread of pipes before they attach them.

 

take some pics then we can have a look, or try pvc weld with some other plastic pieces and glue that hole shut

F

 

Take a picture then I can help, I have a knack of fixing stuff (that I mostly break) lol!

 

pics will have to wait cos i forgot my camera at home last weekend. i dont know if i should just try siliconing the air line directly to the pump and see if that works. @Fonkie if i glue the hole shut and completely seal it so that the only outlet is the air line then the pump doesnt take up water and runs dry, hence the reason i had to cut apart my beautifully and carefully sealed seam.
@larch im usually pretty good with this sort of thing as well, my dads a boer and as they say a boer maak a plan hehe, but this has me stumped. i dont know if maybe using super glue first so it dries properly aligned and then seal with marine silicone but then if its a stuff up im in trouble. the piece im trying to silicone to the pump is like a T piece with the bottom of the T being where the airline attaches i.e. smaller. the other two are both the same diameter as the fitting on the pump and cant be removed..... hmmm i dont think. ha this is what happens when your blond i think i fixed it lol.