Sealant for protein skimmer?

I have a SeaClone 150 and I was wondering what I can use as a sealant at the bottom. It leaks a little bit. The owner before me used teflon tape. What can I use so I don't flood my room and drain my tank?

 

Silicon should do the trick.

 

What kind?

 

x2, just make sure you let it dry completely before putting back into sump. check lowes or home stupid and see if they have a faster drying clear silicone in a tube.. probly run you $6-7 bucks but can cure in a couple hrs and not a whole day..:

 

goto the chalking/painting section of store. you want pure silicone or something that similiar in Clear.