there are 140 sewer crystals so obviously i am not going to go into specifics to where each one is. But i will tell you that if you look on your map ( by pressing select ) the areas that are not yellow are places that you havnt been to yet meaning that there are probably sewer crystals there. Another thing that you should know is that there are some sewers in the level that you can only get to using the magnet boots. A last thing that you should know is that when you get the map-o-matic in a later level which you get for helping your army buddies in an optional challenge, you can use it to find hidden places on your map. This is really good because there are lots of hidden sewers in that area of aquatos(hidden places are shown in green on your map. But, the best thing about the map-o-matic is that it actually tells you where the sewer crystals are on your map! so you always know where they are.
hope i helped.

ther r 101sewer crystals

use the map

get da map-u-matic,bitch

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