[Delphinus]

My suggestion, don't bother with the recirc mod.

I did the gate valve mod, the recirc mod, and the meshwheel mod with this skimmer. The gate valve mod is worthwhile because it makes it easier to adjust, the meshmod is worthwhile because it makes the skimmer into a TREMENDOUS performer (difference is night and day), but the recirculation mod is both a PITA and doesn't make a difference in terms of skimmate production (quantity or quality). And it's very easy to mess up, the hole locations need to be very precise otherwise you'll have a bear of a time getting the pump to attach, or you'll go through various plumbing bits trying to make it fit ... and last but not least it makes the skimmer not able to stand up on its own if you hang the pump off the side, you need to glue on a base or find some other way to stabilize the skimmer in your sump. For me the recirc mod was a disappointment. My advice is do the other two and call it a day. You won't believe how well the meshmod works, seriously, if you haven't done it already, do that one next and see if you really need to go any further, I expect you'll likely find you won't need to.