I myself is using this skimmer. From personal experience, this skimmer does give out microbubles.
What i do to prevent microbubbles from going back to my main tank let the water go under the baffle like what bro tunicate mentions and I also include some filter pad or active carbon in a filter bag in between the baffles.
With that I do not have any microbubbles returning to my tank.
take note: dont forget to change/clean the ilter pad or active carbon.
Any bro can help where i can get the below mentioned:
Turbo snails, Nassarius snails, Nerite snails, Red-legged Hermit Crab.
Posting here as I cant post in the pasar malam forum.
Thanks.