Your tank is looking very good!!! The Gloso is spreading very well and the crypts are sweet!!!
The Tiger Barb is looking Happy! They are TOUGH FISH!!! It is good to see them when they get full grown and their adult colors are cool! At the age he is I doubt you should have any problems with aggression! The rest of your fish look very happy as well!
The DIY skimmer is a good idea, but when the water evaporates it will go out of adjustment. I would get one of the Fluval surface skimmers that is attached to your filter input. I have used them for years, and they work VERY WELL! The skimmer floats, so it will adjust for evaporation, and it pulls water from the top and middle of the tank too, so it does a good job of removing waste! They are pretty cheap to IIRC. I think the last one I got was around $12. But that has been 6 years ago, so it might have gone up like everything else!!! GRRRRRR
Anyway keep up the great work, and I really want to see the rest of the tank fill in!
p.s. Are your lights HO(high output) or Normal output? I am asking because I have a 29g that was given to me, and since you are getting great gloso growth with your light setup, I was wondering! Thanks