100% you come across as a butthead
none of us like arguing or telling people they cant have certain fish but we have to for a few reasons really -
1. so that the original poster has a chance to learn why and stock their tanks accordingly but also reason - the advice most people give is based on experiences and mistakes they have learned. To avoid you doing the same - you have some of the most common fish in the hobby and the most common fish that are put in smaller tanks than they should be. This is perhaps the most irritating part of dealing with you - your problem whether you see it or not has been played out hundreds of times on this forum alone!
2 - this forum is read by a lot of people and it only takes a few things to slide and all of a sudden there are dozens of posts where seemingly healthy big fish are seemingly happy in small tanks (for them at least) And this is the problem you have only seen a few weeks of a young fish not the a fish in its prime at around 2 year or more when its done most of the growing and you then start to learn how much they eat how they need the water how much space they need.
A lot of fish live to surprising ages - Synodontis catfish can make 25 years! With some older! Cories can live to their teens, some tetras can live to about 7 or 8 and some cichlids should make 10 - 15.
3. Teach people alternative - there are always alternatives - always, always, always... in this case, how about ghost catfish instead of your BGK - your Pleco - lets not get started there are hundreds of alternatives - silver sharks, a little harder but how about Scizzor Tail Rasbora? Or if you just want the shark look how about a red tail shark? Clown Loaches, tons and tons of Botia Species that are more suitable.
All your doing here is, if I am honest in your arrogance to others, is making all the mistakes dozens of other have made before you.
So two options for you and both is fine by me - option 1 - listen, take advice, realise what is going to happen. Or just post pictures for people to say how cool your tank is and tell people not to comment - maybe put something in your signature? The second option will end up with dead fish but you seem be happy that you know what your doing so best to just leave you to it
One last thing though (I cant help it) - your Balas they ARE going to grow huge, they ARE migratory swarming fish in the wild, they DO NEED a huge tank - and I really mean a huge tank. BUT they are a commonly traded fish unfortunately so as big as possible is often their best option. The saving grace with your other fish is that they are slow growing to max size - The pleco and the sharks are going to cause you problems first.
And absolute last comment - your fish do look healthy right now and the fish that are suitable to this kind of tank are in great shape
And like I say its upto you if you take the advice but just do me two favors - 1 avoid advising others with your risky ideas and 2 warn people you dont want help when you post a topic.
Wills