I have been keeping aquariums for... 40 years?

Initially it was all about German books. Then it became about Japanese books. Then it became about dumb shits on the Internet doing something completely gonzo and everyone else taking three years to figure out that they're desperately full of shit. Now? Now it's dweebs on Youtube fastforwarding through all the bullshit they have to go through in order to get macro shots of shrimp eggs.

Ask three aquarists for recommendations on methods and you'll get six opinions. None of them will talk about what didn't work except dismissively. All will swear by their current method to the death. Ask them next month. their opinion will have changed. You're talking about a hobby where the internet claims Discus will live fifteen years in captivity while pet stores will declare victory after six months.

I've been describing planted tanks as "pet ecosystems" since 1986. Here are a few tips and truisms that I haven't changed my mind about ever:

1) The bigger the tank the easier to take care of. Bigger tanks have more capacitance. They're less prone to shocks. Easiest tank I ever took care of was a 72 gallon. Most pain in the ass was a 7. 72 gallon I changed the water every couple months. 7 I changed twice a week.

2) "Biological" filters are largely bullshit. Their performance depends heavily on the health of their microflora, which can change in an instant.

3) "Natural" considerations are hopeless because none of the fish or plants you can buy share continents, let alone rivers. Shit, most of the plants you can buy aren't even true aquatics. Example:

- Pearl Grass (Hemianthus micranthemoides) is a North American ground cover that prefers not to be in aquariums at all. We had some in our green wall for about a year.

- Hornwort (Ceratophyllum demersum is a true aquatic spread to six continents... but naturally, it's 1-3m tall.

- Guppy Grass (Najas guadalupensis) is another North American plant that lives in ditches from Alberta to Belize.

All three of these plants are full-sun - in other words, they want about twelve times as much light as any aquarist will ever give them. In your example, a Vietnamese gourami and a bunch of Japanese shrimp spend time with a South American snail in a perfect melting pot of... not nature.

So you need to acknowledge that you're doing shit every bit as synthetic as keeping South American parrots with Japanese kudzu and weird interactions will happen. Also, what you've got coming out of the tap will govern what's going to work and what isn't. Until it doesn't.

Most successful small aquarium I've ever seen was my father-in-law's. In order to prove that his methods were better at keeping algae down than mine, he snuck a UV sterilizer into his filter. Sho'nuff, he never had to scrape his tank and his fish never got sick. I had great plants and no algae until the local water authority decided to change their phosphate injectors and poof I had green soup. The hardcore aquarists I know literally start with RODI water which has not only been stripped of everything, it takes ten gallons of water to get one gallon of RODI.

So if anything? Take it easy, don't let the purists on Youtube push you around, and consider victory to be whatever causes you more pleasure than aggravation.