The more you over populate or even bring it up to the rule with say Neon Tetras, you will have more work to do cleaning and changing water. After a year or two many people will tire of this and sell the aquarium. Or let the Nitrates build for for a year or more by just adding water as it is needed, because they no longer have time or want to expend time on the aquarium.
If you keep the load down to half or less of what it might be, much less cleaning, much less changing water and people who do this seem to keep their aquariums for a long long time. Of course there are exceptions to every rule, I know of one aquarist who keeps Oscars and does a 50% water change daily. He is very successful, but he is wholly into aquariums and nothing else. And has had them more than 10 years of course some ot the Oscars have been replaced.
I prefer to sit back and just watch the fish glide around the tank swimming in and out caves, fake plants which they seem to thoroughly enjoy. The less work the better I enjoy my aquariums.
Everyone is different, but this is something a beginner needs to think about. When I started I loaded the tanks to the max and started more and more tanks. The work soon became overwhelming and was taking time from my other hobbies, so I let some of the fish die of old age and transferred all the rest into one tank and let them die down to half a tank load and the joy of being an aquarist returned. When they all died off, I cleaned the tank, got a new XP3 filter, had a good start when disaster struck when I followed the directions that came with the filter, I knew better and questioned rinsing some of the filter ingredients with tap water. But I went a head and did it and it killed off all the bacteria in the bacteria converter and I used a new brand of ammonia converting chemicals and it was disaster. Lost most of a 90
gal tank with 9 Tiger Barbs, 5 Pink Tinfoils and two Paradise fish.
I moved all the survivors to my 29
gal tank. Two tigers actually are going strong and the Paradise fish are great. I had three Tigers but two attacked the weaker one and removed its tail fins and it died. But for some reason they did not bother my 5 platies, the 4 danios but they did in my Chinese Algae Eater, (may have been the Paradise Fish) and I have since added 3 more Tigers and now they bother no one just chase each other around my 29 gallon tank which has 20 inches of fish, more than I would like in the tank, but it was the only rescue tank available and it had been running so long it accepted everything with no ammonia spike even the addition of the 3 new Tigers. I do 10
gal water changes every 2 weeks and vac the gravel.
I add water often as necessary to replace the evaporated water and I measure the water parameters daily until I see how everything will work out. The Platies are very old and so are the remaining Zebra Danios. so I expect the fish load over all to gradually go down until I just have the Tigers and the Paradise fish in this 29
gal tank
caudelfin