I have an established 20g L. currently in it I have: 1 female twinbar platy who is pregnant 2 platy fry about 1/2 an inch survivors from a previous pregnancy. 6 danios (3 gold and 3 zebra) 5 corry (3 emerald and their two jubli friends rescued they all school together) 1 bn I had an apple mystery snail but it passed taking my two plates with it from an ammonia spike when I was away on vacation. Tank stable reading back normal now all fish healthy. so my question is. I was considering on getting another schooling fish something small like neons, or some other sort wanted something colorful that popped in a way. would this overload my tank or do you have other suggestions. I do weekly maintenance and I don't know of it will make a difference but when I am done with my betta I plan on working on replanting this tank with live instead of fake plants.