I understand about losing interest and tanks not thriving as a result - while caring for my parents, I could only manage basic maintenance on my tanks, didn't have time to mess with planting, ferts, or the usual fussing I did with the tanks, and lost a lot of expensive and lovely plants, and a few fish, as a result.
But, I'm revamping, setting up different tanks, and getting back into the hobby again now, just to keep me occupied in a way I enjoy and to focus on a relaxing (sometimes, anyway) hobby in between all the hard real life stuff. My current tanks have been getting more maintenance and care now, and looking a lot better as a result.
I do fear that you're overstocking again, I'm sorry to say it.
It's only a five gallon, and when you take into account substrate, filter hardscape etc displacement, t's actually less than five gallons total water volume. Pygmy cories are lovely and don't have a super high bioload, but a five gallon is cramped, even for those tiny fish, and they also really need groups of 8-12, or more, to thrive, and there isn't room in that tank for that many, or for them to explore and filter feed. What kind of substrate is it? Because they really need soft sand to filter feed, and to play in.
I don't know much about killie fish, going to tag
@GaryE since he happens to be a killie expert! Handy to have species experts like him and Emeraldking for livebearers.
Cardinal tetra really need a school of conspecifics, and much more horizontal space as they're strong and active swimmers. If your parents won't let you return him to the store, is it possible to look for another hobbyist that has cardinals and would adopt him? They can live for a long time, and sentencing him to live alone in a tiny tank feels awful to me.
Trying to think of the fish's welfare, and how you can have long term success with your stocking, you know?
There are fish, and as you well know, shrimp, that will be fine in a five gallon, but having just skimmed the whole journal, while you're enthusiastic and it's a very pretty tank, you have had a tendency to overstock and not get fish in the numbers they need... Not wanting to criticise, I'm sorry, just trying to give constructive advice!
Why not look for a second hand 10 or 20 gallon? Especially if you could get a 20g long, which gives you a lot more options for aquascaping, for stocking, and is actually easier to maintain than a five gallon, since the increased water volume means you have more time to spot and fix problems before disaster strikes. Then you could keep a school of cardinals if you wanted, and they're stunning when actively schooling in a decent sized space and in a group! More options for plants, for scaping, and if you add a couple more pygmy corydoras, they'd thrive in a 10-20g. You can get them super cheap if you hunt for second hand ones.
I did. Felt bad instantly. I hope you can forgive and forget.
