QT setup. 10 or a 20 is even better easier to keep water in good condition.
Cover the ends and the back with dark paper.
Use ambient room lighting only.
HOB and foam bubble filter. Treat both foam pads with BioSpira or equivalent. I leave sets of these in my sump for 30 days. Also add a bag of ceramic media to the HOB. Matrix or Biomax work great. Soak the media same as foam pads.
Small powerhead. Aim it up at the surface so that it is actively rippling the water's surface. This will greatly increase the O2 exchange.
Sand. Yep, a bit of sand will help the fish to relax.
PVC fittings are good but also consider adding a couple of plastic aquarium plants.
Mark the tank with a permanent marker at 1 gallon & 5 gallon intervals. Makes dosing meds, water changes easy.
*** actually measure the tank. Most tanks are not the size they claim. This will help with dosing meds and or copper so as to not overdose.***