A lot of that genetics stuff has to do with which genes will be dominant or whether incomplete dominance will be the case.

A little elbow grease and a paper towel will usually clean a tank, So will a soap-less, plastic pot scrubber. Use paper towel and baking soda on a tank top. Gravel vacuum the gravel. For plants, I too have had to hand pick algae. (Sigh)

Plastic plants can be bleached. 1 part bleach to 10 or 20 parts water. That will clean them (in a bucket, outside in a shaded area) of everything. BUT make sure that they have been properly rinsed and then dechlorinated. Improperly dechlorinated stuff will leave a lethal wave of bleach in an aquarium otherwise!

Sorry about the losses. But you seem to be catching on to this care stuff. Congratulations on all the survivors!

Keep one of your new tanks for quarantine, hospital use. It is sooooo easy for me to spend other people's money. ;)