Goldfish with white bumps on tail

I dont know how I will be able to do those water changes (I've had a back injury that really limits me) and I cant afford a weekly service : ( Maybe I can do 15% 2x/week. What if I add live plants and gravel cleaner?

There are wooden wedges between the glass bottom on desk and the file cabinet - oh my - taking the drawers out will be difficult but I see what you're saying... I'll have to look
 
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