Yes and I'm going to start my *****ing right now
First of all... Rehome the five goldfish, I know this sounds tough but if you care about them you should rehome them. If I remember correctly one 20g will not even suffice for one goldfish... I think all of us have started somewhere and most of us started with goldfish unfortunately...
I confess, guilty as charged. Heck, I even put 5 juvenile goldfish in a 10 gallon for 1 year. We've all been fooled by lfs-stores that give the worst information and recommendations ever. I set all my goldfish free in my pond in the summer. They've grown so big that not even one would fit 10g.
Now onto the pleco-story. Some might say that a clownpleco would be good for a 20g. I don't really think so tho, I think that a 40g is the bare minimum for any pleco. If you like these kinds of fish, you might want to try otocinclus instead, the are the smallest algae eater available in the trade, but they need a heater. Corydoras pygmaeus should also bring a lot of joy in the tank for you.
If you are trying to research your stocking possibilities i'd recommend aqadvisor.com. But I can say already that the goldfish will be a big no-no. I think your current stocking level is way above 100% now, calcute it yourself using the website ^^
I'm sorry if I may have dissapointed you a bit. i just want to heed other people from the mistakes I once made. If you're still not convinced, google the effects of putting goldfish in a small container. Hope this helped
Sent per three-eyed raven..
