Rainbow Shark harassing Platty - What to do??

Pictus cat doesn't belong in there too. When he gets big enough he will eat anything that fits in his mouth. They also like schools and get 6". You'll have the same dilemma as you did with the shark.
 
As long as the fine-tuning process is still underway, let me suggest taking the solitary bamboo shrimp back and trading it in for a nice batch of some different sort of shrimp. Best bet would be cherries: relatively common, relatively cheap, and way easier to SEE in the tank than most others. Leave aside the fact that I feel sorry for any creature kept as the only one of its kind in the habitat. shrimp, while not schoolers in the fishy sense, do certainly interact with others of their species. With luck, these interactions will result in an increase in the shrimp population, which can be both interesting to watch and mildly lucrative in a very short time. :)

and I just recently discovered that the bamboo shrimp will get very much bigger than I previously realized. Was at PetCoWorldSmartLand the other day and saw the one they had, it was durn near 3 inches long and as big around as my thumb. This is nearing the line between "pet" and "put another one on the barbie" territory, imho. :)
 
Here's a link to a great site where you can plug in your tank size, filter size and what animals you have and it will tell you which ones are not appropriate, get too big, will eat others, need different water conditions etc. You can save all the info so when you want to add a fish you just plug in the new animal without having to go through putting in all the other stuff and it will then tell you if the new one works before you buy it, and more importantly before your kids get attached to it. http://www.aqadvisor.com/

Might save you buying a much bigger tank when the kids can't part with a fish that is suddenly too big to turn around easily. It's more common than you would think since many pet stores don't have good info on the fish they sell.
 
Must be fun trying to sort out stocking plans for two new tanks (plus cycling, etc.) all at the same time!

One more piece of advice re the bamboo/filter shrimp: They're not that easy to keep because they feed on free-floating microrganisms in the water column. From what I've read here on AC and elsewhere, it takes a pretty mature tank to support them. (They are fascinating to watch, and really striking looking, so I can see how you ended up with one. :) )
 
I have 2 cherry shrimp and I haven't seen them in a week, they hide inside a crevice in a piece of driftwood *shrug*. As for the shark that you had....yea I have a red tail shark and he is tiny....and a jerk...even my rams run away from him, which makes me laugh.
 
my favorite 10 gallon setup was with just a couple male guppies(they did fine together without any fin nipping...no females in the tank), 5 or 6 cory hastatus, and a bunch of red cherry shrimp. I had lots of java fern, fontinalis, anubias nana, and a few small crypts. It was a really cool low tech tank....I love this hobby!
 
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