37g issues and stock

I returned 2 fish(from 20g) to the LFS and gave them the discus, hatchets and angel...In return for the 2 fish(albino Paradise Fish) I got 6 Rummy Nose Tetras.. I may just do a large school of these guys with my rams. May the rams feel safer and happier then having barbs. How big of a school can I do?
 
You could squeeze 15 into that tank, but overfilter like it's a goldfish tank lol
 
Well... my marineland 200 bit the bucket... it was making a loud grinding sound in the motor, had it running for 3 years, no issues. I unplugged it cause the sound was so loud. Going to put one of the filters from the 20 onto it, TEMP, till I can get another filter for my 37...since the filter been turned off, the fish are now all over the tank.. guess the sound was bugging them.
 
Eheim canister is my personal favorite :P
 
The grinding noise could be an impeller problem (sand?). It may just need to be cleaned but if that doesn't fix it, impellers are cheaper to replace than a new filter... if you liked the filter, I haven't used that 1.
 
Well, I moved it to my 20g and took the QUIETFLOW 30 and put it on my 37g... Now it stopped grinding. Well not gonna move it again so leaving it on the 20 and pick up another filter for the 37g. Maybe another 200... after I get a glass top.
 
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