I have had my Chi for about a year now and can maybe shed some light on this.
I have about 4 shrimp in the tank now and did have more, but with the open top I did find my shrimp would leave and I found one who died underneath the couch. Since then I've added a lid and have had no problems. Consider it a warning as I've also had fish leave through the open top and have this is not uncommon. Yes- I do change water regularly and get it checked to ensure the quality is good.
I am looking into replacing the filter to provide a better environment for the fish and like your setup there.
I've had a few jumpers as well and only recently discovered a cover was made for it by Fluval, but decided not to go with it because it would not allow room for the light and inflow/outflow. I'm considering having some acrylic cut for it. I have definitely not had any shrimp climb out though...I find that a little odd.
I'll keep you updated on the performance of the filter and light on this tank. The ZooMed 501 so far seems excellent, although my version didnt come with the hook to hang it on the side of the tank like I have seen in some others' setups. I found mine in the terrarium section though, so that may be why.
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