As long as you have surface movement you should be good with a tank full of snails and shrimp. Even without it, though, you can make it work by Just keeping up with the maintenance and keeping surface scum build up to a minimum.
Yes, I have two no filter jars that have shrimp and snails in them. One has been running for over a year now and the shrimp have bred twice. To me the trick is regular water changes, I do 50% every 2 weeks or so. I feed pellets and slices of zucchini/cucumber. Make sure you take the veggies out after 24-48 hours or they will spoil the water quality.
ArsenalMain 
As long as you have surface movement you should be good with a tank full of snails and shrimp. Even without it, though, you can make it work by Just keeping up with the maintenance and keeping surface scum build up to a minimum.
Yes, I have two no filter jars that have shrimp and snails in them. One has been running for over a year now and the shrimp have bred twice. To me the trick is regular water changes, I do 50% every 2 weeks or so. I feed pellets and slices of zucchini/cucumber. Make sure you take the veggies out after 24-48 hours or they will spoil the water quality.
Your tank looks beautiful btw!