I just replaced my RO filters and now my tank is empty and not filling. I detached the supply line to the tank and NO water came out aside from an initial spray so I'm not sure what the issue is. The pressure in the tank is around 7psi. I'm not sure what the canister on the right is, I'm guessing it's for extra water storage. First pic is before I did anything and the others are after I changed the filters.
I can only think of two things to check and the first I hate to even ask. 1) did you forget to open the valve at the top of the tank? 2) Check to make sure none of the tubing became crimped or pinched anywhere. Unless you removed more connections than needed, system flow should not have changed but here is diagram of system (you may have one more filter in line with the charcoal filter) http://www.waterfiltersonline.com/installation-diagram-4-5-stg.asp