Help have I done to much? Plenum and filter question

dcproductions03818

okay heres the deal. I have a 65 acrylic tank and a 25 gallon sump tank for a total of 90 gallons. I have a wet/dry system with a return of 1000 gph. I also have a coral life 65 protien skimmer and a Fluval 305 canister filter with no media(ie carbon, ammo chips) just filter pads. My question is this When I set up my tank I put a 1'' plenum in. In the long run is this going to be bad. everything I read says no skimmers with plenums etc.

Im keeping all my filtration but do I need to worry about the water below the plenum escaping into the tank water ans causing mass chaos.

dcproductions03818

I forgot to mention it is a mixed reef tank with


90 pounds live sand
75 pounds live rock
2 clowns,
3 damsels ,
1 cardinal fish
1 blue devil damsel
1 yellow/purple damsel
1 yasha heshe goby and his unidentified shrimp pal
2 serpent stars
2 brittle stars
1 green star polyp
2 anemones condylactis
5 blue eyed hermit
12 equal handed hermits
10 american star shells(turbo snails)
and four nassorius snails