Di only filter problems

I have just finished setting up my tank. I have water coming in and going through 3 filters that I took off of a 300gpd ro system which then runs through 2 Di tanks before going into my tank. It is then passed through a third Di tank. All tanks have fresh resin in and my ppm is still coming out over 20ppm...is that normal? 

Depends on beginning tds. Also, is it possible that your tds meter not working? Where and when did you buy the resin? Send photos of setup and let us know what resin you use

listening to your description I'm getting a picture of water passing through three 10inch prefilters followed by two 10inch DI canisters then into your storage tank, and then passing through a third 10 inch DI canister before hitting the glass. 

If this is the case, I'd guess that your tap TDS is quite high to start with and you need an RO as well.

The forum really needs to know your tap TDS in order to properly help you with this question.

What resin is it! Could also be faulty internals inside the DI vessel.

Thanks for the replies... Will check my tap tds and also get some photos uploaded in the morning... Thanks again.