Can a DWC be this?

[Tradewind]

No, this picture is not it, just a sump.  II think I understand that a DWC is generally accepted to be a raft system.  I want something like that, but have found that the only foam board around is insulation board with plastic, paper or foil glued to the product.  I was concerned about this extra material and the glue used to fasten it.  In an attempt to find another way I come upon an idea which I am sure is not original, however I am not sure it would be the best approach.  I have two 20"W x 26" L x 6" deep poly tubs and placed end to end pretty well run the length of my sump.  I have found that three pieces of 4" drain pipe cut in 19" lengths and set side by side fit very well in the tubs.  In total that would give me almost 10' of pipe with holes about every 4", I am thinking.  That gives me room for about 30-  2" net pots and would be more than enough for my fall crop of leafy vegetables.  It would not have a foot print as it would be directly over my sump draining back into it with an overflow in each tub.  It would be fed from the same line that feeds my grow beds that comes out of a Radial Clairifier that would be removing most of the solids.  

 

Is this a good way to go?  If not, please give me the shortcomings.  I also thought of just using more grow media and embedding the net pops in the grow media also with an overflow.  In any case which might be my best bet.  If neither seem feasible what would you recommend that I try?