Pond Boss Forums POND CONSTRUCTION Creating habitat Substrate for lined pond

I'd like to gather opinions on the following subject. I'm attempting to create a small lined pond to raise bluegill. I have other unlined ponds but my soil type allows for significant leakage so I'm trying a liner on this one. Anyway, the question is concerning ammonia buildup. If there are no pond soils on the bottom, then I'm assuming that I will lack nitrifying bacteria. Is there an affordable substrate or structure that can be placed on the pond bottom that will allow adequate surface area for colonization of such bacteria? I'd like something that doesn't decompose. What about plastic laundry baskets? The pond will have about 80,000 gallons of water and will have a maximum of 150 lbs. of fish in it. Some of the artificial structures advertised in aquaculture magazines seem really expensive for what they do.