Thought I would do a quick update on this thread.
Here is how the tank looks at the moment. The second background is in and repaired. I'm planning on curing the backgrounds for 2 weeks before I'll attempt putting in any fish.
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This is a pic of a 300gph pump behind one of the backgrounds.
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The pump feeds these undergravel jets.
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So I can stuff the back of the backgrounds with filter material and thus have my backgrounds function as filters