Yet another way to pinch some pennies is by making your own sump.  To be honest I wasn't so keen on trying until Jason at AquaC convinced me to try it.  It turned out much easier than I thought, and a lot less expensive.   The cost was that of a standard 29 gallon tank, the 4 panel inserts at $.04 per square inch, and one caulking tube of aquarium sealant.  Granted I didn't make a work of filtration art by any means, but it does work and does do what I wanted it to.

    About the only things I would change if I had to do it again would be to make the far left and far right panels the same height and smooth off the exposed sharp edges of the panels before setting them. Cautious uses of a razor blade scraped along the edges fixes the latter. The former I will have to live with.

    The Shop that provided me with the acrylic were able to make precision cuts so I had them cut the panels to exact inside width of the tank.  I used a standard tape measure at several places on both ends of the tank to get the sizes.  I also checked the squarness of the tank before measuring just to be extra safe.  The idea was to have the panels snug but not tight.  I wanted them to stay in place by themselves so I could get the sealant on them.  I didn't want to try to figure out a way to prop them for sealing.  Even with careful measurements I still had to take a belt sander to a couple of areas.  If the panels were even a hair larger I am afraid that the outcome would be a cracked tank.  They were a snug fit, but not too tight to place.

    One other thing that I did was to request that they leave the paper on the panels.  The idea was that to get the best joint I could between the acrylic and glass, I would want to rough up part of panel.  Having the paper still in place makes this so easy.  What I did was measure 1/4" in from all sides of the panels that would be touching the glass.  Then I took a razor blade and scored along the measured marks using a straight edge as a guide.

    After I had the 1/4" strips peeled away, I took some sandpaper and carefully sanded (by hand) the shine off the exposed acrylic.  I think I used 150 grit or so.  I imagine so long as one is careful any grit available should work.  The idea is just to get rid of the smooth surface and make a larger surface area for the adhesive to stick to.

    So now that the panels were snug fitted and prepared.  Next up was actually placing them.  For this I did two things to get them in position.  The first was to carefully layout the measurements then place masking tape on the outside of the tank making sure that I marked which edge of the tape to line up with.  Second thing I did was to use 2x4 scraps to get the distance from the bottom for the two panels that do not touch the bottom of the tank.

    After you have the panels in place, slap on the sealant.  You will want to have a plan of action.  Figure out which panel you will do first, second, third, etc..  You will likely still have some area that you cannot reach with the caulking gun.  For these areas I suggest using a small putty knife to get the sealant there, then use your finger to smooth the joint.   Dipping your fingers in water before forming the joint helps a lot.

    Feel free to get liberal with it.  I used almost the whole caulking tube on my little sump.  I likely over did it, but that is why I got the caulking tube so I could get plenty one there.  Expect a mess however.  Also if you are sensitive to the smell of strong vinegar then you may want to do this outside as the sealant vapors are quite strong.

    Many suggest that you use a heap of math to figure flow rates, etc..   There are a couple of reasons I did not follow what the math and others suggested.  One is that I was not sure of the flow I wanted through the sump.  Another was that if I wanted to swap to a larger pump latter I could without hesitation.  Yet one other was so that I could fit my hand down between them and under them if needed.

    Once you have all the panels placed and sealed, you will need to wait for it to fully cure before you do anything else with it.  When it is all cured you can take a razor blade and carefully trim back any of the sealant that doesn't look good, or is somewhere it shouldn't be.  Use caution with the razor around the original sealant used to build the tank.  One of the last things you want is to go to all this trouble and end up with a leaky sump.