PM me and I can send you some picture of the stand that I built for my 75 Gal
, and all you would have to do is fit the dimensions for your tank. You would be surprised what a good structure will hold. I use a program called Sketchup to build my stands on my computer before I build them. However depending on how you want your stand to look for a 20 gal
you are more then likely going to save money buying one vice building your own. To build a stand for my 75 & 35 lumber, supplies (pant, screws, hinges for doors..ect) it cost me about $145 bucks from home depot with a 10% discount. I have seen some 20 gal
stands $40 or $50 bucks online. Trust me they will hold your tank.