Hi, I had a custom tank built by a veteran tank builder using my specs. The stand is a common DIY type I found on a reef forum using all 2x4's , 6 legs ( 3 per corner, 2 on either side in the center and 5 cross beams under the tank with 1/2" plywood top and bottom. It's over built. Anyways, 2 questions: 1) how long after the tank is filled can I assume it should be trouble free long term? ( its my first non-brand tank, and I'm lacking confidence). I won't add the salt and connect everything until I feel it's solid. 2) I my stand has 6x1/2" ceder boards covering the frame which are not straight. They are giving my eyes the idea that my tank has a slight sag in the center. The level sitting on top of all euro bracing says no....is there any other way to see if the center bottom is sagging? The tank is 60Lx 30Wx 20H , it has a safety factor of 4.2, but likely a bit more because it is euro-braced top/bottom and has a 10" center brace too.