Hi I built two 500 gallon tanks in basement but befor I fill I was wondering do you think these are safe? I used 3/4 inch thick glass. I built a frame out of 2x4s. Then made two square frames being 4 feet wide 4 feet deep 4 feet high. The frame I made is one the top bottom and corners of where glass is sealed. Like a big cube. I put the glass together in the frame. Then I sealed it. Took plywood and covered the whole tank but cut out a square from plywood in the front to see the fish and made a opening at top with lock. Waited a week only have time to build on weekends.Then I drilled one 1 in. whole in each tank. Closer to bottom. Then took 1 in. pvc pipe and conected the two tanks. This is closer to the bottom. I am going to cover the pipe with plywood and it will be a stand for a 55 gal. Then in back drilled another whole same size added pvc pipe. sealed pvc pipes waited a week now Should I add water? The tank on the right of my wall will take in clean water from filter. The dirty water will go out to the filter from the tank on the left. Do you think I should use bigger pvc for more water to go thru faster but I dont want fish swimmin thru and I also added an extra pvc pipe with water lock. Just in case I need to drain tank in an emergency. Should I add water and cycle or do you think I should change something with it. These are the biggest tanks I ever built. I just dont want them to leak and I want them to hold without comin home finding the pieces of the tank all over and my basement flooded
Since I used to work there till I moved and I buy most supplies there for 3 years now. But I told him to hold on to them till I get a bigger tank.

