Well, I finally discovered my mistake in building with lumber and liner in Florida. Termites have caused some of my grow beds to begin leaking. Time to make a change. We will replace the middle leaking grow bed with two rubbermaid stock tanks of 100 gallons each. Each rubbermaid stock tank grow bed will sit on concrete blocks instead of needing a stand. They are deep grow beds and will provide lots of filtration for the money. I like deep grow beds for aquaponics. The 100 gallon stock tanks cost only a tiny bit more than the 50 gallon stock tanks which are almost the same footprint but would require a stand to bring them up to a nice working height. Sure the deep grow beds require more media to fill them but they provide more filtration. Filtration is all important in Aquaponics. Think of the deep grow beds as providing more space for media.
At the time of these pictures, there was only one grow bed leaking. We had to remove gravel from one grow bed to replace it and we had to shift another of the grow beds over to make room for two stock tanks in the middle of the aquaponics set up.
100 gallon Rubbermaid tanks sitting on concrete blocks are high enough up that they can drain into an aquaponics sump tank that is sunk most of the way into the ground but with a top rim up above the ground surface to keep heavy rains from washing into the tank. A 100 gallon stock tank up on concrete blocks is a comfortable working height for most people to work with the plants