This is the only large plywood tank with a sump under the stand, and it's a little over half the size of your tank that I have seen. FB DIY Monsterfish Keepers. All the other tanks are built on a solid plywood foundation.

Another administrator on that forum has a Youtube channel. He built a 1500 gallon plywood tank.
All the BIG plywood tanks I have come across on forums are on built on a solid plywood foundation, with the exception of the tank posted above. Have you considered building your plywood tank on a tubular steel stand? My acrylic tank is only 15' long and considerably lighter than you tank will be. Our stand is made from 3 1/2" tubular steel. Here it is after my husband fabricated it. It looked a lot better after we got it powder coated.


Another administrator on that forum has a Youtube channel. He built a 1500 gallon plywood tank.
All the BIG plywood tanks I have come across on forums are on built on a solid plywood foundation, with the exception of the tank posted above. Have you considered building your plywood tank on a tubular steel stand? My acrylic tank is only 15' long and considerably lighter than you tank will be. Our stand is made from 3 1/2" tubular steel. Here it is after my husband fabricated it. It looked a lot better after we got it powder coated.


