Building Plywood Tanks

I get these 40"x47"x36" plywood boxes from a juice factory for $5.00 each.  I cut the shipping boxes into thirds or in half, and add bottoms to the sections as needed.  I look for discounted irregular plywood to save money (generally 1/2 price).

To build the basic plywood box would cost about $60 if you used 3/4" plywood at about $25 per sheet.  These come banded with heavy metal corners.on a pallet.  It's hard to beat these juice boxes built with high grade 3/4" - 5 ply plywood. It takes about 2300 ml of resin per tank at $50/3.5 liters

Fiberglass makes these tanks durable and clean.  Cost was about $60 per 40"x47" tank.

I'm filling this tank with water to test for leaks

The deeper tanks on top will be wicking beds.  The shallow 12" tanks underneath will be bioponic grow beds. 

I'm not concerned about toxins from the fiberglass resin.  If you are then use LG-730 Mono Epoxy Pool Paint or Pond Shield. for the finish coat  It will add $10-$20 per tank

These same tanks would cost only  $20.00 each if pond liner were used.
Box        - 5/2    =   2.50
Liner     - 100/9 = 11.00
Bottom - 12/2   =   6.00


After one year of use I found that the bulkheads needed to be tightened.  I expect the wood expands and contracts with changes in humidity which eventually caused them to loosen.