The systems I teach how to build in my ebook, Step by Step Aquaponics, you can either use pressure-treated wood or angle iron. Here in Honduras, pressure-treated wood is not readily available. Metal and welders are on every corner. In all our systems we build now, they are made out of 2 1/2“ angle iron. To this date, we have had no issues at all. The dimensions of our rack systems are in my ebook.
I get contacted by people all around the world consistently and I understand because of an economic factors, some people are forced to reducing the cost to their system. They have a propensity to go cheap. This is an area I would not go cheap. To make a poor base will cost you more in the long run with time and money. I have a friend that used pallets to set his grow beds on. Guess what? He was ripping out his pallets out in 2 to 3 years later because they were rotting. My friend is a great guy, but sorry, this was not thinking forward.
Then set all my posts into the hole. If you use angle iron, you will need to ensure you weld a foot on the bottom of the post. This will ensure your post doesn’t slip through the gravel in time. After pouring the concrete and it has had plenty of time curing, you are now ready to build your system on top.
I know this blog post was short, as stated before, this is one of the most important steps. You don‘t want to go back and rebuild your foundation and rack system. Literally, tearing apart your aquaponics system and begin again or constantly be adding band-aids to it by patching and shimming.