Now that we’re all caught up here and the weather is getting nicer, we’re looking to get back up to speed with the project. Here’s the roadmap for the next couple months.
1. Finish the inside
We need to finish the walls and flooring to cover the insulation and give us a bit more airspace between the exterior wall and the interior.
The trick with the wall finishes is that we need to plan on the interior being humid a lot of the time. This rules out drywall for the most part. We’re thinking of using galvanized barn metal for the lower half of the walls, ceder/pvc for trim, and cedar or engineered paneling for the top half of the walls.
The upstairs roof portion of the dome will be paneled or ship lapped as well. Doing this only requires cuts for one angle at a time and for length. This will be a lot easier than setting up jigs again, plus it will look nice.
The base building floor is going to see a good amount of traffic in and out and we weren’t super comfortable of using a paintable coating. We’ll most likely use some form of vinyl tile or roll stock.
2. Finish the electrical
We ran most of the electrical downstairs before we spray foamed, but we haven’t touched the upstairs yet. We’re going to use exterior wiring techniques for the dome due to the humid/hot/cold swings it’ll see throughout the year. This means all wire is going to be in conduit then ran to sealed switch boxes and exterior outlets. This not only will help keep our electrical in good shape, but it will allow us to modify it easily depending on our changing needs.
3. Work spaces
We’re going to build some simple work benches and storage that will make help keep us organized for the rest of the project and help us plan our space a bit more when adding anything else we need.
4. Grow beds
We’re going to build our angled grow beds out of wood and insulate with half inch foam. The insulation will help us keep the water temperature from fluctuating wildly which will stress out the fish.
Typically wood grow beds are lined with pond liners to waterproof them, but these are bulky to use and expensive. We decided we are going to make a mold and line the beds with a 1/2 inch coating of food grade pourable silicone. This will save cost and be water tight.
5. Water treatment
Before we can install plumbing, we need to build out the various steps for removing the fish waste from the water.
Clarifier
The clarifying step removes larger solids from the system. We’re going to build a small lamella clarifier. This will utilize a series of parallel plates to increase surface area and give the solids more time to settle to the bottom where they can be removed.
Mineralizer
The mineralizer is really just a container with zig zagging channels that the water has to travel through while we pump a bunch of air into it. This will help break down any residual solids and small particles into trace minerals.
Biofilter
The biofilter is what converts the fish urine (ammonia) into nitrates. This is basically a barrel filled with plastic pieces that provide lots of surface area for bacteria to grow. This bacteria is what produces the nitrates and filters the water.
6. Plumbing
Now that we have all our components, we can start plumbing everything together. Most of the components gravity feed into each other, but we’ll have a large aquarium pump that will pump the water upstairs to the grow beds. The plumbing design is still a work in progress and we’ll have more details when we get closer to this step.