It’s been a few more weeks since my last update and I’ve been super busy learning some plumbing and figuring out the best configuration for all the water treatment steps. We’ve got the water flowing and I’m super stoked to go over the details. This was a lot of fun to figure out.
Originally I thought I had planned for enough space in the basement to allow me to put all the mechanical filtration in a line to simplify the plumbing layout. Turns out, I forgot about this and didn’t install the fish tank far enough back, so we had to make do.
As you can see, the layout is a bit atypical and we’re cramming a lot of stuff into a small spot. Disclaimer, I know the sizing of the mechanical filtration is way oversized, but I wanted to use 55 gallon drums just to simplify the build and give me more room to work within each component. This amount of filtration is probably good for around a 2000 gallon fish tank instead of my 600 gallon tank.
Ok, from right to left we have the 600 gallon fish tank, then it feeds directly into the mineralizer, then into the biofilter, then into the sump where the pump is located. I am still missing the clarifier component. Once that is complete, the fish tank will feed into that and the mineralizer will be fed by a much slower feed.
The components
I realize that I’m rattling off some terms here and I’d like to explain each component in further details. I’ll go over the builds in a later post, but I don’t mind answering any questions in the mean time.
Clarifier
We’ll start with the thing we’re missing. In a previous post, I discussed how we were going to build a laminar plate clarifier out of stainless steel.
The idea is that water goes in the left side and travels down under the bulkhead. The angled plates slow the rising water and allow the solids to settle to the bottom. Once this part is done I’ll build a wood frame to support it and make the plate inserts from poly cutting boards. The settled waste will be slowly sent to the mineralizer.
Mineralizer
I’m using a modified compost tea brewer design to circulate and suspend the solids from the clarifier to produce trace minerals such as iron and phosphate. The slow flow from the clarifier to the mineralizer should give the bacteria enough time to consume a good portion of the solids.
We have a few things going on here. The first thing you’ll notice is that we’re dumping the water from the fish tank directly into the top of the barrel. We’re really only going to do this if we need to bypass the clarifier. Normally the waste enters through a small half inch inlet at the base of the barrel. We then use air stones in the two side pipes to percolate the waste up to the top of the barrel so it can continue to cycle. The lifted water flows in a circle to help keep the solids suspended so they can be broken down by the system’s bacteria. In the middle we have our still well where the clean water will slowly rise to the stand pipe where we can syphon it off and add it to the main flow.
Biofilter
The biofilter is where the magic happens. Did you know that fish excrete their liquid waste from their gills? I sure didn’t. This is where we take that waste (ammonia) and convert it to nitrates.
A biofilter sounds like something high tech, but all it is here is a cheap toy tote from Walmart with some holes drilled in it that we filled with bio balls which we sprinkle our water over. I found a great deal for bio balls on eBay, 4000 balls for the price of 800 elsewhere.
The purpose of the bio balls is to provide a large surface area for our bacteria to grow.
Sump tank
The sump tank is pretty simple. It’s just a 55 gallon drum where our processed water can gather so it can be pumped to the grow beds. I added a stand pipe to the sump tank because if you turn the pump off the water would overflow before it stopped flowing.
We are using a DC aquarium pump that can push around 3200 gallons per hour and is able to do so up to a height of 18 feet.
Grow beds
We installed the 20 mil poly liner in the grow beds and dropped inlet pipes in each bed. The open ended T fitting is a DIY venturi aerator. This injects air into the water as it passed through the fitting. The basic concept of the venturi effect is that you create a pressure differential by restricting the flow at a choke point and increasing pressure. This creates a suction that mixes air with the water. All I did here was narrow the 1 inch water line down to 1/2 inch and extended the reduced section passed the T so we didn’t get any splashing. As you can see we’re getting some nice bubbles.
The grow beds are filled to a depth of 12 inches and we’re currently leaving it open to the sunlight so we can hopefully warm the water enough over the next few days so we can add fish. The water comes out of my well at 50 degrees and we need it above 65; preferably above 70.
The water enters from the right side of the beds and slowly makes its way around to the stand pipe where it travels back to the fish tank to cycle again. We can control the water depth by extending or shortening the stand pipes. All in all, it took around 4 hours to fill the whole system up. There’s around 2000 gallons of water in the entire system. I need to add a ball valve on the center bed’s water supply so it can be restricted to allow a little more water to flow into the much larger perimeter bed.
Initially I filled the system up and then drained it to do a preliminary leak check and to flush all the plastic bits, waste, and excess glue out. All of the tank drains and waste outlets are attached to a 2 inch drain line. We just vent this down my hill. It only takes around5 minutes to empty the whole system this way.
What’s next?
Every time I finish a large portion of this project I tell myself “we’re almost there!” Alas, we still have some problems to solve, more stuff to build, and at some point I need to learn to grow plants.
- I need to come up with an efficient and cost effective way to control the water temperature so we don’t freak the fish out with fluctuating water temperatures.
- Need to install some smaller fish tanks to quarantine any sick critters and also to keep young fish.
- The foam floats and net baskets need to be added so we can plant stuff
- Need to build a small seed germinating cabinet.
- Install a laundry sink upstairs and run water lines/drains
- Add work benches and storage where there’s room.
- floor drains need to be installed upstairs an downstairs.