biological cycling / 3

Goldfish are my least favorite type of fish; they’re total jerks who steal all the food, they love to bully plants and other fish in the aquarium, and probably worst of all, they poop so much. That last reason, combined with the fact that they are just ridiculously hardy (as in hard-to-kill) is probably why I’m using them to kickstart the biological cycle for the tank.

Picture of the tank taken on 2/16/16

After the big water change, I introduced the goldfish to the tank (along with the single plant). I let them be for a few days, and then transferred some of the spinach seedlings to the growbed. The other plants hadn’t grown in quite as well yet, and I figured spinach would be a good one to test things out with.


Freshly planted seedlings 

I was a little worried at first because the whole transfer process felt a little clumsy to me; I gently pulled the seedlings out of the soil/compost and washed out the roots, then created a ‘dimple’ in the growbed, stuck the seedlings in, and then covered the dimple back up. After checking in today though, I feel alot better – the seedlings seem to have taken hold pretty well in the growbed. I’ll transfer some more spinach this afternoon, and possibly some cilantro as well.

That both the fish and the spinach seem to be doing okay is indicative to me of a few things; first, that nothing disastrously wrong has occurred! Yay! Second, it makes me pretty confident that the biological cycle is being established successfully – I’m fairly certain that within a week, the system will be mature enough to host new organisms (fresh seeds directly planed in the growbed, and a larger community of fish).

Looking ahead, there are a couple of ways in which I’d like to expand the project. I really want to introduce vermiculture to the growbeds, most likely in the form of red composting worms. They would help remove larger organic matter (such as dead root systems or physical fish waste) and convert them into vital minerals (a common deficiency in many aquaponic systems) that the plants can absorb. I also want to culture daphnia to feed the fish, as not only a supplement to their likely diet of dried fish foods, but also a more accurate replication of what they might eat in their natural environments. I’ve also decided that the aquarium will be a planted tropical freshwater community aquarium, which essentially means there will be a variety of fish (guppies, tetras, danios, rasboras, etc.) and plant species (swords, anubias, dwarf grasses etc.), as well as invertebrate (shrimps and snails).

I’m so excited! Whether or not all of this will happen before or after spring break is yet to be seen, either way, I can’t wait!


a big jump: putting it all together / 2.2

So our last post left off with a big (empty) tank, two growbeds with working bell siphons, and a  pump with plenty of piping to connect whatever gets put together. There were only a few more steps to reach a finished and, more importantly, functional aquaponics system!
There was some more manual-labor work to be done, such as setting up the planks on top of the tank, and cleaning the gravel before adding it to the growbed.

Spinach seedlings four days after planting

Before I started to work through those tasks, first I planted the seeds to get an early start on the vegetation that would be grown in the system.

With help from Ms. Poulin, I chose cilantro, basil, arugula, and spinach seeds  from our Biology department stock room and planted approximately 30 seeds in a 6 by 6 pod plastic growing tray. I chose to grow the seedlings separately  just because I thought it would be easier to transfer the seedlings into the growbed than try to start them in the system before the biological cycle had been set up, and because the timing happened to worked out perfectly.

I planted the seeds right before the long weekend (February 5th), and when I came back (February 10th), all but the cilantro had sprouted. I chose to plant more spinach and basil for my second batch of seedlings, as they were growing especially well. Hopefully I’ll  have a substantial amount of vegetation to transfer soon.

Setting up the rest of the system was pretty straightforward, if quite time consuming and also just physically demanding. I actually worked in a pretty inefficient order that involved having to needlessly move around lots of heavy objects (like fully filled growbeds), but essentially, the planks were set up first, then the two growbeds, then the gravel, and then the plumbing system. After everything was in place, I played around some more with specific pump pressures and plumbing/drainpipe set ups to get the bell siphons working well. I even managed to get the aquarium light fixture to fit, so the #aesthetic will be #onfleek.

It’s done! I did a big water change after everything was set up, and have five minnows which will hopefully be hardy and flatulent enough to get the biological cycle going once I introduce them to the tank. After letting that cycle for a while, I’ll transfer the seedlings, and then expand the aquaculture system, and that’ll be it!

Finished set-up

I’m looking forward to making this a thriving ecosystem! After all, it’s the living  (edible) things that will make the entire system interesting (at least for me).



a big jump: bell siphons and growbeds / 2.1

Construction attempt #2 was quite the adventure.

I transferred from a “nutrient film technique” circulation system to a split-flow “bell siphon” drainage system, which required several new materials: brand spankin’ new growbeds, all the components required for the bell siphon, and additional plumbing parts for the new configuration. In addition, our tool kit upgraded to include a big fancy drill with all these different bits and attachments and other things I’ve never even heard of before.

The first step of the process was to attach fittings to the grow beds which would hold the standpipe and drainpipe.

A drill (1/4″ bit) with a hole saw attachment (7/8″diameter), and a male and female thread-to-slip PVC attachments (1/2″diameter) with two #16 O-rings.

Shout out to Dr. Kemp for letting me work on this in the classroom while her biology 580 class was simultaneously dissecting cats about four feet away from where I was working; she also gave me a few tips about how to operate the drill and not bore a giant hole into my own hand. The first growbed ended up slightly cracked, but the second went really smoothly, with secure fittings and no detectable leaks.

Once the fittings were in place, PVC pipe could now be attached to form (1) the standpipe, and (2) the drainpipe. Additional PVC was used to (3) modify the drainpipe and create  (4) the media guard. 

Mr. Josef cutting PVC

All the separate components needed for this section required a visit to our school’s theater workshop (“The Shop”), where Mr. Josef and his assistant helped cut the PVC piping to size.


We used 2(1/2)” diameter PVC for the media guard, 2″ diameter PVC for the bell siphon, and 1/2″ PVC for the standpipe and drainpipe. We also cut out a bunch of smaller sections of both the 1/2″ diameter PVC and 1/2″ diameter CPVC to use as part of the plumbing system.

Mr. Josef also provided two planks which were used later on to create a rack across the top of the aquarium to support the growbeds.

I drilled 1/8″ diameter holes to a height of 1″ on a single side of  each of the bell siphon pipes, as well as small ‘teeth’ at the very end, and a mixture of 1/4″ and 1/8″ diameter holes for the media guard.

A bell siphon relies on an air tight ‘bell’ over a standpipe. When the water level reaches that of the standpipe, it generates a vacuum within the airtight space, creating active suction that drains the water out of the growbed until the water reaches a certain level (the top-most notch in the bell), at which point air re-enters the bell, the pressure equalizes, and the suction stops. This process is repeated to create a constant fill-drain effect.

Finishing the bell siphon and growth bed construction required lots of minute adjustments.

Testing a finished growbed

Factors such as height of the standpipes, suction (determined by drilled holes) of the bell siphon, media guard configuration, drainpipe configuration, and pressure of incoming water flow, all had to be played around with to get the bell siphon to work. It took me over a week, but eventually I had two empty grow beds, each equipped with functioning bell siphons and media guards.