long overdue wrap up /9

So this will be my last post before turning over the project for next year!

My biology 580 group, which conducted our final project using the aquaponics system, affectionately dubbed “Snail Squad”

I decided that instead of barfing out my sentiments and thoughts after almost two months of inactivity, I would just post my final reflection on the project I submitted as part of my digital portfolio (also available to check out on the canvas ePortfolio). Here it is!

Terrence Xiao


Final Reflection


The story of this project, if told through a novel, would probably (I’m 94.2% sure) win a Pulitzer-prize. Why wouldn’t it? Its plot is simple but nuanced, the progression is complex yet holistic, the story overall is relatable, yet not so much so that it lacks depth, and the characters, especially the protagonist, is likeable to the extreme.


In all seriousness, I think that the ‘story’, so to speak, of this project, is one of its most powerful components. It’s the one that I share in almost every presentation, no matter the venue, and it’s the one that people seem to find most remarkable and interesting – being able to start with an interest and develop it into something academically and social relevant, and then being able to take that idea and explore it and share it with others, seems like a nerd-fairytale. Actual events, were, of course, more complicated than that – outside of the project, the tumultuous life of an average Phillips Academy student often intruded, restricting available time and energy. Even within the project itself, there were many obstacles that had to be overcome; I can still remember the terrifying crack of plastic the first time I tried to drill a hole through one of the grow beds and ended up almost taking off a finger, nor will I forget the momentous rush of happiness when the first ever bell siphon cycle successfully completed (immortalized in hideous snapchat selfie sent to close friends captioned “If finally worked!”). Of course, it was all of the little moments, positive or negative, that completed the story. Ultimately, the entire experience was incredibly formative for me as a student, not only in terms of my understanding of aquaponics, but also in my appreciation for education and the learning process.


The ‘story’, to others, is accessible in a number of ways. They can hear me speak, either informally or during a presentation, they can follow along themselves on the WordPress blog, and they can explore any number of written documents, logistical or otherwise, or visual presentations (comprehensive movie coming soon). I can’t speak to what Construction and Study of Integrated Aquaponics System brings to other people, but I can imagine that it’s different for each individual. For the freshman, it may bring a sense of wonder (ah yes, that spark of hope that we all carried with our innocence before it was brutally snuffed out by the never ending cycle of coffee, all-nighters, and homework) at the resources and possibilities this institution offers. For the senior, it may offer a fresh perspective on world issues that we, as newly minted graduates, will soon have to struggle with (this is still terrifying to me). For the teacher, it might highlight a learning process available to students here, and serve as a reminder that in an environment chocked full with tests and essays, sometimes the most substantial learning, even serious fancy-pants academic learning, can take place outside of the classroom. For the aquarium enthusiast, this story may be one filled with hope, as it was for me, that the underwater world with which they are so fascinated can in fact be made into something of relevance on a larger scale.


As this year comes to an end, the phrase that I would use to describe this project is not ‘incredibly cool’, or ‘amazing’, or ‘downright revolutionary’, as I’m sure everyone else would, but instead unfinished. For all that this project has achieved, I’m so happy and grateful that its impact will continue beyond this year – through the influence it had on me, through the conversation it embodies about sustainable production on our campus, and through its continued use as an educational tool.


This project has changed me as a student, by improving my understanding of aquaponics, yes, but also by challenging me to engage with my learning at a more fundamental level than did any of my other schoolwork. There are lots of ways that this project has influenced me at an individual level, but I’m choosing to focus on the aspect of hands-on, project-based learning because I think it’s most distinctive and directly attributable to this unique learning process.


Before this year, I had never designed and structured a core aspect of my academic curriculum. I had never conducted independent research under evaluation at such an extensive level. I had never applied for and received a grant for said research, never constructed something as tangible, both physically and conceptually, as an aquaponics system with said grant, and certainly never created and maintained an entire infrastructure supporting said system to impact a community as unique and merited as Andover’s.


I realize the dramatization inherent with describing the project that way (it could easily have been rephrased as ‘googled some stuff, built some things, talked about it’). It’s still pretty cool though. I don’t only feel more knowledgeable about the subject I set out to explore over a year ago, but also empowered by that knowledge to actually do something about it. That’s something that’s been unique to my own Andover experience – nothing else that I’ve done here has impacted me in the same way.


My biggest takeaway from the project is that the disconnect that students often feel from their schoolwork is artificial and self-constructed. If I can find a way to talk about aquaponics in an Asian-American Literature and Film senior English elective, then anyone can find a way to explore their own passions in a serious academic capacity.


The first thing people tell me when they learn about my project is ‘wow, that’s so cool, I didn’t know you could do that’.  Which is great, because part of what I’m trying to convey is that students should take advantage of the incredible resources that have available to them to broaden their academic experience. The point that I think tends to be overlooked, especially by certain audiences, is that the work that I’m doing is also relevant on a much larger scale (I hope). Amongst my peers, the big three distinctions in life are between ‘things you like’, ‘schoolwork’, and ‘the real world’. These distinctions basically mean that schoolwork takes precedence over personal interests, and that it only serves as a stepping stone to matters of actual importance. This project, at least for me, debunks those distinctions completely. It’s not just some scaled up version of a hobby into something that happens to fit within my academic curriculum, it’s also something that I can and will continue to explore in the future that could conceivably be of relevance in ‘the real world’. That’s something I don’t think a lot of other students could say of their schoolwork, which is unfortunate. It’s not easy to characterize whose fault it is, and there is certainly a heavy push within the community by many parties to change this modus of learning. My hope is that this project stands out as an example of how such change can be achieved.



Go aquaponics! This has been such an enriching and meaningful experience for me overall – I cannot emphasize enough how much it has shaped my Andover experience.


snails & freshmen /8

Two major updates since the last post: first, I’ve successfully given my first two ‘lecture’ presentations to other students! Second, the tank has also become victim to my BIO580 group’s ecology project.

The presentations I gave were to Ms. Milkowski’s Biology 100 classes, and encompassed several different themes. I tried to explore both the science-y side of aquaponics, mostly through discussions about nutrient cycling and other ecological principles, but also did my best to convey the ‘project-y’ part about the system. One thing that I really wanted to emphasize was that this was a project that any student could conceivably undertake, and that the entire process was driven by my own interests. The Abbot Academy Association and Abbot Independent Scholars Program are clearly the two centerpiece enablers of the aquaponics project, but equally important (in my opinion at least) was the encouragement from my peers and mentors and support from the community in general.

Tomorrow I’ll be giving another presentation to a different class: Science 420 – Food and Agriculture. It’s to a slightly more mature audience, so the focus of the presentation will be aquaponics and permaculture as a potential solution to the global food challenge.

Other big presentations coming up include the talk at the Science symposium our school hosts for the Bio 600 students (May 22nd), and also a possible presentation to the board of the Abbot Academy Association.


Fish interacting with newly introduced albino myster snails; Image courtesy of Olivia Xiong

My Biology 580 class is wrapping up the year with group ecology projects; my group is studying the effect of increased snail populations on a controlled ecosystem. We found it very convenient that there happened to be such a system already set up available for us to use 🙂

Our hypothesis is that the increase in snail population will ultimately cause an increased amount of free floating algal spores because the snails would consume competitive algal species. We ordered mystery snails through the stock room and have been steadily adding them to the tank – so far, they seem pretty happy. Our data so far loosely matches up with the hypothesis; we’re taking measurements of algae levels with a spectrophotometer – it’s pretty simplistic but  effective.

Ecology projects and presentations aside, this year is almost over! There are only a few more things to worry about, which I’ll explore more fully soon – succession (what happens to the tank at the end of the year), video, final reflection, etc.




presentations /7

Picture of the arugula and cilantro taken on 4/29/16

Not much in terms of the physical development of the tank has been happening recently – lots of maintenance and cleaning etc. Current fatalities consist of two neon tetra and an albino bristlenose pleco, which is certainly unfortunate, but  understandable.
After the ~two week period of cloudiness and haze that usually comes with a new tank, it seems as though the system has stabilized.
The reason the physical system has been at somewhat of a standstill has a lot to do with the focus of the project this term; Spring term is all about community outreach – taking the system and using it to engage with (mostly) students and faculty members. This ranges from giving presentations about the project to various student groups and dedicated audiences (like the NEST presentation) to using the system as a learning tool in various classes.

Another thing I’ve been focusing on recently has been the issue of succession, albeit somewhat lazily. While I’ve yet to meet with Mr. Holley about the issue, I would really love it if the system could survive the summer and return next year as an established part of the Gelb learning toolkit. I spoke with Max Davis about the possibility of not just taking care of it, but using it as a platform for future IPs and other projects, and the overall outlook seemed quite hopeful.

This has been somewhat of a short post, but there hasn’t been much in the way of noteworthy events. Coming up are the first of the class presentations, so expect more information coming soon about how those go.

new (stressed) fishies! /6


Picture of the tank taken on 4/6/16

You’ll see a school of eight neon tetra in the bottom left corner of the tank, a school of seven giant danios in the right middle of the tank, and a school of eight golden barbs just beneath them hiding close to the plant. You might also notice one of the two albino bristle-snout plecos suckered onto the front glass pane towards the left/center of the tank.

YAY! The plant species currently in the tank are, in no particular order, argentine sword, hairgrass, rorippa, and what I believe are moneywort and ludwiga needle leaf. There’s also the same anubias from before and two pieces of vine and drift wood with some kind of hygrophilia (I think) binded to it.

I really want to plop a nice big gray stone in the back right corner to round out the ~aesthetics~ of the tank, but that pretty much sums it up.

The fish are still a little stressed out as it’s only been a few days since their introduction to the tank, but we were able to get past the first-night hump with no fatalities so I’m pretty confident they’ll acclimate and settle in well. As of right now, the only thing that indicates their stress to me is their tendency to stay at the bottom of the tank and their lack of schooling. Other things such as pH, ammonia levels, and temperature, should be OK.

Speaking of which  – I took some said measurements over the past few days and the results have been pretty good: pH and ammonia levels were between 6.5-7 and 0 – 0.5 respectively before putting the new fish in, and were between 6.0-6.5 and 0.-0.5 respectively just a few days after. These results are pretty ideal, although I’m not sure what might have caused the drop in pH – I reckon it might be a combination of increased biomass and stressed fishies (they’ve been known to diffuse ammonia through their gills). If it stays low, I’ll have to look into it more, as the ideal pH is around 7.

Test strip readings for daphnia culture

Something I totally didn’t expect also happened – I took a pH measurement for the daphnia culture just to check that they were working properly, and the test strip turned bright red almost instantly, indicating a ridiculously basic pH level! It threw me off so much that I performed the test twice to make sure. I have absolutely no idea why a thriving daphnia culture would exist in such a basic environment, while showing regular levels of ammonia (between 0-0.5), but it may explain why my other attempts to start up daphnia cultures have failed thus far.

I’m hoping to get some more species in the tank soon – especially ones to take care of the pesky algae growing on the glass (it’s the reason the tank seems a little mucky). I actually ‘borrowed’ two snails from one the school’s tanks (shh) to help out with that – it shouldn’t be a problem, as snails are usually seen as pests in tanks anyhow.

Picture of arugula taken on 4/9/16

In terms of plant life – the arugula is KILLING it. Cilantro and basil are growing pretty well too, but the spinach is still struggling.

An ambitious plan that I went to set into action is set up hydroponic grow lights to equalize access to sunlight, which I think is a huge factor affecting the plants’ growth right now.

Anyhow, the ‘failure’ of the spinach is really more of an opportunity to understand more about plant growth in aquaponics systems – expect future experiments to learn more about said subject!

I know this is getting to be a bit of a long post – my next one should cover the progress of presentations so far.

tl;dr NEW FISH! Happy days.


we’re back! / 5

So basically, aside from literally everything dying, the one thing that I really hoped wouldn’t happen over break did happen…

The pump somehow got flipped over, such that the water-sucky part ended up face down in the substrate; because of this, water flow was greatly reduced, and as a result, there wasn’t enough pressure to start the siphoning effect in the growbeds. Basically, the entire circulation system stagnated.

For such a serious issue, we actually got off pretty lightly. We lost two of the goldfish (there are six left), and all of the spinach kind of withered up and died. Way more water had evaporated than I expected, and the remaining half-tank of water was yellow and cloudy. Also, there appeared to be an algae bloom in the right growbed (it received the most sunlight), likely caused by the stagnant circulation. Everything else seemed to be okay.

The systems been up and running for a little over a week now, and everything seems to be getting back on track. I’ll take pH and ammonia readings later today just to make sure that nothing is disastrously wrong, and hopefully we’ll be able to continue developing the system throughout this week (more fishies!).

On a side note, I was initially really worried that the red composting worms would have drowned in the growbeds because of the broken siphon, but after some digging around, I managed to find at least a few of the lil’ wrigglers still happily alive.

I gave my first big presentation on March 23rd, just two days after we got back from break, in the NEST. For how little I prepared, I think it went pretty well! I got a lot of positive feedback, which is awesome – it’s definitely really gratifying to see how much people take interest in the project.

Future presentations: I’m still a little behind on setting these up, mostly because I want to make sure the physical system is OK first. I’ve reached out to EcoAction about giving a presentation soon, and hopefully I’ll be able to use that as a platform to speak at more clubs (ECOs, EAT). I’m also planning to reach out to Mr. Holley and the biology department about presenting in certain classes (Biology 100, 500, 580; Science 420). I want to make sure I have a well developed presentation that will be relevant at the various academic levels before locking anything in.



spring break / 4

First, I have to clear up an important mix-up with the plants: What I had previously thought were spinach seedlings were actually arugula – I must have switched up the labels after seeding the plants. The growbeds have re-labelled, and all four plant species are now growing well.

Red composting worms in the process of being introduced to the system

In addition, there’s been an exciting addition to the system – Red composting worms. Ms. Milkowski recommended I get in touch with  Ms. Trespas, who has her own vermicompost system, and she was kind enough to donate a few of her own worms to the project! I estimate that between the totally awesome fully grown four inch ones and the teeny-tiny wriggly larvae, there were approximately forty or fifty worms split between both growth beds. To get them in, I simply took big chunks of compost and spread it over cardboard pieces placed on top of the growbeds. Because of the worms’ natural aversion to sunlight, they quickly escaped into a more desirable environment – right into the growbeds. After checking back the day after and not seeing worms crawling all over the outside of the system, I think it’s pretty safe to say they’ve found an ideal environment from which they won’t try to escape.



Biology stockroom daphnia culture (left), 2 liter soda bottle culture (right)

The daphnia culture is returning mixed results – the established colony I’m using which belongs to the biology stockroom seems to be doing fine, but the two other cultures which I’ve tried to start in an old 2 liter soda bottle and the smaller, algae-rich tank don’t seem to be flourishing as I hoped they would.

Flourishing arugula (previously thought to be spinach) seedlings

The system itself seems to be doing just fine. At this point, I think it’s all set to cycle over spring break. Hopefully when I return, the system will be fully established and ready to take on some new aquaculture (it’s currently cycling with eight goldfish). If the plants are grown in well enough, I’ll be able to start harvesting and replanting soon – I decided not to seed the growbed over the vacation because there is already a plethora of seedlings, and I didn’t want to risk overloading the system.

Spring term is looking really hopeful! The independent project was approved, so we’re all set to continue work on the system. Most of next term will focus on the development of this blog, expanding the system, and giving presentations/lectures.

See y’all in a few weeks!

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.

a slow start / 1

Okay, if you dropped by Gelb 109 today and went to take a look, all you’d see is a fish tank filled with water and substrate and nothing else. Believe me, for every bit as boring as it may seem to y’all, it’s as painful for me to see such a big beautiful waterscape devoid of life.

So what’s the deal?

The deal is Winter Term’s schedule is crazy wacky and after construction attempt #1 returned (let’s call them) mixed results, I haven’t found the opportunity to go out and buy new shiny parts to play around with.

The first skeleton model of the plumbing system

Construction attempt #1 actually went okay – the system worked, but the few problems were pretty substantial, and I wanted to do this right. I have the time, and I have the funds, so why not make the system the best it could be?

I started with a single flow Nutrient Film Technique connected the two grow beds with 1/2″ PVC piping. The pump came up from the right side, deposited the water in first grow bed, where it flowed into the second bed and then out the back into the aquarium.

The biggest issues with the design was just kind of keeping everything together – I was working with brittle plastic, a scalpel used for cat dissections (shh), and electric tape, so it shouldn’t come as a surprise that the entire thing was prone to malfunctions, with tons of leaks and also difficult-to-equalize water levels.

I took the system apart and rethought my design – the few things I wanted to focus on were (1) quality of construction and (2) water level management.

So here’s the new plan: split flow into separate growth beds (to eliminate the need to somehow connect them). Bulkheads and drilled, measured holes for the PVC piping instead of playing around with a scalpel and electric tape. Finally, more substantial grow beds that won’t break down or tear when messed around with. In addition, I’ll be trying my hand at building a bell siphon drainage system. If that all sounded like technical jargon that was a little hard to understand, that’s because it was – and trust me, it’s confusing for me too. This should be fun.

Next post will likely cover the construction process, but hopefully soon we’ll have the system up and running so we can start talking about the real meat (pun +1) of the project: fishies and veggies.

Stay tuned!