My Bachelor Thesis is based on creating a self-regulating Aquarium. Can you guys help me brainstorm a plan?

[jta117]

Look up the principles behind devices like the ReefBot, mastertronic, kh keeper, trident. Throw in a combination of temperature controller and heater, maybe figure out some nifty way to automate salinity readings (those probes suck), a general ph probe, and a bunch of dosing pumps and automatic water changer. Maybe even include some way or protocol to regularly send in water samples to an ICP testing company or your own dedicated ICP machine.

If you are only concerned with the theory and not actually building (or paying for) any of this, that makes it much much easier.

Yeah, for now its all theory. Just theory aimed for a Smart Aquarium.

 

[keithIHS]

I smell a commercial motivation behind this. Easier reef-keeping means more sales. I think a company approached the prof looking for ideas. What's the next step after Apex et. al.

 

[keithIHS]

FYTI: I had a DIY 70 gal saltwater many years ago which was a disappointment and got away from the hobby. I set up my current tank back in October. It's 120 gallon, with a 40 gallon sump, Clarisea roller filter, skimmer, refugium with green hair algae (because I killed the algae I wanted), and heaters and return pumps of course.
Tunze Osmolator auto top-off (ATO) to replace evaporated water. It's a 6-gallon bucket that I have to refill every 4-5 days. It uses an optical water level sensor and back-up float switch, with logic to turn off if it runs too long. And I have an RODI unit feeding a 50 gallon storage tank for fresh water. I have a 2nd 50 gallon tank for salt water. I use a commercial salt mix (Tropic Marin Pro), which has all the right chemicals. Except it mixes to an alkalinity of about 7 dKH, but I want it to be about 9, so I add baking soda to the new water (via pre-mixed solution). Another reason I've been testing alkalinity. Recall that pH is determined by alkalinity and dissolved CO2. I want my alkalinity up a little to help with pH. Thinking about running an airline from skimmer to attic.
I also have a Neptune Apex with temperature, pH, salinity, and ORP sensors, and a Neptune auto feeder. The ORP is probably not worth much except for possibly to let you know if some large animal dies and is polluting the tank.
I only have 2 clownfish currently. They've been in there since mid November. There is some rock and sand in the aquarium, and of course the bacteria are doing their thing. The rock and sand was rather sterile, so not much biodiversity. I have some live sand, a shrimp, serpent starfish, and some hermit crabs in quarantine in another aquarium which will go into the main aquarium once I'm assured there aren't any obnoxious pests.
I currently test for alkalinity, pH, Nitrate, Phosphate. Don't really need to test for any of those with fish only, but I'm trying to learn how things work. I did test for Ca and Mg, but stopped because they don't change. There aren't any organisms that use Ca and Mg to build shells or skeletons so no sink.
Alkalinity has been interesting. It shouldn't get used up, because like Ca, it's used to build shells and skeletons, and I don't have any. Still, it drops about 0.5 every week, so I dose a solution of baking soda. I've been told that something in new tanks (bacteria? algae? diatoms?) will use it. My rock and sand have been "cycling" since last March, so I would have thought that would take care of it, but no. Maybe because I turned the refugium light on only a few months ago.
Interestingly, pH is determined by alkalinity and atmospheric CO2, which in a home can be higher than outside due to humans and animals and maybe other like burning propane for heat or cooking. The pH in my tank varies between 7.9 and 8, which is a little low, but probably OK. Coral will grow better at higher pH, like 8.3.

 

[keithIHS]

One simplifying factor, that @xiaoxiy alluded to, is that the ocean is pretty consistent as to chemistry. The Red Sea is a bit higher salinity, but not enough to worry about. Temperature varies a bunch of course. So maybe tropical, temperate, arctic would be sufficient...or just do tropical (78 deg F) for now, document the assumption, and move on

 

[keithIHS]

Look up the principles behind devices like the ReefBot, mastertronic, kh keeper, trident. Throw in a combination of temperature controller and heater, maybe figure out some nifty way to automate salinity readings (those probes suck), a general ph probe, and a bunch of dosing pumps and automatic water changer. Maybe even include some way or protocol to regularly send in water samples to an ICP testing company or your own dedicated ICP machine.

If you are only concerned with the theory and not actually building (or paying for) any of this, that makes it much much easier.

LOL, I went through a lot of grief trying to get my Apex salinity probe to read correctly. This is something I've learned over and over again in engineering. Instrumentation is really hard. Accurate salinity measurements are possible, but you need to take special care. All instrumentation will give incorrect readings if you don't use them "correctly". All instrumentation will give inaccurate readings at some point and will fail. Calibration is very important. Where I work, using uncalibrated instrumentation is a serious lapse that doesn't get any sympathy if it results in a failure. Search for Randy's DIY salinity standard and check this out: https://www.reef2reef.com/threads/a...calibration-and-tc-factor.718971/post-8412445

 

[keithIHS]

Which raises another issue. What is your requirement for accuracy, repeatability, reliability? This may be the responsibility of whoever is designing the controller, but you'll need to figure out, for example, what the different animals require for temperature stability. Can they handle a 1 degree swing? a 5 degree swing? Over a day? a month? a year?

 

[keithIHS]

For food I bought 4 different blister packs of cubed frozen food. One of those packs is a sampler. I take a cube from each pack, and put two cubes in each of two 12 ounce squeeze bottles and fill with aquarium water. I let them thaw and break up the one or two cubes that have a gel binder. I then feed 1.5 ounce 3 times per day, alternating bottles. I store them in the refrigerator so they won't spoil. I also have an auto feeder that dumps a very small number of pellets 3x per day. This is certainly way more food than two fish require, but I have the roller filter and I'm trying to condition my tank for more fish. A wrasse and royal gramma coming next week, and small clean up crew in QT.

 

[chadfish]

Correction: make it simpler than you think you should and in the unlikely event you have extra time you can add to it.
It's all about the water...and light for corals, algae, anemones, and other photosynthetic organisms.
Dont forget about oxygen and CO2. If you have lots of flow, only needed for coral or some types of filtration, gas exchange happens, but if low flow, you will need to do something about it.
Remember, you're not going to be graded on how well you understand aquaria but on how well you apply what you've been taught. Focus on the ME aspects: DiffEq, controls, thermo, heat transfer, maybe fluid mechanics (pipe flow and head loss), instrumentation, power, etc. Chemistry is important but it's not your area. Don't get bogged down by it. Chemistry is a great place to simplify.
Keep it simple.

This is exactly correct. Keep it as simple as possible and apply your new ME knowledge. You get extra points for creativity or out-of-the-box thinking, but they really just want to see how you apply what you learned to a real-life problem.

 

[stacksoner]

If you look at the thousands of posts on the various forums here, you'll begin to understand how difficult it is to replicate a healthy living oceanic reef in a small controlled environment.

In my experience, the best way to have an incredible tank is to hire a really great maintenance person to care for it 7 days a week