Aquarium Monitoring Station
eiplanner
Posts: 112
I have a 100 gallon, saltwater, reef and fish aquarium that requires:
- Weekly water parameter testing for pH, Nitrate, Nitrite, Ammonium, Salinity, Copper, Magnesium, Phosphates, Iodine and possibly others.
- Daily water make-up for the evaporation.
- Feeding of frozen foods twice daily.
- Timers for the intense lighting.
- Emptying the protein skimmer when full.
- Timers for LED night lighting.
- Intermittent switching of water blowers to create an ebb & flow wave effect.
- Water temperature monitoring.
- Algae monitoring.
- Heater cycling to maintain temperature.
After getting involved with the parallax bs2, the idea hit me that this might be a super project for the Propeller. It could monitor all of these
conditions continuously and alert me when the aquarium needs attention. I am thinking a full scale project that would include an automatic feeder
designed to hold frozen food (maybe using Peltier devices to keep food frozen inside and add heat to aquarium on the other), multiple sensors and
probes to collect water quality data, light timing, automatic water make-up, and more. A large concern with this is that the probes I have looked into
for testing water quality are designed to only test a single parameter and cost around $300 to $800 depending on their specific purpose. The cheap tests
that I currently use are chemical tests performed outside the aquarium.
I was wondering or hoping some of the people on this forum might be able to help with figuring out how these probes work so I could put them together
myself. They are all small pen shaped devices that can't possibly cost that much to build.
This is only a first thought on a project I would like to get into one day.
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It's not the size of the dog in the fight, but the size of the fight in the dog.
- Weekly water parameter testing for pH, Nitrate, Nitrite, Ammonium, Salinity, Copper, Magnesium, Phosphates, Iodine and possibly others.
- Daily water make-up for the evaporation.
- Feeding of frozen foods twice daily.
- Timers for the intense lighting.
- Emptying the protein skimmer when full.
- Timers for LED night lighting.
- Intermittent switching of water blowers to create an ebb & flow wave effect.
- Water temperature monitoring.
- Algae monitoring.
- Heater cycling to maintain temperature.
After getting involved with the parallax bs2, the idea hit me that this might be a super project for the Propeller. It could monitor all of these
conditions continuously and alert me when the aquarium needs attention. I am thinking a full scale project that would include an automatic feeder
designed to hold frozen food (maybe using Peltier devices to keep food frozen inside and add heat to aquarium on the other), multiple sensors and
probes to collect water quality data, light timing, automatic water make-up, and more. A large concern with this is that the probes I have looked into
for testing water quality are designed to only test a single parameter and cost around $300 to $800 depending on their specific purpose. The cheap tests
that I currently use are chemical tests performed outside the aquarium.
I was wondering or hoping some of the people on this forum might be able to help with figuring out how these probes work so I could put them together
myself. They are all small pen shaped devices that can't possibly cost that much to build.
This is only a first thought on a project I would like to get into one day.
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It's not the size of the dog in the fight, but the size of the fight in the dog.
Comments
For sure you can get a probe to measure the PH. Not cheap, but available.
Salinity may be possible to measure using conductivity, which is simple enough.
Algae monitoring might be possible by measuring the reflectivity or absorption of some wavelength of IR, light or UV.
I am not aware of any probes for the rest, but if you can afford an ICP/MS all your monitoring problems would be solved.
Sounds like some pretty picky fish you got there.
Are you sure you don't want to get a dog? I mean for the price of a mass spectrometer, you could get yourself a whole lot of warm-blooded loyalty and affection.
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- Stephen
An aquarium monitor:
www.vernier.com/videos/play.html?video=50
An artificial creek:
www.vernier.com/innovate/innovativeuse27.html
Ion specific sensors are simple in principle, but in construction they require highly specialized materials. A thin specially treated glass forms the membrane of a battery, electrochemical cell, with a known solution on one side and the unknown on the other side. The electronics bring out the voltage of the battery, which is proportional to the logarithm of the concentration of one or several (interfering?) ions in the unknown. pH is the easiest and most common and usually the most important.
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Tracy Allen
www.emesystems.com
litmus paper? Just a thought on creating a much less expensive nitrate level detector. The litmus tests available are
not extremely accurate as far as the true ppm but, for a hobbyist aquarium, they would at least be able to show an
increase or decrease in the nitrate levels.
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It's not the size of the dog in the fight, but the size of the fight in the dog.
Actually for salt water fish, this is pretty typical. Even for serious fresh water fish breeding, most of this is required. Keeping fish is easy. Growing them, having a healthy environment, and breeding them is quite another thing. Also keep in mind that some salt water fish cost as much as a Purebred Golden Retriever, and a tank can "go bad" in a matter of hours under the wrong circumstances. I know of people who have a UPS (Uninterpretable Power Supply) on their fish tanks, but not their computers.
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John R.
Click here to see my Nomad Build Log
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John R.
Click here to see my Nomad Build Log
a very similar function, I just don't know what its actually called. The test strip turns darker shades of pink in proportion
to the ppm Nitrate. These are the hues I was looking at determining with a color sensor.
John R.: I have a sunk over $10k into my reef aquarium, the live rocks, live sand, filtration system, and the inhabitants. Most people
cannot believe it (nor could I when I got started in it). But, it has really turned out to be a great hobby for me. I love the
true challenge of it. The saltwater reef is absolutely beautiful but extremely difficult to maintain. Knocking on wood, I have not
yet crashed the system or lost any fish in 3 years; although, I have lost quite a few corals. Five to ten ppm nitrate rise is all it takes to
kill many finicky corals. Needless to say, at $100 to $300 each, losing one of these corals isn't much fun. This is one of the
reasons for a more constant monitoring of the nitrate levels in the water. All the other parameters I listed above need to be
monitored as well but they don't seem to constantly rise like the nitrate does. I believe this is a great application for the bs2.
I am already learning a lot in the process and am pleased to hear you have had some sort of success with the color sensor.
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It's not the size of the dog in the fight, but the size of the fight in the dog.
Who knows? Perhaps you'll be pioneering something here if you try to make something for the amateur/ semi-pro market.
Perhaps there is some way to isolate a large molecule (organic) liquid chemical indicator between a couple of membranes, membranes that allow nitrates to flow through but that will not allow the chemical indicator to flow out into the aquarium. As the nitrates pass through the membranes and into the chemical cell, the color changes. So long as this indicator is reversible, its color would indicate nitrate levels. You might poke around the patent literature and see if somebody long ago has already worked on something like that. It seems if you use a paper indicator and it's not reversible, then you'll have to scroll the paper through the sampled water somehow on a continuous basis. It would interesting to see if the paper is reversible, though, before going off the deep end: maybe a single strip could last you a week or so. Who knows?
patft.uspto.gov/netahtml/PTO/search-bool.html
Just a thought, anyway.
that would keep it from being widely accepted in the amateur arena. Going commercial would really require a great deal of repeatable
and provable accuracy in the tests as well as very durable hardware. Achieving the accuracy would entail a great knowledge base in
chemistry and biology that I don't have. However, I do believe there would be a demand for a truly automated system like this. Even
some of the most advanced sensors on the market still require human participation. It's really just a project for me to try and have fun
with while I am learning in the process. If any discoveries are made along the way then that would be great. I just want to see if I can
come up with some sort of working contraption for my own aquarium before I look to far ahead.
I did a little bit of researching on the patent site you posted. There are a few things out there but not a great deal of details that I feel I
could knowledgeably work with.
I have even thought of making a mechanical device that could automatically fill my test tubes with aquarium water, add the correct dosing
agents, and then use the color sensor to determine the levels by looking through the tubes at a controlled light source. I would then only have to
rinse and replace the tubes.
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It's not the size of the dog in the fight, but the size of the fight in the dog.
In addition, I've made the following observations/research:
All in all, this is all quite doable. Personally, I'm working with the Propeller, its far less expensive, and far more capable than the Stamp series. I'm also not convinced that Spin is any harder to deal with than Basic. There are also libraries that allow the use of basic, and even a couple of basic compilers coming online.
Personally, I'm in the process of setting up my water treatment room to convert the liquid rock that comes out of my faucets into usable water for fish. Once that's running a tad more automatic than it is now, I've got about 50 tanks waiting to get filled with water and fish. Most of them are 20 Gallon Highs, but there are a few 30 and 40 gallon tanks, a 75, 110, 150 and 200. Currently only the 75 and a couple 20s are running.
I've got the 75 running a live plant system with a commercial controller to monitor and control pH and Temperature. It also cycles the lights. pH is controlled by injected CO2, this is done for the sake of the plants. The angel fish (fresh water) are happy, and breed regularly. We've been less successful raising the fry.
The commercial unit I have is not the most expensive, but went for about $600 US with temperature and pH probes. These units do not scale at all to multiple tanks, and I have no intent of spending 600 per tank on 50 tanks. (Unless someone wants to donate the 30K). Long range, I'm looking at a combination of some automated testing as described above, along with some robotics or some other method to service multiple tanks.
One step at a time, pH and temperature are first on the agenda.
One other thought I had was looking at some of the "multi-strips". These strips have multiple pads to test a number of parameters with one strip. They are not terribly accurate, but could be used for "screening", and if a value was out of norm, or changing on a specific tank, further testing could be done. With the multi-strip, you could get the stip dipped, and have it "automagically" be indexed in front of the color sensor to read the color/value of each pad.
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John R.
Click here to see my Nomad Build Log
If done with the right style, a system like that could actually add to the visual theater of your aquarium. How about something in the style of the old Jules Verne movies, like 20,000 Leagues Under the Sea?
"Captain Nemo, stand aside, now it's time for me to demonstrate that other miracle I excavated from the drowned rubble of Atlantis: the automatic nitrate titration machine..."
I would envision using very small tubing, not unlike the stuff you see IVs dripping with. This could give a very fine resolution to the amount of fluids dispensed.
There are also small pump heads available, in the 2 to 3 inch OD range. These things are capable of dispensing drops.
Syringes can work, but are more challenging to "reload".
The advantage of peristaltic pumps is that if you can measure/control the rotation, you can know with some certainty how much liquid was dispensed. The same is true for syringes.
Ultimately, there may be both syringes and peristaltic pumps. Small bore syringes could work well for reagents for testing. I could then see using a peristaltic to feed appropriate doses of premixed solutions to correct any problems.
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John R.
Click here to see my Nomad Build Log
Still thinking out loud...how about a movie projector type situation where you would use the same media as is used in the dip testing strips only they would be placed single file on a small reel that could be used like a reel to reel device that first passes under a dripper and then goes in front of the sensor to be tested. Then it would continue on to the take-up reel for safe non-contaminating disposal. I am quite sure these color changing reactants can be more accurately detected by a sensor than the human eye. It just requires calibrating. The whole color matching process can be a little difficult at times with the palette cards they give you.
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It's not the size of the dog in the fight, but the size of the fight in the dog.
www.umd.umich.edu/casl/natsci/slc/slconline/MICRPIP/index.html
The tank water is deposited on the test strips by another set of drop dispensers that are fed from the tank water siphons through a single solenoid. These drop dispensers may require drop counters to ensure reliable operation but it will probably not be necessary.
If the test strips are available in rolls then individual rolls could be used for testing. If rolls are not available it might be possible to mount the test strips on a carrier roll such as a calculator print roll or adhesive tape. With careful spacing between the optical sensors for reading the test strips and the drop dispensers it should be possible to position the test strips for dispensing and reading using only the test strip reading sensors.
The procedure for taking a measurement would be:
- Stop the tank water return pump so the float valve can close and pressurize the tank siphon tube.
- Move the test strips under the drop dispenser.
- Open the water test supply solenoid and wait for a delay period or for all drop sensors to report a drop.
- Wait for whatever period is required for the reaction to take place on the test strip.
- Move the test strip under the optical sensor and take measurements.
I like your diagram kwinn, I would imagine it looking something like that as well. The Reagent Reservoirs would have to be to the side of the tank so any mishaps wouldn't contaminate the tank water.
I tried to make a drawing of the delivery method I was considering.
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It's not the size of the dog in the fight, but the size of the fight in the dog.
Your water tester picture is pretty much the same as what I had in mind. If you could get one long strip for each of the tests they could be mounted side by side, fed by one common mechanism, and processed in parallel.
If you had to fabricate your own strip roll my initial thought was to fabricate it in parallel as well but on further consideration it might be better to mount the strips sequentially. That way you would only need one drop dispenser and optical sensor to read the strip. I doubt you will be taking measurements often enough for the extra time to matter and the chemical reaction needs some time to take place as well.
The concern would be that a few drops of water may become saturated with the test reagents, and give a false reading.
Also keep in mind that you'll need a way to flush the line feeding to the test strips, as you want to get water from the tank, not the water that's been sitting in the tubing since the last test.
My thoughts for a peristaltic pump or syringe based system are targeted for a muti-aquarium environment.
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John R.
Click here to see my Nomad Build Log
I have some test strips and I ordered a color sensor yesterday, so I will run some initial experiments to see what comes next on this project.
A drawback that I am already seeing with the test strips and my spooling idea is the resident moisture and humidity involved within such close proximity to the water in the tank. The test pads will become useless if moisture gets to them in advance of testing. ~ More food for thought...
In your case John, thinking commercially, I suppose cost isn't as large an issue when consideration is given to how many aquariums a single testing unit can handle. I think then, I would definitely go the chemical analysis route. I would also recommend a setup like I've got shown in my drawing below. It sure would simplify many water issues for you. Have a look and let me know what you think?
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It's not the size of the dog in the fight, but the size of the fight in the dog.
Possible to make an ion selective probe at home? I guess... if you happen to have some ion permeable membrane laying around... ;P
Seriously, I was wondering if you had made progress in an aquarium controller, or had lost interest?
I had completely forgotten about this thread, but with it's resurrection I am wondering if it is possible to do this with a simplified form of Atomic Absorption using the linescan imager, a prism and a small light bulb. I guess it would depend on the wavelengths absorbed by the chemicals to be analyzed and the sensitivity of the linescan imager at those wavelengths.