Automated aquarium chemical dispenser is extremely precise


[Robovergne] prides himself on the beautiful reef aquarium that he has set up in his home. These sorts of water displays require constant maintenance due to the mineral requirements of living coral. Rather than add mineral solutions manually, he decided to build a nano-doser using espresso machine pumps (Google Translation).

These vibration pumps run on mains voltage, so he had several options as far as how to control them. Using relays would likely make things pretty noisy, so he chose to use a zero crossing detection circuit to precisely control the pumps’ duty cycles and output.

His setup uses a PIC to control everything from the zero crossing circuit to the display LCD. An amount of product and the distribution time frame are entered using a handful of buttons mounted on the front of his control box, leaving the PIC to do the heavy lifting. It will calculate the proper length of time to run the pump based on several factors, including fluid viscosity and height of release.

It really is an impressive system, and while his needs are very precise, we imagine this sort of setup would be quite useful in building less complicated dispensers, such as those found in an automated bar.

Continue reading to see a few videos of his Nano-doser in action.


17 thoughts on “Automated aquarium chemical dispenser is extremely precise

  1. Peristaltic pumps are great for moving/metering/dispensing liquids, but not so great for chemicals.
    The down side is the tubing can be dissolved by some, or leech plasticizers into the liquid. Just be sure that they’re compatible to be safe!

    1. Thats not a peristaltic pump though, its a vibration pump. Also peristaltic pumps are used with tubing that has high chemical resistance.

      I am very impressed with the overall execution and solutions to the design challenges faced in this project.

  2. Pretty cool, and I can think of a ton of uses for a similar setup ranging from urban farming to certain types of bio and chem lab work. Hey, could even use a variant of this to dispense dyes or food colorings to precisely match a desired color, or supply nutrients to that live brain in a jar every mad scientist has to keep around per union regs….

  3. “The down side is the tubing can be dissolved by some, or leech plasticizers into the liquid.”

    Use a platinum cured silicone tubing – should be fine for most things. That or norprene. Platinum (not condensation) cured silicone tubing is used in high end medical applications so leeching concerns should be moot.

  4. I would like to see someone put one of these a washing machine. You could have it put in set amounts of bleach, fabric soft, and detergent.

    Throw in your clothes and have a button for whites that does bleach, detergent, and whatever.

    Normal clothes would have just the detergent.

  5. I have heard that maintaining the correct values of minerals in an aquarium is very hard. You have to measure many values and adjust them by adding minerals or water.

    With measurement tools integrated the whole control loop could be automatized. That would be the ultimate tool.

    1. On small tanks, yes. It can be tougher since water evaporation can make a huge impact in all sorts of parameters. I had a 120 gallon reef tank with another 30 gallons in the sump. With a calcium reactor I never had to worry about adding any chemicals. A calcium reactor uses a tiny amount of CO2 to slowly dissolve crushed coral in a reactor. This is added to the tank water and supplies all the minerals needed.

  6. I haven’t come across any in that range, but yes that would certainly make it seem suddenly very interesting to me. Anyone who has links to a well priced good supplier, go ahead and add linkage :)

  7. In fact that makes it the go to choice of all manner of kitchen machines. Drink mixing etc. I’ll have to get my hands on one to see if it could handle something with thick viscosity such as pancake batter.

  8. Awesome, I wish the original article was in english. Damn my limited language skills!

    Very well put together nevertheless, I could definitely find a home for something like this in my shop.

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