Automated Salt Dispenser Interest/Existance?

Discussion in 'I made this!' started by epsilon, Jan 10, 2013.

to remove this notice and enjoy 3reef content with less ads. 3reef membership is free.

  1. epsilon

    epsilon Feather Star

    Joined:
    Aug 3, 2009
    Messages:
    752
    Location:
    Toledo, OH
    Hey guys,

    Been reading a pretty cool DIY reef controller thread on another forum and it's gotten me thinking about waterchanges recently. To my surprise there didn't seem to be a lot of interest in automating this portion of tank maintenance there and one primary feature of automated wc in my mind would be the salt mixing. After looking around i haven't really found any plans for a salt dispenser. Closest i found was a youtube vid with what appeared to be an auger poked through it. Was wondering what thoughts you guys had on this? Here are mine.

    1. Doesn't have to be fully automated but easily could be incorporated into a DIY controller.
    2. Salt output would be precipitated by a screw/auger style motion. I think this would give us the most control over the amount coming out and still be economical.
    3. Hopefully volume could be calculated to within a decent +/- accuracy by simply timing how long the motor would run. If results turn out to be to inconsistent then i'd propose first dispensing onto a scale of some type and measuring it out by weight.
    4. In a semi automated setup, after the salt is dispensed and mixed, testing would be required by hand to ensure the salinity is correct. Not sure about you but i just wouldn't trust any setup with something this important! In a fully automated system the water would not be utilized until a reading was taken from a conductivity probe and found to be within the expected range. I would also setup the automated wc to occur during a time of day that i am typically home so i can 1 keep an eye on it and 2 be close by if an alarm is triggered.
    5. Frequency. Been reading a little on this recently and i know a lot of automated wc systems tend to lean towards either a continuous exchange or 1-2% of volume per day. I tend to be of the thinking that larger less frequent changes are both more economical and of greater efficiency. If i were to set this up fully automated i'd work off of a time scale like this. Wednesday - Mixing reservoir filled to preset level. Salt is dispensed, heater turned on, mixing commences.
    Thursday - Temp/PH/Salinity readings are tested. If salinity is too high then an alarm is sounded to notify me and the systems automated dispencing would be canceled and need reset. If it was too low, i'd still get an alarm but it would simply add a small amount at a time, continue to mix, and test until the range falls within the specified range.
    Saturday - WC occurs, email report sent with DT temp/ph/salinity readings as well as new water temp/ph/salinity settings and if there were any problems with the weeks mix (i.e. multiple attempts to get the salinity correct.)


    Out of time for now but these are my thoughts on the subject... Just curious if there is any interest out there. I am also of the mindset that this is an important aspect of reef keeping and that certain checks/balances should be implemented before trusting it. Which is why the only way this should ever be used with full autonomy is with all the checks/balances/alarms in place and functioning. Bet even a partial automation of this task for me at least would be welcome. If all i had to do for a wc is test the new water and open/close a couple valves ect i'd be happy.
     
  2. Click Here!

  3. m2434

    m2434 Giant Squid

    Joined:
    Jan 11, 2011
    Messages:
    3,471
    No interest here, automated water changes yes, mixing no. To many potential pitfalls and relatively slight changes in salinity can be catastrophic.
     
  4. FatBastad

    FatBastad Zoanthid

    Joined:
    Feb 28, 2012
    Messages:
    1,133
    Location:
    MA
    That would be pretty cool.

    Some folks have built auto water change systems but I assumed the salt addition part was still manual.

    If the rest of the process was automated and just the additon of the salt was manual, that would still be sweet.
     
  5. barbianj

    barbianj Hammer Head Shark

    Joined:
    Sep 27, 2009
    Messages:
    2,634
    Location:
    Port Washington, WI
    I'm with m2434 here. The act of adding salt to a container takes very little time. The cost of automating that aspect versus the payback would be a very low priority, IMO.

    I would think that accurately weighting the salt for a given water volume would give you a more accurate mix than using an auger, unless you have a huge tank. Getting the reading right is what takes time.
     
  6. Thatgrimguy

    Thatgrimguy Flying Squid

    Joined:
    May 15, 2011
    Messages:
    3,026
    Location:
    North Biloxi, MS
    Automating the water change it's self is wonderful. Been doing it for over a year. But as far as mixing. I want the control that doing it manually provides. M2434 nailed it as usual.
     
  7. Servillius

    Servillius Montipora Digitata

    Joined:
    Feb 7, 2011
    Messages:
    1,062
    Location:
    Houston, Texas.
    Since salinity can be measured by conductivity, it should be possible to automate the process and include reliable failsafes (two conductors and an auto-shutoff if they're not within X% of each other).

    You would need:

    1. A reaction vessel. That's easy.
    2. Salinity probes and a controller. Cost money, but shouldnt be hard to find.
    3. Some method for adding salt slowly. There are a variety of industrial components that do this.
    4. A way to make sure there are no dead spots in the reaction vessel (actually not critical if you're measuring salinity continuously, but things will go pear shaped if salt piles up in the corners).

    Frankly, this looks like a simple engineering problem to me. Quite doable. In industrial applications, we always think its safer to do these things by hand when frankly, properly set up automation is much safer.

    Who's the first equipment manufacturer to run with it?
     
  8. Click Here!

  9. barbianj

    barbianj Hammer Head Shark

    Joined:
    Sep 27, 2009
    Messages:
    2,634
    Location:
    Port Washington, WI
    Salinity probes are relatively inexpensive. This one is only $75. Reef Angel Controller

    Absolutely agree with you about industrial automation. All of the components for doing an at home auto wc system are there, but nobody that I know of is doing it. Probably because it's your own reef tank that would suffer the consequences while you are getting the bugs out.

    What's that saying, laziness is the mother of invention?, lol. I could see how for some people it would be worth the effort.
     
    1 person likes this.
  10. FatBastad

    FatBastad Zoanthid

    Joined:
    Feb 28, 2012
    Messages:
    1,133
    Location:
    MA
    I love being lazy, I dig this concept haha
     
  11. m2434

    m2434 Giant Squid

    Joined:
    Jan 11, 2011
    Messages:
    3,471
    In college, I helped maintain a zebrafish facility, with automatic mixing and water changes. It had tens if not hundreds of thousands of dollars in monitoring equipment, and controllers, autodialers to page us if something went wrong etc... The home controllers, such as the Apex are getting better, but still no where near the quality and reliability of the industrial stuff, but also no-where near the cost.

    At home, my system is simple. I feed RO/DI into a brute trash can, next to it is another brute, with a marked water level line for saltwater. I have a pump and transfer water to the salt container and a per-marked container for salt and a 4' pvc pipe to mix, there is a heater and a refractometer on a shelf next to it. If I need saltwater, I plug in the transfer pump, until the container is full, fill the salt container to the line and dump in, mix with the 4' pvc pipe and plug in the heater. Once the green light on the heater comes on, double check with the refractometer and it is ready for use. If a new batch of salt, I test ca, alk etc... Very sophisticated and expensive setup though LOL but only takes about a minute or two to fill and mix so worth every penny IMO!

    Now, if the system could automatically monitor ca, alk, mg and salinity etc... have the same reliability and be cost competitive, I would consider it ;)
     
  12. Servillius

    Servillius Montipora Digitata

    Joined:
    Feb 7, 2011
    Messages:
    1,062
    Location:
    Houston, Texas.
    I would give my left... well, something valuable for a live continuous alkalinity monitoring method.