Automated Salt Dispenser Interest/Existance?

seriously right?!

 

Yes this is true but that's where a semi-auto option could be interesting. Meaning, everything is done automatically up to the point where you check the salinity yourself and say ok... press button whalla wc starts and done. Though that's where the salinity monitoring comes in over a day or two to ensure it's accurate and stable. If any question at all then simply stop the process in the code. (Computers don't make mistakes, people do.)

Well lets be honest with ourselves here, if cost and time savings mattered to us that much then none of us would be using controllers... All controllers do is automate things for us at a huge cost in terms of dollars. It's just a question of how far you go with it. As was mentioned in another post, this type of measuring/mixing is done every day in the industrial world so in my mind there's nothing to stop us from doing it besides our budgets and imagination.

 

Ok so since there does seem to be some interest let me spill out the best i can the pictures swirling around my head... oh how i wish i was an artist says the stick figure master... anyhow

I really think this could all be done fairly afford-ably.
I would first try an auger style dispenser to see if at very slow speeds for set intervals i could get it to dispense consistently. If not, then i would somehow incorporate the weight option.

I'm going to assume that i could skip the weight option for now as i'm brainstorming mainly on the mechanics of this and that could simply be added later if needed.

Found this auger online

it has aproximately a 2" diameter and an overall length of 6 3/4"
It's only $17 + 6 shipping...

You would also need a motor to drive this thing, i'm honestly not sure off the top of my head what the best option would be here... It would need to have a little bit of torque to handle the weight of the salt pressing down on it but be capable of turning very slowly to allow for accuracy.

The tricky part would be building an enclosure for this to sit in. What might work is if this slid into a tube of some kind fairly snug (hopefully PVC, DIYers best friend) and then build some kind of hopper over top of it to funnel the salt down to the tube... cut out an entrance on the top of the tube on one side and then an exit on the bottom on the otherside... hook up a motor and all the necessary electronics be they to a controller or just a set of switches/timers and viola. Ideally, i would build this hopper/auger unit in a way that i could attach it to the top of my favorite 5 gallon salt mix. That way all i have to do is snap it on a new bucket of salt, flip it over, and plug it in. What ever method used to hold the salt it would have to be well sealed or moisture would get in and turn the salt hard which would constrict the flow into the unit.

Does acrylic and PVC fuse together? Perhaps the hopper could be built out of that which would give the added benefit of allowing you to see at a glance when you're low.

From a DIY (automation) standpoint i really don't think this would cost much... The sensors and controller is where things start getting pricy but for those who already have a controller, especially a DIY one that you can do well anything with... then this wouldn't take much extra and they're already spending pretty pennies on stuff like this...

Maybe i'll throw some scratches together and see if it comes out looking anywhere remotely close to what i have locked in my head. No guarantees though...

 

Standbye for my highly technical drawings!


It occurred to me after drawing this that maybe I should just find and modify an old meat grinder...

 

That auger is going to need a gear on the end driven by a worm gear for sure.

Start building!

 

Huh, interesting. Unfortunately I was more dreaming and or planting an idea in someone else's head, at least for now. My current build is probably going to be an algae scrubber. Problem is I'm self employed and no body likes to pay their bills on time so... kinda broke atm. Some day though. Seriously though, Thanks for the idea of a worm drive! Would be perfect for this setup.

 

Not a crazy idea, but i don't think it worth the effort, simply for adding salt to the mixing container, but a few things that come to my head that you need to figure it out.

1. You need to keep salt in humidity free container and avoid any humidity from entering the salt container.

2. Salinity can be tricky to measure given that you're mixing it, so it will slowly raise while it is mixing and maybe your salt dispenser will dump a second low before the first one is completely mixed, and that can lead to salinity spike.

3. Use containers for the size of the water change, this way you don't store mixed salt for to long.

4. maybe a modified autofeeder can work to dispense the salt.

IMHO make the water change system but keep the salinity control to yourself, to many things can go wrong with this that can hurt your tank.

 

Sorry if any of that sounded like a rant.

 

I've posted about this on a few other forums (nano-reef.com and RC) and gotten very little interest. In any event, my solution was to store the salt in a salt slurry reservoir - 24 gallons of salt water at 40-45ppt salt or even higher. The idea being to dodge the humidity problem...

For you see, no matter what dispenser you build, you will have to at some point transfer salt from your bucket into the dispenser. Since we don't have robots to drive to the store and get the buckets and put it into a dispenser, I accept that I will have to do that much ... but any dispenser in my basement will be subject to excess humidity from the topoff container, the RO/DI system, the occasional mistake/overflow, etc. So I figured why not just store the unused salt in water itself? Getting 24 gallons to say 60ppt would need about 15 cups of salt, and I'm willing to put salt into the reservoir once a week, so I imagine I can keep up with it. Then a standard pump on a controller can load the salty water either directly into the tank or into a mixing/heating container; another pump from the ATO reservoir can adjust the mixture to 35ppt.

In my case, I am just at the point where I have continuous temp monitoring for my tank, ATO, and ATO for the salt slurry reservoir, so I have work to do yet to get the mixing / water change done. But from where I am it's a "mere matter of programming" as all the core stuff for the automation is in place - a 12 socket power bar with each socket that's arduino controlled to power all programmed equipment; sensors for temp, salinity, and pH that I've tested with the Arduino, and an internal website for displaying the metrics (at this point only temperature) and sending me alerts. So hopefully I'll finish building the tank automation in the next few months.

Osric

 

Cool, I can see where a salt slurry would be beneficial to this application. Would certainly make it easier to transfer the salt for sure. Guess my only question would be how consistent can you get the mix to be. As for the transportation of salt that's why I thought it would be cool to design something that you could simply snap onto a fresh bucket of salt and then flip the whole thing over and slide it back into a Mount. Definitely understand everyone's trepidations about automating this process but in all honesty it would be no more dangerous than automating anything else. If one single part of an automation system fails which controls anything added to a tank, then you would have a problem to varying degrees of severity. At least what we're talking about here is adding something to a mixing tank and not into the primary flow of a system. That factor alone makes an automated salt mixing station inherently safer than even a simple ATO as there is an opportunity to insert a checks and balances system into the design. If I ever win the lottery I'll definitely build one of these suckers.

Will hopefully start a diy reef controller soon which will of course bring all of this one big step closer...