Help me build a safer kalk ATO.

Discussion in 'Equipment' started by anathema, Nov 9, 2011.

  1. anathema

    anathema Supporting Member

    I appreciated the suggestions in my thread about buying a tank controller, but I wanted to make this it's own thread. In light of recent events, I've been reviewing my ATO setup and making significant changes. First, I've switched from a 50G reservoir to a 15G one, so the risk is much lower. I'll have to figure something out for next summer while I am in Alaska again, but until then it makes no sense to run the risk of such a disaster.

    In addition, I've bought a Reef Angel controller, and it is currently running a simple ATO with the help of a slightly modified ATO script Roberto was kind enough to write for me. However, I've been running over the options in my head and I want to build it to be as dependable as I can.

    The goals are as follows:

    1. Perform ATO function with the lowest possibility for the system to overdose Kalk.
    2. Shut down ATO if PH rises too high.
    3. Shut down the ATO, heater & skimmer if the sump gets low.
    4. Shut down the ATO pump if the RA relay sticks on.
    5. Notify me if the system is out of spec.

    So here's the plan I've come up with:

    3 Float switches:
    #1 float switch controlling the ATO, with a timeout set. If the timeout is exceeded, ATO is deactivated and notification is sent to me.

    #2 float switch providing the low sump sensor, which when activated shuts down heater, skimmer, ATO, and sends a notification. (Currently this isn't how I have it, but I need to learn this scripting language to change it hah!)

    #3 float switch, a basic single switch relay from plugged in between the RA and the pump, which provides a safety on the system running away for any reason, stuck relay, me getting stupid with the scripting, me leaving the RA stuck in a menu while I dreamily stare at fish with the ATO active, etc...

    In addition, if the PH rises above let's say, 8.6ish(?), then the ATO would deactivate. I haven't figured out for sure if I can do this with the RA, but I don't see why not. I am undecided if this should be a "fault" disable which disables the ATO until serviced, and sends a notification. It depends on how often this type of event occurs, and since I've never really chased my PH numbers I'm not sure how much the fluctuate normally. Open to suggestions on this. If it's not a fault notification, I run the risk of it falling into a loop and still being able to overdose, although much more slowly. However, having the ATO shut down while I'm away is a serious problem too. The system needs to be robust enough that I can still go to work...

    I'm leaning towards making this a temporary state, and if the PH is above a certain point it will simply refuse to run the ATO, but not throw a fault and disable it, my hope is that the timeout would catch any more serious conditions that occur.

    Any input while I'm in the planning stages is appreciated. If I'm headed the wrong way I'd rather know now than after I get it half put together.
  2. rygh

    rygh Supporting Member

    I think you need a fundamental change: You cannot use Kalk as part of your ATO if you want real safety.

    What you need to do is put Kalk on a timer, much like you would dose 2-part.
    So every few hours, you dose a bit of Kalk.

    Measure the minimum daily normal top-off water, and set your Kalk doser
    to pump in a bit less than that amount every day.

    Then on the side, you have a normal ATO, with pure RODI, to make up for what the Kalk does not do.

    A bonus is that you will have a more constant addition of Kalk. It will not go up/down
    as your evaporation rate changes.
  3. Coral reefer

    Coral reefer President

    Sounds good to me
  4. After having a pretty devastating Kalk OD last year I wanted to build a fool proof system and I think I have. Its a very simple solution all though a little expensive. I use a ATO switch from connected to a peristaltic doser (you must use the large diameter line) then through the Kalk reactor. This has worked well for me I even had a float switch malfunction while at work with no problems the doser pumps enough to keep the water level where it should be but could not even if on always pump enough into the system fast enough to cause an overdose. IMO this solution has proven itself fool proof.
  5. GreshamH

    GreshamH Guest

    ^^^ is how I have run my Kalk reactor for ever (5+ yeras now), never had a kalk issue.
  6. GreshamH

    GreshamH Guest

    Probably best not to state stuff as a fact, especially when you are not right :) You can have kalk be a safe part of system, you just have to DESIGN it right. Mine is safe. My dose rate can never dump too much kalk into my tank. It constantly drips and rarely turns off. It never clogs. The only thing that needs to be done is once every few years I need to move the peri tubing a little and every month replace my kalk.
  7. scuba71

    scuba71 Supporting Member

    Out of curiosity, how do you have yours set up Gresham? Do you have a doser pump on most of the time?
  8. houser

    houser Past President

    I have Gresham's on steroids.

    Ultrasonic transducer output fed into PID loop, PWM output to 12VDC welco peristaltic pump. Accurate to less than a mm.
    If sensor goes out, PWM rate can't go above a certain duty cycle, effectively limiting dose rate.
    Float switch for double safety. pH interlocks.
    Pharmed tubing for ultra ultra long life.

    Not saying you need it, but that's the DESIGN G was talking about.
  9. GreshamH

    GreshamH Guest

    Just like Guywalker...

    I have a reservoir for my RODI which is pulled through my kalk reactor using a peristaltic pump. It's activated by a float switch. However, I have the speed on my peristaltic tuned just right so it's pretty much always dosing. It turns off every once in a while, but rarely. I move a TON of air across my water so I have a lot of evap. I also do not have my reservoir on a float valve or switch. I used to at my old place, but now that I am at a large facility, I pull from a massive res. connected to a few others. One fill exhausts our filters/smaller DI/carbon so its fill & replace. We use massive DI canisters after the DI in the RODI. Those only get replaced once a year. Someone is in charge of keeping those filled :)

    I do not use hobby grade peristaltics, but not everyone has access to equipment like Dave and I... freaking jealous of Dave's set-up :) I bit the bullet and bought used lab equipment years ago and never looked back.
  10. GreshamH

    GreshamH Guest

    Which Welco? Brushless? :D Awesome units. Not quite "lab" grade, but commercial none the less. Can you get my brushless one working :D

    With all the gear I have I could put something together like yours, but I'd have to get someone from Siemens to program the damn thing :( I lost my contact a while back and the programs I had designed I doubt would work. It's was mainly designed to raise and lower my light canopy through out the day, as well in case of heat issues. It also would raise and lower some doors allowing more airflow, and kick my inline fan into the higher speed. PSSH now APEX and Reef Angels could probably handle all that and probably much easier to program and deal with.
  11. houser

    houser Past President

    Brushed. It is relatively loud though and honestly if it wasn't in the garage I doubt I'd use it. NEGATIVE WAF.

    I have all the automation gear - so it was easy and fun. I'm a gear junkie.

    But back to OP - this seems like something the RA community could help with, no? I'm not familiar with the support scheme, but I got to believe there are pre-canned routines for your very situation.

    Software aside you could certainly do this with a slow (metered) pump, a low level float switch, and a shutoff switch. Adding programming makes it more robust. Ultimately you cover all the bases. Seems that's where you are going - wish I could help more just don't know the RA.
  12. rygh

    rygh Supporting Member

    Gresham : Please note that my first two words were "I think", but yes, I worded it to too strongly.
    (I was more interested in describing an alternative)

    However, I still feel that kalk on an ATO is generally a risky setup. This is why:

    1) The big risk in my mind is getting a leak when you are gone for a few days.
    That is the failure mode where chemicals connected to an ATO have fundamental design risk issues,
    and are not just a matter of better components.

    2) Your evaporation rate changes.
    Depending on where you live, potentially by a lot.
    That means there is a fair bit of uncertainty in setting that critical maximum dose rate, and
    to make sure your tank does not empty, you have to set that dose rate a bit higher.

    3) Setting and guaranteeing that max-dose rate is critical.
    If you measure carefully, and have a high quality peristaltic pump, then you are probably fine.
    If you have a cheap valve on a drip line, and guess by looking at the drips,
    then you likely have a high risk problem.

    4) There is a high reliance on fancy equipment
    The simple float switch connected to a relay is definitely risky. (I can state that as fact)
    So you have to go with fancy transducers and things like that.
    But those bring their own set of concerns due to complexity, and they are often not
    tested by manufacturer in a salt-air environment. Plus are expensive,
    beyond the average hobbyist.

    5) Backup features are important and they can be difficult to build and test.
    Sure, Houser's ultimate system almost certainly solves the problem, and I would guess he did it right.
    Can everyone do that? If you don't, then the risk goes up.

    Yes, it is solvable through design.
    But can an average hobbyist on a reasonable budget can set up a reasonably safe system?
  13. houser

    houser Past President

    With a peri you won't have the head height issue at least.

    I actually think you have a pretty good grip on what you want to do. You have software doing most of the work with a hardware failsafe. I think you can plan around having to "disable" the ATO with a little more work. Again I don't know the RA but I would think it's got what you want, and others have already done it. Benefit of "open source".

    when you decide on your hardware list put it up and we can figure out the best logic. Most of the time the logic changes based on what you have on the table. Seems lots use peripumps off eBay - Cole parmer rebuilds, etc... Start there. Since you are out on the road (or seas) a lot I think you're wise to make this a good one.
  14. anathema

    anathema Supporting Member

    Thank you everyone for the input, this is exactly why I posted before I started buying pieces.

    RYGH I respect your opinion and appreciate your thoughts also, however I did try to make it pretty clear in my thread title I'd already chosen to ATO with Kalk. :) I have a somewhat unique reef keeping methodology, and I like the results I get from it. For better or worse, kalk ATO is one of the major parts of it and changing that changes many other things. (I might even have to start using RO water! :X ) I know how you feel though, I feel the same way about calcium reactors and to some extent skimmers. Basically our tanks can explode at any time and if we think we've got it all sorted out we can still be surprised. :(

    As for the doser idea: Genius. I can't believe I didn't think of setting it up like this earlier. A peristaltic pump makes perfect sense. I guess the easiest thing to do is either buy the Bubble Magus expansion box or the dosers for my RA. Neither of those seem robust enough to run almost full time though, at a glance. If anyone has a link to a pump I could use that's rated for continuous duty I'd appreciate it. Or also if I'm under rating the Bubble Magus doser that info would be nice too. I guess I also need to figure out if the dosers for the RA can be triggered by the AutoTopOff function, because if I use the BM I can't use a float switch. Hmm, I'd much prefer to have it integrated into the RA setup instead of having it all splintered into separate systems. This will take some research I guess. H)

    Here is the RA doser, if this can be triggered through the AutoTopOff function in the RA it might be the best choice. (preliminary skimming says it would work, from my understanding in my sleepy state tonight I think these are simply controlled by toggling power to the plug, not a separate input from the RA.)

    Do any of you find you need to run two dosers to keep up? I am not sure I like the idea of a doser running all day for the noise, either, My bubble magus is a pretty annoying sounding device, but it only comes on for a few seconds at a time so it's usually not a big deal. Any ideas for solving this? Build a dynamat box? :p

    Gresham what do you mean by "the larger tubing"? Do you simply mean the normal size airline tubing not the thinner stuff that is usually used with dosers? Or is there something I specifically need to purchase to make it work? I assume this is due to clogging issues, do you have to swap in bigger tubing through the pump head also? I don't generally stir my kalk, so it's usually pretty clear with no particulates in it, I'm hoping I'd be ok to use something like the RA doser.

    Sadly, I kind of tried to set things up with lower flow in the beginning when I set the tank up initially. I used the smallest pump I could find that would pump water to the overflow. Unfortunately when the barrel got half empty it couldn't pump the water that high anymore so before I went to AK last summer I swapped in a MJ900 I had laying around to make sure it used the full barrel. If I'd swapped back... Yeah anyway. :tired:

    Well off to bed. 3AM comes early and I have to move the derrick that's building the new exploratorium tomorrow.
  15. anathema

    anathema Supporting Member

    Oops caught me mid edit. I think I have a plan forming, I put in a link to the RA doser and I think that might work.

    For tonight I need to get myself to bed or else I'll fall asleep mid barge move and put a hole in the Embarcadero or something.

    Got... to... stop... reefing... and... sleep... ZzzzZzz.
  16. iani

    iani Guest

    Keep in mind some of the digital cole parmers (like the one I have) will reset when the power goes out. If you want to keep it on a float switch I would consider a unit with manual control.
  17. rygh

    rygh Supporting Member

    Sorry, did not mean to hijack your thread, I was more responding to a post that well... questioned why I had concerns.

    Going with a reef angel and a peristaltic pump sounds like a good plan.
    I run that exact setup for my standard ATO. It runs for less than a minute, every hour.
    I have a standard BRS dosing pump, on a 220G tank, and flow has not been an issue.
    Might be a bit fast for Kalk, but then you could dose every 15 minutes, and really spread it out.
    Flow was a problem with my old Drew's Dosers.

    The reef angel default ATO code is pretty basic though, so you might want to tweak it.
    At the very least, put a limit on the total time dosed per day, as opposed of per dose.
    If you want to get fancy, you can make it adaptive.
    Accumulate the total time dosed for a day.
    Make the maximum dose time be the previous day * 1.2 or so.
    If it hits that maximum, trigger the buzzer.
    The only tricky part is to reset it if you do a water change.

    As a side note, I have been tinkering with a different way to measure water height.
  18. GreshamH

    GreshamH Guest

    If you are not running your RODI into a res and feeding the Nilsen Reacter straight off the RODI, you do not want it coming on a ton. Its best to either do a few longer runs, or constant. Pushing your RODI to turn on a bunch will not only burn your DI filters, it will constantly dump not so OK water at start-up IIRC.
  19. GreshamH

    GreshamH Guest

    I like getting the raw drivers myself, or units with just manual speed control.
  20. newhobby

    newhobby Guest

    RA dosers won't work for this purpose. It uses brushed motor that won't last long in this situation.
    They are not designed to be running on continuous mode like you are planning to.
    Bubble magus is the same thing.
    You should consider a higher grade with brushless motor or stepper motor.
    I have a welco pump that never gave me problems either. Very noisy though. Worse than Bubble Magus.
    Use a decent quality tubing too. Otherwise you will be replacing them constantly.
    RA could be used to start and stop the pump based on pH reading too, like your thought on the original post.
    So, you could disable the ATO temporarily if pH rises above threshold.

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