Direct RODI - Kalk ATO

I only clean it out once a year or so. I keep the intake for the dosing pump about 6 inches off the bottom. Limewater is self purifying , you just need to let stuff settle. I add more lime at each fill up. I leave the residue in the bottom, until I'm ready to clean. As long as you aren't sucking up residue there is no issue. Most everything settles over night. I've never had an issue in over 5 years. I know there's a long thread on RC about it by Randy in the chemistry section.

Sounds like you have a great setup.


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You can also try using timers to dose kalk and use your PH probe as a safety.. I tried this method with my RKL.. Plus I had a 2nd A TO with RODI in case my level reached 8.4, I still kept salinity stable.
 
You can also try using timers to dose kalk and use your PH probe as a safety.. I tried this method with my RKL.. Plus I had a 2nd A TO with RODI in case my level reached 8.4, I still kept salinity stable.
Thanks for the advise, are you using Apex for your timers? You hit the nail on the head from my vantage, that exactly what the system does, it uses the OSC function changed a little from the diagram) currently 40 seconds ON every 15 minutes, the pH in normal increments is used to turn on Kalk or RODI solenoids, but, if pH hits 8.4 the Apex drops power to the Smart ATO. The theory is 40 seconds every 15 minutes, at 3 PSI (system is in the basement, so this is just slightly faster than a drip) with full Kalk solution, should not exceed pH of 8.5 even if smart ATO fails, I have tested this a few times, by, bypassing the Smart ATO solenoid.
 
Also look into ro solenoid valves!!! Hope that helps to cut water being feed to the unit or whatever


Are you saying additional solenoid valves? There are currently three in place now, one on the Smart ATO, one on the direct RODI feed and one on the Kalk feed. All pretty much set to shut off, if anything is amiss, pH > 8.4, salinity < 34.8, float switch closed, too much time on (Smart ATO).
 
Are you saying additional solenoid valves? There are currently three in place now, one on the Smart ATO, one on the direct RODI feed and one on the Kalk feed. All pretty much set to shut off, if anything is amiss, pH > 8.4, salinity < 34.8, float switch closed, too much time on (Smart ATO).
Sorry, noticed that after clicking the image and making it huge..LOL!!
 
Thanks for the advise, are you using Apex for your timers? You hit the nail on the head from my vantage, that exactly what the system does, it uses the OSC function changed a little from the diagram) currently 40 seconds ON every 15 minutes, the pH in normal increments is used to turn on Kalk or RODI solenoids, but, if pH hits 8.4 the Apex drops power to the Smart ATO. The theory is 40 seconds every 15 minutes, at 3 PSI (system is in the basement, so this is just slightly faster than a drip) with full Kalk solution, should not exceed pH of 8.5 even if smart ATO fails, I have tested this a few times, by, bypassing the Smart ATO solenoid.

No, I still use my RKL and very happy with it... Had it for years! I see what you want to aim for, but have no experience with solenoids nor using my RODI hooked to my tank.. Do you know how much water you evaporate in 24hrs?
 
I only clean it out once a year or so. I keep the intake for the dosing pump about 6 inches off the bottom. Limewater is self purifying , you just need to let stuff settle. I add more lime at each fill up. I leave the residue in the bottom, until I'm ready to clean. As long as you aren't sucking up residue there is no issue. Most everything settles over night. I've never had an issue in over 5 years. I know there's a long thread on RC about it by Randy in the chemistry section.

I remember reading something on rc when i dosed kalk that that sediment that settles in the bottom is actually a good thing to have and to keep some at the bottom . It been yrs since i dosed kalk but believe they said something like it keeps tge kalk stabile or something in that matter
 
Thanks for the advise, are you using Apex for your timers? You hit the nail on the head from my vantage, that exactly what the system does, it uses the OSC function changed a little from the diagram) currently 40 seconds ON every 15 minutes, the pH in normal increments is used to turn on Kalk or RODI solenoids, but, if pH hits 8.4 the Apex drops power to the Smart ATO. The theory is 40 seconds every 15 minutes, at 3 PSI (system is in the basement, so this is just slightly faster than a drip) with full Kalk solution, should not exceed pH of 8.5 even if smart ATO fails, I have tested this a few times, by, bypassing the Smart ATO solenoid.

Aren't you going to have issues with the Smart ATO? I have this ATO. What makes it "smart" is its ability to know if the pump goes on for a longer time period than the previous pumping session. If it does, this tells the system that something is wrong (possibly a leak) and shuts off the ATO and turns on an alarm. If your apex is turning it on and off, it will forget how long the previous pump was.

I'm guessing you e thought this out, but thought I'd put it out there.
 
Aren't you going to have issues with the Smart ATO? I have this ATO. What makes it "smart" is its ability to know if the pump goes on for a longer time period than the previous pumping session. If it does, this tells the system that something is wrong (possibly a leak) and shuts off the ATO and turns on an alarm. If your apex is turning it on and off, it will forget how long the previous pump was.

I'm guessing you e thought this out, but thought I'd put it out there.
Good point, I have thought it out, but, it was the best two brain idea I could come up with. The 1st assumption I had to make when designing the system, is that everything WILL fail. The hope or stretch is that the systems (components) are diverse enough that the cause of one failure will not be cascading leading to a second simultaneous failure. My definition of simultaneous for this project is 8-12 hour period while I'm at work or sleeping. So the Smart ATO decision is/was am I safer to let Smart ATO stay powered and use it's secondary timer protection immediately or power cycle it and get tertiary protection. Since the OSC function of Apex is primary protection, pH/Salinity is secondary protection and Smart ATO timers often think too much (shut off because that period was excessive), I chose tertiary protection. So... the failure scenario would be the EB8 power sticks on Apex OSC has no effect, Apex fails to cut power to Smart ATO and fails to cut power to the solenoids based on pH/Salinity, so Smart ATO runs normal fills for 40 seconds then shuts off next time at 80 seconds. This is a highly unlikely chain of events, but, clearly allows both computers (brains) to attempt to shutdown the system if either one sees a problem. Best of all Smart ATO would have a clean full sump start, in that failure scenario leaving the timer much shorter than you would need to have to cover all fill scenarios. Most people using Smart ATO start it will the sump a little lower than normal to insure the 2x timer shutoff isn't happening during low humidity / high evaporation.
 
No, I still use my RKL and very happy with it... Had it for years! I see what you want to aim for, but have no experience with solenoids nor using my RODI hooked to my tank.. Do you know how much water you evaporate in 24hrs?


Yep 1 gallon in the summer when the tank heaters run less (Nest thermostats set to 74 degrees) and house humidity is high and 2 gallons in the winter (Nest thermostats set to 72 degrees) and house humidity is low.
 
1jwampler, I have a somewhat similar setup, in that I use an Apex, run kalk via ATO, have programmed PH fail safes, and RODI tied in directly.

I've found that there are 2 scenarios that lead me to add 1 more circuit than you are using. The scenarios are 1) high PH & high evap 2) skimmer excitement, filling external skimmate container and requiring sump refill...which runs into 1. Note: the external skimmate container has a sensor tied into the Apex to turn off the skimmer when full. Size of the skimmate container matters relative to your total system volume, because you ATO may be called on to pump that much into the sump when a skimmer goes nuts.

Neither are regular occurrences, but they for sure happen a couple times a year and because I travel regularly for work my system needs to be able to go 2wks or more without oversight.

1) can lead to the probes not being submerged or worse the return pump sucking air.
2) happened the last time I had a fish kill another...and then a couple days later skimmer went nuts...apex shut off the skimmer after filling the skimmate bucket and sent me txt....and lead to 1).

So, like heaters, I have a redundant ATO.
View attachment 15176

The primary uses a pressure switch and a peristaltic pump to push through the kalk stirrer. And the backup is a SmartATO with optical sensor set about an inch lower than the primary ATO.

The other difference is instead of a pressure vessel I use the Avast Barrel tender to manage the RODI refill into the 3g ATO container. The Avast sensors are pressure switches, not float. The container is never empty and the system never requires more than 1g top off at one time (scenario 2).
 
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1jwampler, I have a somewhat similar setup, in that I use an Apex, run kalk via ATO, have programmed PH fail safes, and RODI tied in directly.
Very impressive setup ultimatemj; even more so, knowing you can leave the tank for two weeks. My worst case scenario is when my wife and I are on vacation, the housekeeper would only look at the tank once a day or maybe every other day. I never thought of the skimmer overflow(over active), but, on accident I don't have to worry about it, since the cup is large enough to hold a week's effluent and I don't have an external container, so my worst case (at this time) is the effluent goes back into the sump, not desirable, but, probably not going to cause any lasting damage.

I'm a little lost on how the high evaporation scenario may impact my system. I love that you posted it and made me think...... This said, I would think overly high evaporation would lead to salinity going up prior to the probes being exposed to air (at least in my tank/sump, I would have to lose 10 gallons), this scenario would hopefully be caught two ways, one by the extra capacity built into the system, which used the APEX OSC function to allow an extra 1.5-2.0 gallons/day over the tank normal worst case evaporation. The second would be a high salinity alarm from APEX or alarm from Reeftronix about no communication if it were APEX that failed.

Since I reset Smart ATO every time it runs, it won't stop filling due to high evaporation on first round, which effectively is every non-malfunctioned fill. I know I don't get the 1st line of defense from Smart ATO, but, both the APEX EB to malfunction ON and Smart to malfunction ON to get in a scenario where overflow is a risk. I would then get email alerts about low salinity (I have salinity emails set to < 34.8 and > 35.4) or from Reeftronix saying lost communication with APEX (assuming a total APEX failure) and at 3 PSI I only get about a gallon an hour from the basement, which would give me 8-12 hours to get home before I hit 30 PPT and or my sump overflowed.

Do you think I missed something on evaporation?

Thanks,
JW
 
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Thanks, my longest time away from my tank (with no oversight) is 26 days!

WeekS away is one of the reasons for having an external skimmate container ;-) But that brings a need for the system to be able to react to the skimmer overflowing a skimmate container full of water out in short order...which looks like a high evap situation to the system.

A 1g skimmate container holds about a month's worth of skimmate, when behaving properly, and an ATO adding 1g of RODI to my 75g system doesn't move salinity appreciably. Note, this is related to why you don't want to just plumb skimmate to a floor drain LOL

The high evap scenario is typically from GFAC drying your house out in winter or your skimmer tanking fluid out :)

It is looks like this:
-Evap starts ATO, which raises PH to 8.4 and get's turned OFF.
-Evap continues, but PH stays high due to daytime photosynthesis period...keeping ATO OFF.
-PH begins dropping in evening and ATO kicks on, but due to lower volume in sump the alkalinty quickly raises the PH back to 8.4 more quickly and shuts ATO OFF.
-The risk is this becomes a "death spiral" and the water level in the sump continues to go lower and lower, as the ATO keeps getting shut OFF.
-Salinity going up is not good, but worse can happen
- pump can cavitate (suck air), floats can dry out and get stuck, triggering Apex programming, etc.
- depending on how your probes are placed this can trigger other ugly activity...such as temp sensor gets exposed to ambient air and turns on all heaters, but can never attain your target 78? Don't ask me how I know this ;(

The other thing similar to the "high evap" scenario is when the primary ATO sensor fails and ATO doesn't happen...sump level goes lower and lower until something lets you know.

So, I have 2 ATOs. The back up only pumps RODI (avoiding the PH issue).

To improve on this, my intention is to replace the SmartATO (that occasionally decides to go into fault mode for no reason) with a second Avast ATO pressure switch and peripump....and a run it through a float valve. This is to be reliable and avoid the risk of overfill without any programming needed.

Regards,
M.J.
 
Thanks, my longest time away from my tank (with no oversight) is 26 days!
M.J.

26 days.... Awesome.. I now understand where you are coming from. Our systems are very parallel, you are using a 2nd ATO and depending on Smart ATO to keep the daily top off in check. I'm using direct RODI and Kalk with 2 solenoids to keep pH in check and APEX to keep daily top off in check, your backup to the backup is the 2nd ATO, my backup to the backup is the Smart ATO. So, if you take a look at my drawing, i engage APEX to pump 50/50 saturated Kalk solution and straight RODI from 8.30 to 8.33, above 8.33, I pump only straight RODI and below 8.3 I pump only straight saturated Kalk solution. I think this takes care of your evaporation problem, in that if pH is over 8.33 (no failure experienced) and Salinity is above 34.7 I pump only RODI, so if the tank experienced high evaporation, only the Kalk required to hold 8.33 would be pumped.

What are your thoughts MJ?

Thanks,
JW
 
Your interpretation oh my system is close, but if you look at my pic you'll see the SmartATO sensor is about an inch below the primary ATO sensor....I pump kalk via the primary and use the SmartATO purely as backup for when PH is above 8.4 and not coming down.

Based on some of RHF's comments, I may push the primary shutoff number up to 8.5. As it stands, it's rare for the SmartATO to come on....just couple times a year....but my ALK demand is growing, hence the push from 8.4 to 8.5 to allow for a bit more kalk during the day.

At some point in likely to separate the systems and run kalk on a time based dosage, this is just how it all got started to support weeks away.

Here you can see how my ATO triggers frequently during the day, maintains 8.4 PH and then it takes x hours for it to drop and trigger again in the morning.
e11b572e835181de68c2c4a991a200d3.jpg


My next change is most likely the addition of a conductivity probe on the kalk stirrer to let me know when it needs reloaded.

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My next change is most likely the addition of a conductivity probe on the kalk stirrer to let me know when it needs reloaded.
MJ,
How are you planning to mount the conductivity probe in the stirrer?

Looks like even our graphs match, your Smart ATO is doing what my RODI Solenoid is doing.
 
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