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  #21  
Old 07-15-2010, 06:25 AM
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Default Electrical



<More detail coming soon>

Last edited by abcha0s; 03-29-2011 at 09:12 PM.
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Old 07-15-2010, 06:25 AM
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Default Sequencing and Automation



<more detail coming soon>

Last edited by abcha0s; 03-29-2011 at 10:04 PM.
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Old 07-15-2010, 06:26 AM
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Default Neptune Apex Controller(s)

I have a love hate relationship with my Neptune Apex Controllers. I love the features and what they are capable of, but I just don't trust them long term unattended. I haven't really had a problem - so to speak - but every now and then they do weird things.

My biggest complaint with the system has to be with the Triac based outlets (1-3, 5-7) on the EB8. I have had all kinds of problems with these outlets not properly shutting off. I engaged Neptune support about this and while they were responsive, they basically told me that I was crazy. Honestly - they just wouldn't believe the problems I was having. I did get this official response:

Quote:
It is not the size of the load that determines whether or not the triac has trouble shutting it off. It is the power factor (how much current lags voltage), that causes the problem. Some inductive loads (motors) do no power factor correction and that is why the issue is mostly with small pumps. Larger pumps have power factor correction.

These are the ways to solve the problem:
  • Plug an additional load (small light bulb/wall wart transformer/fan) in parallel with the load.
  • Use a socket expansion box to control the device.
  • Use a DC4 or DC4HD to control the device.
Now of course they have the EB4 which also solves this problem.

Anyways...

I have elected to use two Apex Controllers on my system. The Intent is such that if one fails, the other will continue to operate. The two systems are electrically isolated.

Any of the systems which would be deemed critical, should be split across the two controllers.
Controller A - Return Pump 1, Heater 1, Heater 2, Skimmer Pump 1, ATO 1, Auto Feeder 1
Controller B - Return Pump 2, Heater 3, Heater 4, Skimmer Pump 2, ATO 2, Auto Feeder 2
The following section documents the configuration and application of the Neptune Apex Controllers. Keep in mind that this is a work in progress. I will keep this page updated as the program is expanded and enhanced.

Please - If you see obvious errors or ways in which I could improve the code, please let me know.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Neptune Systems Apex Controller - Primary
Attached Probes: Tank pH, Tank Temp, Tank Orp
Attached Modules: 2 x EB8, Breakout Box
Attached Switches: 6
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Profiles

Day-R
type:Pump
minIntensity: 40
maxIntensity: 100
sync: Enable
div10: Disable
intOffTime: 88
OnTime: 88
OffTime: 0
Day-L
type:Pump
minIntensity: 40
maxIntensity: 100
sync: Enable
div10: Disable
intOffTime: 0
OnTime: 88
OffTime: 88

Variable Speed Outlets

VS1_Tunze-L (VAR 1)
Set Day-L
If Time 00:00 to 23:59 Then Day-L
If FeedA 004 Then OFF
VS2_Tunze-R (VAR 2)
Set Day-R
If Time 00:00 to 23:59 Then Day-R
If FeedA 004 Then OFF
VS3_Wavebox (VAR 3)
Set OFF
Fallback OFF
If Outlet MorningCalm = ON Then ON
VarSpd4_I4 (VAR 4)
Not currently used

Variable Speed Outlets

SndAlm_I6
Set OFF
SndWrn_I7
Set OFF
EmailAlm_I5
Set OFF
If Temp > 82.0 Then ON
If Temp < 75.0 Then ON

Virtual Outlets - Used for programming

MorningCalm
Fallback OFF
Set OFF
If Time 04:00 to 10:00 Then ON

EB8 - Left Side of Tank

Skimmer-T1
Fallback ON
Set ON
Skimmer-T2
Fallback ON
Set ON
Pump-Pellets
Fallback ON
Set ON
Unused-4_4
Fallback ON
Set ON
Unused-4_5
Fallback ON
Set ON
Unused-4_6
Fallback ON
Set ON
Unused-4_7
Fallback ON
Set ON
Unused-4_8
Fallback ON
Set ON

EB8 - Right Side of Tank

Pump_ReturnL
Fallback ON
Set ON
Pump_ReturnR
Fallback ON
Set ON
Light_Temp
Fallback OFF
Set OFF
If Time 09:30 to 21:30 Then ON
If Temp > 82.0 Then OFF
Min Time 030:00 Then OFF
Light_Fuge
Fallback OFF
Set OFF
If Time 21:25 to 10:00 Then ON
If Temp > 81.0 Then OFF
Min Time 030:00 Then OFF
Heater1
Fallback OFF
If Temp < 77.8 Then ON
If Temp > 78.0 Then OFF
Heater2
Fallback OFF
If Temp < 77.8 Then ON
If Temp > 78.0 Then OFF
Heater3
Fallback ON
Set ON
If Temp < 77.8 Then ON
If Temp > 78.0 Then OFF
Heater4
Fallback ON
Set ON
If Temp < 77.8 Then ON
If Temp > 78.0 Then OFF
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Neptune Systems Apex Controller Lite - Secondary
Attached Probes: n/a
Attached Modules: n/a
Attached Switches: n/a
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

This controller is currently in use on my 90G tank and will remain there until the tank is shut down. I will update the configuration when the controller comes online.

Last edited by abcha0s; 03-29-2011 at 09:59 PM.
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  #24  
Old 07-15-2010, 06:27 AM
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Default Flow (Tunze 6215, 6205 / VorTech MP60w ES)

Hardware

Flow within the tank is currently as follows:
Return Pumps: 2 of Eheim 1262 (600Gph)
Power Heads: 2 of Tunze 6205 (1,320 to 5,811 USgal./h), 2 of Ecotech VorTech MP60w ES (3500 to 7500 gph)
Wavebox: Seems to be a lot.
Total Flow (Maximum):
Return pumps: 1,200 gph
Tunze 6205s: 11,622
VorTech MP60s : 15,000
Wavebox: Lots

Total: 27,822 + Wavebox
Turnover: 27,822G (Flow) / 300G (Tank) = 92.74X + Wavebox

Note: Because of the variable nature of the powerheads, the actual turnover is difficult to calculate.
Closed loops vs. powerheads

In this tank, all of the flow will be provided by powerheads.

By far the best resource for closed loop systems is Oceans Motions. I used a closed loop on my previous 90G tank. It was based on two seperate loops (left and right) using an independant Oceans Motion Super Squirt 4-way on each side. Each loop was driven by a Poseidon PS4 pump. The flow patterns were very dynamic and the system was silent. Overall, it worked perfectly but I ultimately pulled it out and replaced it with Tunze powerheads.

There was really only one thing that I liked about the closed loop when compared to powerheads. When viewing the tank through the front pannel, it was barely visible. Aesthetically a closed loop wins every time, but that seems to be where the benefits end.

I pulled the closed loop out of my 90G for several reasons. The first being the heat generated by the two Poseidon pumps. The second being the electrical consumption and the third being the maintenance of the pumps and plumbing.

Note: I realize that Poseidon pumps are known to have unusually high heat transfer charecteristics, but they are also unusually silent. Another pump might have solved my heat issue, but I would then have a noise issue.

Granted there are some cool things that you can do with a closed loop which aren't possible with powerheads, but the reverse is also true. Consider the various modes that a Vortech pump can operate in.

I also like the fact that I can move the powerheads as the tank matures and corals grow. I can ramp up and down between 30% and 100% power. There are no holes drilled in my tank and cleaning is as easy as a vinigar soak.

In my opinion, simple is always better. Although I completely agree that powerheads are ugly, there's nothing simpler than a powerhead.

Surface Skimming - Powerhead orientation

It's necessary to skim the entire tank surface. The most effecient way to accomplish this is with a coast-to-coast overflow, but a coast-to-coast overflow doesn't work well with waves. It surprising how poluted the water surface becomes if it is not properly skimmed. The consequence of bad surface water is reduced light penetration, poor gas exchange and a visible scum build up.

Successfully skimming the surface of the tank really has everything to do with the proper placement of return plumbing, powerheads and close loop intake/outlets. It took a lot of experimenting to get this perfect on my tank.

With only the return pumps running, the surface water in my tank remains almost completely flat. Almost like a sheet of glass.



In this first image, the dark blue is the surface area that is skimmed most effeciently. The light blue area is also skimmed, but not nearly as rapidly. The easiest way to observe this is with floating fish food. If you drop it in the far front corner, it is eventually skimmed but tends to circle around a bit first.

When I first positioned the powerheads in the tank, the orientation was based on flow within the tank and did not give consideration to the surface water. This resulted in a bulge roughly centered in the tank. This is the logical consequence of two opposing powerheads aimed towards the center area of the tank.



The problem here is that the surface water at the edges is not skimmed at all and the scum quickly builds up. In the image shown above, the black lines indicate areas where no surface skimming occours. Protiens on the surface tend to travel down hill. With the center bulge, they were trapped at the edges.

To really achieve proper surface skimming with a center overflow, some of the flow needs to be oriented at the outside edges. This creates a slop inwards and allows the entire surface to be skimmed.



A smaller bulge in the center is still acceptable, but the outer edges should be within the confines of the overflow.

Connecting the Powerheads to the Apex Controller

This is pretty straight forward. The Apex controller has 4 variable speed ports (0-10V). Physically, there are two RJ45 ports, so a special cable is required. The cable splits the port and has two male Tunze connectors at the other end.

Important: Do not allow your Tunze powerheads to run at a power level between 1% and 29%. The Tunze controllers will not allow you to do this, but the Apex will. You can ruin your powerheads by doing this. I would assume everyone already knows this, but just in case...

Connecting the Tunze Wavebox to the Apex Controller

It would be great if the Apex could control the wavebox directly, but for most people it is not possible to set the frequency of oscillation to match the resonant frequency of the tank. This is because the smallest increment of time on the Apex is .1 seconds. It is possible that the resonant frequency of your tank will be an exact multiple of .1s, but this is somewhat unlikely. A much smaller increment such as .01 would likely be required.

There are a number of benefits of controlling the wavebox directly from the Apex.
  • Include the wavemaxer in feed timers.
  • Night mode that isn't dependant on a photocell.
  • Single point of control for all pumps.
There's a trick to make this work.

I used the wavebox controller (6091) to set the wave and used the Apex controller to enable/disable the 6091 wave function.

The wiring diagram looks like this:



The Y adapter isn't strictly necessary but it makes things much easier because it serves as a gender changer for the cables. Both the wavebox controller (6091) and Apex have male ends whereas the Y adapter is female.

The second wavebox isn't necessary either. However, if two waveboxes are deployed in this configuration, they have to be on the same end of the tank running in synchronous mode.

The jumper in the 6091 controller needs to be set to slave mode to enable control from the Apex. You have to open the 6091 controller to change the jumper. This is explained in the user manual.

I haven't spent a lot of time experimenting with different voltages, but in the simplest of terms:

10V from Apex = 6091 stops creating a wave. The pump shuts off.
0V from Apex = 6091 operates in wave mode.

This seems counter intuitive, but it does make sense on one front. If the 6091 controller is disconnected from the Apex it operates independently and generates a wave. Therefore, it is not dependant on the Apex for operation; rather it is dependent on the Apex to know when to shut off.

Feeding

<rough notes>
I've found that shutting off the return pumps during feeding can be problematic. On my 90G this would cause the water level in the sump to rise, which meant that I had to shut off the ATOs. It also allows water to back siphon from the display which is supposed to be prevented by the return line check valves, but in practice it really only partially works.

I have programmed a feed mode for the Tunze 6205 powerheads and wave maker. It basically stops the pumps completely and then pulses each pump simultaneously for 1 second once every 10 seconds at 40% power.

The VorTech MP60s also have a built in feed mode.
Night Mode

I believe in reduced flow at night.

<<<This post is not yet finished. I am using the edit feature to add content. Check back later.>>>

Last edited by abcha0s; 03-29-2011 at 09:55 PM.
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Old 07-15-2010, 06:27 AM
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Default Autofeeders

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Old 07-15-2010, 06:28 AM
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Default Lighting

post 26

Last edited by abcha0s; 03-29-2011 at 09:53 PM.
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Old 07-15-2010, 06:28 AM
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Default Heating and Cooling

The target temp for my tank is:
Low Temp: 78F (25.56C)
High Temp: 78.8F (26C)
The goal is to maximize temperature stability within this range. The tank temperature should fluctuate less than 0.5 degrees Fahrenheit.

Cooling
As it turns out, the more energy efficient hardware is, the less heat it produces. All of my hardware was selected based in part on energy efficiency. Most notable is the LED lighting which is significantly more energy efficient then alternative lighting sources. The upside to this is very little heat transfer into the water. For most of the year, I do not need any form of cooling.

The tank is located in my basement which tends to stay slightly cooler than the rest of the house. There is constant evaporation which translates to heat loss, so the tank tends to find a temperature balance slightly below the ambient room temperature. For the occasional heat wave, I have a fan in the sump that blows over the water surface to increase evaporation and cooling. The fan is connected to the Apex controller for temperature control.

Heating
Ironically, the downside to energy efficiency is also a lack of heat transfer into the water. My tank water stabilizes at room temperature and needs to be constantly heated (day and night). The energy consumption of the heaters required to keep the tank at a constant 78F cancels out a significant portion of the savings gained through energy efficient hardware. In my case I estimate this to be approximately 700 watts (~6 Amp/h) of heating.

Background Reading

BeanAnimal - Aqarium Heaters: What you need to know!

BeanAnimal - Thermodynamics for the Reef Aquarist

abcha0s - My Marineland 300W Stealth Pro Heater Exploded!

Heating my tank

I am using 4 300W Titanium Heating Tubes.
  • The Heaters are Finnex Titanium Heaters. I don't recommend this brand, nor expect it to work indefinitely. With that said, I haven't found any brand of heater where people haven't complained about failures. Ebo Jager seems to have the best overall user reviews, but it's still not hard to find incidences of failure.
  • Based on a very general rule of thumb, I need 3-5W of heating per gallon of tank water. For a 300G tank, this equates to 900W to 1500W.
  • I had heard that Titanium heaters were more efficient than glass heaters. After testing the two types of heaters I can't really see much of a difference. If the Titanium heaters are more efficient, it is a very small percentage.
  • I went with a heater without a thermostat because the thermostat is likely to fail anyway. One less component to worry about.
  • The Apex Energy Bar 8 (EB8) is rated to 5Amps per outlet. The basically means that the biggest heater I can use is 500W.
  • Several small heaters are better than one larger heater.
  • I went with 4 of the 300W heaters instead of 3 of the 500W heaters for efficiency and redundancy reasons. The 300W heaters have a 10 inch heating tube. The 500W heaters have an 11.5 inch heating tube. My assumption is that the diameter of the tubes is the same; therefore, the 300W version has 30W per inch. The 500W has 43.5W per inch. More surface area should make the 300W more efficient.
I know from observation that two 300W heaters (600 Watts total) running continuously will heat my tank about 9F (5C) above the ambient room temperature. To maintain a stable tank temperature, I really need a minimum of three 300W heaters (900 Watts total). In this configuration, the additional 300 Watt heater operates about 75% of the time.



This graph shows three interesting things.
  • The data to the left of 8:45pm is my tank with 2x300W heaters. You can see that it struggles to keep the temp between about 76.5 and 77.5. At this point, the heaters are on constantly and are unable to raise the temp to the target of 78F.
  • The drop in temperature at around 8:45 occured when I turned the heaters off to do some maintenace in the sump. The temperature dropped very rapidly.
    Note: The temperature probe is in the sump. At the time these temperature measurements were taken, the return pumps were also shutoff meaning that the sump was isolated from the display. The display tank has thicker glass so is likely somewhat more insulated, but I wouldn't count on that to keep the tank warm. This could be a real problem in a power outage.
  • The data to the right of about 10pm is the tank with 3x300W heaters. With the increased heating capacity, the heaters really have no problem reaching the target temp.
The heaters are installed in the return section of the sump. The temperature probe is in the chamber right before the return section. Therefore, heated water has to circulate through the tank and back to the sump before the temperature sensor is able to detect a change. There is an approximate 0.5F temperature differential between the display tank and the sump.



The 4 Titanium Heaters are split evenly between two Apex controllers on independent EB8s. Each EB8 is connected to a separate 15A circuit. This should allow for the failure of three heating tubes before the tank water temperature begins to drop. The failure of one Apex/EB8 or 15A circuit would result in the loss of 2 heating tubes. The heating tubes don't have a thermostat, so they are basically stuck on already. If for some reason the EB8 outlets on one Apex stuck on, the other Apex should shut both heaters off. If one Apex completely failed, the surviving controller could maintain the tank temperature. This equates to "no single point of failure".

Another benefit of using two Apex controllers with independent temperature probes is the ability to identify any calibration drift between the probes. As the probes are both installed in the same sump chamber, the temperature readings should always be within about 0.1F of each other. If this drift increases, it is an indication that one of the probes is not operating at peak performance and that maintenance should be preformed.

Finally, if the temperature of the tank does deviate either up or down, both Apex controllers are configured to send email alerts to my phone.

When operating normally, the temperature characteristics should look like this:


Last edited by abcha0s; 03-29-2011 at 09:53 PM.
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  #28  
Old 07-15-2010, 06:29 AM
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Default Reactor Loop (biopellets, carbon, phos)

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Old 07-15-2010, 06:29 AM
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Default Tunze Master DOC 9440 Skimmer

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Old 07-15-2010, 06:30 AM
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Default ATO (Automatic Top Off)

<This design is currently in draft status - There are some minor modifications planned for the final implementation - Check back later>

Pretext: I’ve had my ATO fail while on holidays. This caused the sump return chamber to completely evaporate leading to a subsequent failure of the return pump. After fixing the ATO and replacing the return pump, the ATO did what it was supposed to do and pumped 10 gallons of saturated Kalk water (pH 12.4) back into the system. The result was a pH spike reaching upwards of 9.5. While I was able to recover from this without a tank crash and better yet, without losing any wildlife, it drove home the importance of a reliable ATO. In my opinion, it is one of the more critical components and can potentially fail without warning.

Requirements: In keeping with the guiding principles, this aspect of the system has to be completely redundant all the way through from the breaker panel to the tank. It needs to be constantly monitored and should be able to identify and alert a failure event. In the event of any single failure, it should continue to operate without impact the tank.

Addition considerations include:

• RO units are not very efficient when run for a short duration. Therefore, the ideal situation is to fill the reservoirs in one cycle of the RO unit.

• The Tunze osmolator water pumps seem to lose their prime when they run dry. I’ve often had to suck water into the pump to get it started. Perhaps it’s just my pump, but the system needs to prevent these pumps from ever running dry.

• Kalkwasser is to be dosed through the ATO system, so there should be some safety measures in place.

• The return chamber of the sump does not hold sufficient water volume to survive a failure of the ATO system for an extended period of time. Making this chamber bigger would have meant sacrificing space elsewhere.

Diagram Conventions: The following table depicts the conventions used in this document.



System Schematic: The design I came up with is probably overkill if the ATO was the only consideration. However, many of the redundant systems utilized by the ATO are also being used by other systems.



The Solenoid Valves: The solenoid valves are closed by default. They are opened by the Apex controllers and solve the problem of an inefficient RO unit during the first few minutes of operation. It’s not a question of water high in TDS making it into the tank as the DI resin takes care of this. It’s really a cost savings measure designed to protect the RO membrane and the DI cartridges.

The easiest way to control the filling of the reservoir would be to have the sensors that are installed in the reservoir open the solenoid. It’s easy enough with the Apex controller to open the solenoid for a specified period of time (say 1 hour) whenever it detects a sensor event. However, I don’t really trust these sensors enough to completely rely on them. I am comfortable using them as a backup but I want a more reliable means of refilling the reservoir on a routine basis.

The solution is really simple. Each day at a pre-set time and for a pre-set duration the solenoid opens and the reservoir is allowed to fill. The amount of time required to refill the reservoir (assuming it is nearly empty) is estimated and a safety factor added. While the reservoir is filling, the Tunze ATO is shut off so that once full, no water is removed from the reservoir until the cycle is completed. The RO units are equipped with shutoff valves and will automatically stop when once the resevoir float valve creates sufficient back presure.

Another benefit of filling the reservoir based on time is that if the float valve in the reservoir were to fail open, the water damage would be limited. The solution provides a double shut off. The first being the float valve, and the second being elapsed time. I could install a high water sensor in the reservoir as a third safety, but I’m not sure that it is necessary.

The Primary and Secondary ATO systems are programmed to fill the respective reservoir at different times during the day. In the event that the rate of evaporation is higher than anticipated on any given day, the sensors in the reservoir will open the RO solenoid and fill the reservoir as would otherwise be expected.

The final benefit of a timed system is that the reservoirs would never randomly start filling at the same time.

Controlling pH: The use of Kalkwasser in the ATO necessitates a brief discussion of pH. The tank will have a natural pH swing based in part on the light cycle and the consumption of CO2 through organic processes. Using the Apex controller and pH sensor, we can manipulate the natural swing a bit.

NSW (Natural Sea Water) has a pH of between 8.0 and 8.3, but is generally estimated at 8.2. For a variety of reasons, I will target 8.2 as my “ideal” pH. I will consider of range of 8.1 to 8.3 to be within the acceptable ideal. I will tolerate a swing of 8.05 to 8.35 before trying to further adjust the system.

It is suggested that minimizing the pH swing is more important than hitting a precise value. For example a pH swing from 7.9 to 8.1 is probably better than a pH swing of 8.0 to 8.4 even though the average is closer to ideal.

• The Kalkwasser doser will always be operational except where the pH rises above 8.3. There is no consideration for night and day. Only the pH of the system is considered. If the pH rises above 8.3 the controller will stop operation of the secondary ATO system and only the primary ATO will function. However, If any of the low water level alerts are triggered, the pH condition will be ignored and the secondary ATO will be turned back on. I figure it’s better to allow Kalkwasser to be dosed without regard to pH, than to have the entire system fail.

• If the pH rises above 8.2, the Calcium reactor will be activated. This system is independent of the ATO system, but will serve to lower the pH and keep it closer to ideal.

• The Kalkwasser mixer and Calcium reactor operating in tandem provide a number of benefits which we can discuss in another section.

The obvious question at this point should be “Do you trust you pH measurement instruments enough to rely on them”?

There is a 2 part answer to this question.

1) It doesn’t really matter if they are completely accurate as it is more about the swing then the precise pH value. I consider it an acceptable error if the pH is actually swinging from 8.0 to 8.2 rather than the target of 8.1 to 8.3.

2) I will have some insight into the calibration and operation of the pH probes because I will have two pH probes connected to two separate Apex controllers. Once calibrated, these probes should have identical readings. If either probe produces readings outside of an expected baseline, I will know further investigation is warranted.

Water Lines: The difference between the high water mark and the low water mark does not have to be very big. It should be greater than the rate of evaporation between the two water levels such that the primary pump is not activated during a kalk mixing cycle (1h 10m) or a reservoir fill cycle (up to 2h).



Primary ATO: The primary ATO holds the water level at the ‘Low Water Line’ and is always on. The only exception is while the reservoir is being filled, which is programmed to occur an hour before the lights come on. This time was selected because of the predictably low pH at this time.



This is pretty standard stuff here. The only extras are the float sensor attached to the Apex one of which is in the sump and the other of which is in the reservoir.

Secondary ATO: The secondary ATO holds the water level at the ‘high’ mark and is turned on and off according to the following logic:

• Kalk Mixer On (10m) – Tunze Osmolator Off (1h 10m)
• Kalk Mixer is On approximately 10m every 4 hours.
• The Tunze Osmolator is off during a reservoir fill cycle.
• The start time for a reservoir fill cycle is programmed to coincide with a kalk mix cycle, but is estimated at 2H.

What I’m trying to avoid here is pushing water through the Kalkwasser mixer and into the tank while the mixer is in operation. The kalk needs about an hour to settle after it has been mixed.



The reservoir is filled just before the lights go off. This time was selected because of the predictably high pH at this time.

Dual ATO: The two independently operating ATO systems provide a backup to each other. The system can withstand any single failure without crashing the tank.

Limitations: The systems not perfect. There are some failure scenarios that warrant a note. Although unlikely to occur, there is always a possibility.

• If either of the Kent Marine Float Valves fail, there is a potential that the reservoir will overflow during a scheduled fill cycle. To mitigate this, the overflowing water would pool in the sump area of the stand. This area is sealed for leakage and should hold a significant amount of water before spilling onto the carpet. A water on the floor alarm could also be triggered.

• The RO/DI units could spring a leak before the check valve. They are installed in the furnace room which has a floor drain. I am confident that water would be contained in this area.

• The John Guest fitting could fail at the reservoir. This could potentially be bad, but is reasonably unlikely to occur. The damage would be limited to my basement carpet and the tank should be just fine.

• If the primary ATO fails for any reason, then the secondary ATO is forced into an on state. This effectively disables the pH controls. However, the rate of kalkwasser addition to the tank is still limited by the rate of evaporation and the Calcium reactor would still be on. I don’t anticipate a significant pH spike.

• Larger reservoirs might make things a little easier and reduce the margin for error. However, they would also take up more space which is really at a premium under my tank.

• It would be nice if the two Apex controllers were aware of each other. Unfortunately, they are not.

Feed Cycles: I’d like to be able to stop the return pumps for feeding. I use a check valve on the return lines to limit the amount of water that back siphons into the sump. Don’t worry, the check valves are not safety features, rather just a convenience factor (the sump can hold the water if need be). However, the water level inevitably changes with the small volume of extra water and the high level alarm goes off. The other problem is when the pumps start up the water level in the sump drops while the overflow stabilizes and the ATOs start trying to compensate.

The solution is to shut off both of the Tunze Osmolators during the feed cycle and turn them back on 10 minutes after the feed cycle completes. The Apex controller has this feature built in.

Last edited by abcha0s; 03-09-2011 at 10:23 PM.
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