CO2

In a prior post I provided an explanation of the plumbing in the stand under my Son of Kahuna aquarium. But a lot of it did not really make sense (like the various solenoids) without a corresponding electrical diagram. So here it is. Here’s a link to the plumbing post. As you go through this diagram, sometimes it may be helpful to refer back to that.

The diagram above documents my electrical wiring. Clicking on it should bring up a larger, more usable picture. While there may be a lot of wires, it’s actually fairly simple. In fact, getting stuff to work was easy. But managing all those wires in the stand (where do you put all the excess wire?) wound up as a challenge in setting up the stand. But I think I took care of it. I’ll do a “physical stand” post later where I show how I dealt with that and other physical challenges.

Objectives

1. I wanted it to be secure and reliable (no loose connections)
2. I wanted it to be manageable (I’ll show that in the physical stand post)
3. I wanted it all controlled by a single unit

Electrical Overview

Looking in the diagram you can see at on the left a Neptune Systems AquaController III (AC III). This simple device controls most of what is running in my stand. It can be controlled, or “programmed”, with the little buttons on front. But it also has a web server in it that displays web pages that you can control it from. That’s my preferred method of managing the AC III’s settings. But that requires that it be hooked up to an Ethernet network. I’ll get to that…

The power itself in the stand is simple. I’ve got a single multi-outlet powerstrip plugged into the wall. Everything that is not turned on and off by the AC III plugs into that. That list is the WiFi access point, three little halogen lights inside the stand (for illumination of electrical and plumbing equipment), and a ground probe. That ground probe is mounted in my plumbing (always wet) to capture any stray electrical current - if any. And finally, the AquaController’s Direct Connect 8’s (DC8) are not turned on/off. They are “on” all the time.

The DC8’s are really simple. They have a proprietary control cable that plugs into the AC III. Or rather one plugs into the AC III, and the 2^nd DC8 is daisy-chained to the first one. The AC III individually controls each power outlet on the DC8’s sending control signals over that proprietary wire to turn the power to each individual plug on, or off, as needed.

The things that are turned on and off by the AC III all plug into a DC8. And the sockets are really solid - they grip a plug really tightly. Nothing is going to fall out accidentally.

Controlled Devices:

Lights

Turn on and off a little after sunset, and a little after sundown. The AC III would allow a normal “turn on at this time, off at that time” sort of programming, but it also understands seasonal variations in day lengths, and allows small incremental changes based on season.

Primary Pump

In my plumbing diagram you can see that this pump is on a filtration loop that has a lot of other devices on it, like all three heaters, CO2, UV and more. So I’ve got the AC III set up so that if this pump is turned off, then the AC III knows to turn all that other stuff off too without being specifically told to do so.

Secondary Pump

My pumps add some heat to the water, so during the warmest parts of the day, I have the AC III turn this on and off in 15 minute and 1 hour 45 minute cycles - on for a little while, then off for almost two hours.

Air Pump

Kind of a waste of a control slot really, as I usually leave it on all the time. But the option to control it is there if I need it.

Drain Solenoid

Each night the AC III turns this on three times for about an hour. In my plumbing diagram you can see where this will slowly drain water from the tank. This solenoid is normally-closed (NC) so if I lose power, no water is lost.

Fill Solenoid

After each drain cycle, the AC III turns this solenoid on to fill the tank. Again, check the plumbing diagram. The water is filtered for chlorine and particulates. And like the drain solenoid, if I lose power this shuts off. No power, no AC III controlling it, no tank filling.

CO2 Solenoid

The AC III is also a pH controller. So it has a pH probe plugged into it (see top of diagram). Based on the detected pH of the water, it turns the CO2 on and off, keeping the tank pretty close to my defined sweet spot for CO2 ppm all the time. And it also prevents end-of-tank-dumps, if you are familiar with those.

UV Filter

I fluctuate between loving this and thinking it masks problems. So sometimes it’s on all the time. Sometimes it’s on only a little, and sometimes none. Either way, it’s controlled.

Heaters 1,2 &3

The AC III is also a temperature controller, and I let it control the heaters. There is a temperature probe connected to the AC III (see top of diagram). When the temp gets a shade too cold, the 1^st heater kicks in. If it gets ½ degree colder than that the second heater kicks in. And in the winter time when my fill cycle kicks in at night - I live in New England - the water is cold, and it drops a full degree less than optimal temp, and the 3^rd heater kicks in. Just as the AC III knows length of day depending on season, it understands seasonal temperature fluctuations. It’s probably unnecessary, but rather than just setting it at a particular optimal temperature, I let it float up and down a degree or two over the months, depending on time of year. The heaters themselves have thermostats on them (most do), and I have them set for a little warmer than the the warmest the AC III will ever heat that water. That way, if something happens to the AC III, they still will shut off before it gets too warm. And no one heater can over heat the tank, so a single one getting stuck in the on position is a problem - should it ever happen - but not a crisis.

Fertilizer Pumps 1, 2, & 3

The AC III turns on peristaltic fert pumps as needed, for the programmed duration. See my plumbing diagram for more info on these.

Other Devices:

Some things in my stand are not controlled by the AC III, but work with it.

IO Breakout Box

This Neptune Systems expansion device allows non-AC III switches to be detected by the AC III.

Contact “Feed” Switch

This is a simple switch (little Radio Shack SPST contact variety) that I’ve got mounted to my stand door. It is connected by two thin wires to the IO Breakout Box, which is connected to the AC III. So if I hit the switche’s button - temporarily closing the circuit - the AC III detects it. I’ve got the AC III programmed to shut the two water pumps down for 10 minutes if that circuit is closed. So when I want to feed my fish without also scattering food all over the plants, I just tap that switch. The pumps shut down for ten minutes and then resume normal operation. A simple device that greatly reduces uneaten food in the tank.

Liquid Level Pressure Sensing Switch

This is just like the Contact “Feed” Switch, in that it is connected to the AC III the same way, and the AC III knows when the circuit is closed. But in the case of this switch - a World Magnetics PSF102 - it is plumbed to the bottom of the tank (see plumbing diagram) and can detect the height of the water column. It does not close the circuit - turn on - until the water reaches what I’ve set as maximum height. That is set with a little trim knob on the switch itself. When the AC III is filling the tank at night, and the water reaches that maximum height, the switch closes the circuit; the AC III detects it and is programmed to shut the Fill Solenoid off - to stop filling immediately. Even though the AC III might think it’s got a few more minutes left in the time it’s supposed to keep the Fill Solenoid on, if the Liquid Level Pressure Sensing Switch turns on, the fill process stops. And my floors stay dry! Never fails.

WiFi Access Point

As I indicated before, the AC III can be controlled by a little web site that is hosted right on the AC III. But you’ve got to have a network connection to it. I’ve got a small home network, and I could have just run an Ethernet cable to the AC III, and that would work just fine. But I didn’t want another cable running into the stand, so I connected it to a Linksys Access Point. That connects to my home wireless network, and thus connects to any device on my home network - wired or wireless. So I usually sit down at my PC to make changes to the AC III’s controls through the web interface. But I can do it on my iPhone’s web browser too. It would be possible to make the AC III’s web site available on the Internet, so I could control the stand anywhere in the world (that has Internet connectivity). But that requires getting Dynamic DNS (DDNS) up an working for my router, and I don’t want to be bothered. Many of you will know what I’m talking about. And if you don’t - bottom line, it can be done, but it’s a little bit of a PITA, and kludgy IMO.

Exceptions

The drawing is reasonably accurate. But not perfect. There are three aspects in my actual wiring that are not shown… to keep the diagram simple.

Plug-Switches

Sometimes you want something just turned on or off, independent of the AC III’s programming. The AC III calls this manual mode, but you have to go to a web browser, or mess around with the little buttons on the AC III (which I hate) to do that. Kind of a PITA if you just want to turn a pump off for a second. So I got some little devices - I’ll call plug-switches for lack of a better name - from Home Depot. It’s just an A/C socket with a rocker switch on top, and a plug in back. It’s one solid little plastic piece that you plug a controlled device (like a pump) into instead of directly into a DC8. Then you plug the little plug-switch into the DC8. So when you want to turn something off momentarily, just hit the rocker switch. Easier than buttons and more immediately gratifying than going to a web browser.

Stand Light Switch

The left side stand light A/C cord has a little Radio Shack SPDT contact switch that I wired into it. The switch is mounted just under the left side stand door. So when the door is opened, the light turns on. Simple. All of the electronics are mounted on the left side of the stand. So I get light when I need it - automatically.

Socket Expansion kit

The older DC8’s - like mine - have a design flaw. It’s been corrected in current models, but these cannot turn a device off if its current is too low. One of my fert pumps draws very little current, so the DC8 can turn it on, but not off. A recipe for disaster! Fortunately there is an easy solution - the Neptune Systems Socket Expansion kit. This is like a little miniature 2-socket power strip. It plugs into the DC8 and into the normal power strip. It senses when the DC8 has turned it on or off, and draws power from the power strip as needed. And my fert pump is plugged into that. And just in case you noticed… yes, that takes more sockets on the power strip than I’m showing. My diagram drawing tool only has an 8-plug strip. My power strip has ten.

Fertilizer Pump 3

This is not actually installed. It’s sitting on a shelf, waiting to be bolted in if I ever need it. But it is planned in - the plumbing and electrical is ready - so it will be easy.

Conclusion

With all this planning, there is one MAJOR mistake in this wiring. Have you seen it? My powerstrip is not plugged into a GFI outlet! I forgot about GFI as I was setting up the stand, and with 180g of water over it, I’m not exactly able to slide the stand out to install a GFI plug now. So I bought a big, cranking 15 amp GFI cord. I plugged the powerstrip into the GFI cord, and the GFI cord into the wall socket. But every time the HQI lights turn on the d*mn thing trips. That’s no good. I’m not sure if I’m running into an amperage problem, or something else. HQI ballasts can put out some funky line noise. So this is an area that I’m going to have to research because I really need to get GFI on that circuit.

With the exception that one major oversight, this all works very well. If I lose power, the AC III recovers very gracefully. I never exceed the capacity of our home wiring, and it all works like a charm. I hope this example is helpful to you in your own planning exercises. Setting it up was certainly fun for me!