MY Reefkeeper Lite Controller Installation (With Pictures)

csarkar001

New member
My new 125 gal tank is still under construction.

i'm starting this separate thread to document the installation of my RKL controller for my fish-only tank. this is my third RKL unit (the other two control my discus tank and my water changes for the discus). Hopefully, i can avoid some of the mistakes i made when installing the first two.

this installation will have a several standard features and a few custom ones:

Standard:

  1. Control, Monitor, and Alarm Temperature
  2. Provide a Timer for the Main Lighting; Turn off main lights if the temperature gets too hot
  3. Control Night Lights
  4. Monitor and alarm pH

Custom:

  1. Monitor and Alarm Sump Level; Turn off Sump Pump if water level is too low
  2. Use a manual switch to override the lights
  3. Use a second manual switch to turn on/off the lights inside my cabinet

Standby:

This mode will be used for water changes. During standby, the controller should, turn on the lights, shut off the sump pump, protien skimmer, and heater.
if standby is left on for more than 45 minutes, the system will automatically exit standby.
 
Last edited:
Reef Keeper Pictures

Reef Keeper Pictures

picture.php


What a mess! Hopefully, it will take less than a week to finish this install.

picture.php


Here is a picture of the input module. i'm going to install that first. For my application, i'm going to connect the iTemp probe, pH probe and both switches.

picture.php


This is a picture of one of the two controllable outlets. each one has four ports. the first and fourth receptacles can handle more current than the middle two.

picture.php


This is the display unit that will be mounted outside the cabinet.

picture.php


this is the iTemp temperature probe. it doesnt look like the itemp probes on my other two, older units. i think they may have gotten some complaints about the old one because this one looks a lot nicer.
 
Monitoring Water Level in the Sump

Monitoring Water Level in the Sump

No matter how careful i am, somehow, sometime, the water level in my sumps drop too low.

the RKL has a couple of switch ports (contact closures) on its SL-1 input module. i am going to hook up a float switch to one of these switch ports. the sump pump will be plugged into one of the controlled power outlets instead of directly into a wall outlet. when the float switch senses that the water level is too low, it will set an alarm which will turn off the sump pump.

i've done this once already with my automatic water changing system for my freshwater setup. over the past two years, it has already saved my pump twice.

As the previous poster suggested, this same setup can be used for ATO.

could you explain this?
 
Installing the Head End Unit

Installing the Head End Unit

The Head End Unit is the user interface and display:

picture.php


1. Drilled a 1/2" hole in my cabinet to feed the cable:

picture.php


2. Took a 3/8" x 1/2" rubber grommet and feed it over (with much difficulty) the RJ11 connector at the end of the head end unit cable. (You can get an assortment of 125 rubber grommets on eBay as a kit labeled ATD-362. I think ATD is the company).

picture.php


3. Inserted the grommet into the hole in my cabinet and feed the cable all the way into the cabinet.

picture.php


4. drilled two pilot holes (3/32") and screwed in the head end display on to the cabinet. Here is the finished product:

picture.php
 
Will be following this thread... I'm debating getting this unit for my next tank and want to see how you implement it. Looks good so far!
 
RKL versus Neptune

RKL versus Neptune

Thanks. Never used the alternative controller from Neptune but have only heard good things about it as well. suspect they are about equal.
 
Input Module Installation

Input Module Installation

Next, installed the input module inside the door frame of the cabinet. This may seem an odd choice but my space is limited inside my cabinet and i want to use every inch available.

picture.php


the big white tube on top of the unit is my cabinet light.

i hooked up the bus wires from the head end to the input module. i then attached the iTemp and pH probes and attached them with suction cups to the bottom of the sump:

picture.php


the last time i installed one of these probes, i made the mistake of depending on the suction cups to keep the probe in a fixed location. but over the course of several months, the suction cup came loose and the probe somehow managed to go visit my heater which was also located in the same sump. the pH probe then melted and had to be discarded.

this time, i have attached some small acrylic cubes to my sump using weldon-3. i take two such cubes, attach them to each other, offset slightly and then glue the item near one of the sump corners. this forms a bracket to hold the probe cable. here is a closeup:

picture.php


i bought the acrylic cubes and weldon-3 from tap plastics on line. still looking for a chain store in the north east that sells these products. please drop me a line if you know of any such.
 
Controllable Outlet Installation

Controllable Outlet Installation

After drilling two small pilot holes (3/32"), i installed the outlet module next to my power strip:

picture.php


for now, i think one outlet module should be enough for this tank. Here are the port assignments:

Port 1: heater
Port 2: protein skimmer
Port 3: night light (3 LEDs built into my retrofit kit)
Port 4: tank lights

ports 1 and 4 handle more current.

still considering hooking up the night light to the power strip, instead, and just leaving it on 24/7. anybody have an opinion on this?
 
Heater Installation

Heater Installation

Plugged a Finnex 500 Watt titanium heater into the controller (port #1) and laid the heater out horizontally on the floor of my sump.

picture.php


to accomodate this heater, i've programmed outlet port #1 on the RKL as a controller port with the iTemp probe as the device. The heater is programmed to come on when the temperature drops below 78 degrees F. Even though the RKL people recommend setting the hysteresis to 0.1 degree, i always set it to 0.5 degrees so that my heater will not keep going on and off frequently. thus, i expect my tank to remain between 77.5 degrees and 78.5 degrees.

also, if the sump ever goes dry, not only will my pump die, but the titanium heater will certainly fail as well if it is no longer fully submerged. so still have to put in a float switch to detect low water level and turn off these applicances, for some added insurance. still waiting for the float switch to come in the mail.
 
Last edited:
Installing Override Switch for the Tank Lights

Installing Override Switch for the Tank Lights

Most people keep the tank lights on for longer on the weekends and less on weekdays. i work from home and so am the opposite.

but my schedule is irregular; i often am home at odd times and want the tank lights on. however, it takes too many button presses on the RKL head end unit to override the lighting controls to turn the lights on at a moment's notice.

so i have decided to install a mechanical toggle switch for this function. (with my last tank setup, i used a 24-hour mechanical timer instead of a switch because i was worried about forgetting and leaving the lights on all night. but this time, i am going with a simple switch).

Here is a list of parts and tools needed for this switch installation:

  1. a simple round toggle switch
  2. RKL switch adaptor kit (this is wiring between the switch and the SL-1 input module; the SL-1 uses a molex connector for each switch port)
  3. two small pieces of heat shrink tubing
  4. a soldering iron and some solder
  5. a 3/4" spade drill bit and drill

Here is a picture of the toggle switch i used:

picture.php


it costs $3 at radio shack (catalog part number 275-015). i use a round switch because a round hole is much easier to drill.

i drilled a 3/4" hole in my cabinet where i want the switch mounted.

picture.php


i wired (soldered) the switch to the adaptor kit wiring and used heat shrink tubing to cover up the solder joints:

picture.php


Then, i inserted the switch in the hole and plugged in the molex connector into the SW A port of the controller's SL-1 module. Here is the completed assembly:

picture.php


will discuss how to program the RKL for this override function for the lights when we talk about installing the lights. but the overall idea is to program this switch to trigger an alarm and then use that alarm to turn the lights on.
 
Float Switch Placement

Float Switch Placement

almost made a big mistake in terms of where to install the float switch in my sump. my first thought was to mount it near the probes ...

... but i have not yet installed a protein skimmer. one of the posters on this forum said that a fixed water height is critical to efficient opperation of the skimmer. my sump does not come equipped with a baffle so i will have to install one. it is critical that the float switch be mounted after the baffle (to the right), close to my sump pump. otherwise, as the water level decreases, the pump will run dry before the chamber with the float switch.

picture.php


will probably try to build my own baffle soon after selecting a protein skimmer.
 
Float Switch Mounting

Float Switch Mounting

Thanks. if you have any thoughts on how the Elite model compares to the Lite that i am using, please post.

Here is the float switch which arrived in the mail today:

picture.php


i want to avoid drilling an unnecessary hole in my sump so i'm going to attach this float switch to an acrylic cube. i will mount the cube in the sump.

first, i drill a hole of diameter 15/64" (yes, it took me a few tries to figure out the right drill bit to use for this project), on a 1" acrylic cube that i purchased from tap plastics:

picture.php


notice the hole is cut well off center. this is important because the cube i am using is not as wide as the bracket supplied with the float switch. if i were to drill the hole in the center of the cube, the side of the cube would not make contact with the sump wall once the bracket is attached. this will be easier to see once i put up a picture of the finished product.

i then took some Weldon-16 and mounted this cube in my sump so that the hole is facing to the side:

picture.php


The cube should be oriented so that hole in the cube is far from the sump wall, not close to it. that will give the float switch bracket more room for mounting.


this was my first time using weldon-16. usually, i use weldon-3. but weldon-16 is more syrupy and much easier to work with. this glue takes 24 hours to set. so tomorrow, i will attach the float switch to the cube using the supplied plastic screw that comes with the float switch.

separately, i have attached the red-and-black wiring that comes with the float switch to the wire ends of the float switch. this wiring allows the float switch to be connected to the SL-1 input module on the RKL. i soldered the wires together and used heat shrink tubing to cover the solder joints. this is particularly important here because as the level of water in the sump rises, these soldered connections could be underwater in the sump.

RKL installation should be done tomorrow except for lighting which has yet to arrive in the mail.
 
Last edited:
Wired Float Switch

Wired Float Switch

Here is a shot of the float switch wired to connect to the SL-1:

picture.php


sealing/covering the solder joints with heat shrink tubing is important.

the red/white wiring and screws are all provided by the vendor when ordering the float switch.
 
Float Switch: Final Mounting and Testing

Float Switch: Final Mounting and Testing

Here is a shot of the float switch mounted in the sump on the acrylic cube:

picture.php


i plugged the molex connector into the SW B port of the SL-1 input module.

i programmed the float switch to Alarm #2, set to trigger when the value of the port goes below 0.5. when the switch is floating, the port value is normally 1.0. if the bob comes down (sump runs dry), the value goes to 0.0.

To test this float switch, i set the head end to display the value of SW B and then used my fingers to lower the bob on the float switch. the display changed value from 1.0 (normal) to 0.0 (alarm). In response to this alarm, the sump pump turned off as programmed.

Now only the lights and protein skimmer hookups remain.
 
Last edited:
Thanks for documenting your design -- creative uses of limited inputs and outputs make control systems work in he real world!
 
Thanks for this thread, it is very useful. Most people just show their units in a complete form making it difficult for some to see how they are used. I am would like to buy a unit but was not sure if it would be advantages for me, I am currently trying to automate my system, I just put a DIY ATO on.
 
Question regarding the "lights on" switch.

I understand how the switch can trigger an alarm event and then turn on the lights. I also understand how turning off the switch will turn off the lights. What happens, however, if the switch is on at a time that the lights would normally be turned on by the RKL -- and then you later turn it off?

In other words, assume the lights should normally come on at 9am. You flip on the switch early - at 8:45am. Then you flip the switch off at 9:30am. Does RKL know to still keep the lights on?
 
Back
Top