Internet of Things Alarm for Fouled Water in Aquaponics

My post, greenhouse-sensor-reading, noted an experiment to use the Sensor Egg to detect elevated levels of Nitrite/Nitrate in my aquaponics tank which are deadly to fish.  I am happy and sad to note that the experiment shows that this thesis seems valid.
The theory here is that elevated levels of these chemicals in the water may trigger the N02 sensor in the egg and show a reading which can be used as an alarm.
What I found in two occasions was that an imbalance caused by overfeeding caused fowling of the water and triggered elevated readings in the Egg.  If you look at 1-15-2013 and 1-27-2013, https://cosm.com/feeds/96569, you will see elevations.  The second elevation occurred while I was travelling on business, and due to the length of time before I checked on the tank, it resulted in fishkill which caused a loss of about 50lbs of fish.
While I am not sure of the accuracy of the NO2 calibration of the sensor unit, it is sufficient to use the relative value as a trigger.  I have the cosm feed set to tweet me should the value rise above 250PPB.
If you are setting up a new tank, then the Nitrates/Nitrites will be elevated while you are "starting" the tank.  Use this to set your high point on the sensor readings.  When your tank settles -- that should give the normal "safe" reading level.

Bell Siphoning for Aquaponics Grow Beds

Aquaponics systems use one of two water recirculation systems primarily.  One method is the "flood system", "flow system", or "constant flow" system.  This system runs the water continuously through the root systems of vegetables.  The other method is the "flood and drain" or "ebb and flow" system.  This system adds water to grow beds causing the water level to rise to just below the media surface, and then drains the water and repeats the process continuously.

Flow systems are good for salad green farming.  Flood and Drain systems are good for all types of vegetables but are a little more complex.

As you have seen from my setup schematic, http://wolfenhawke.blogspot.com/2012/10/single-pump-aquaponics-system-design.html, I use Flood and Drain in my system.  This is accomplished by using a bell siphon in the grow bed.  This apparatus does not use energy but counts on vacuum created in a sealed water system.  There is plenty of information on building your bell siphon.  One paper is available here, http://www.ctahr.hawaii.edu/oc/freepubs/pdf/BIO-10.pdf.

Since my grow beds had a drain plug on the side, I used this. I do not recommend going from the side as the setup is more complex to tune, but I am showing this for interest/information.  Certainly, you can setup your similar beds with the draining straight down.

As you can see, my internal standpipe makes a 90 degree bend which is non-standard.















After that the bell pipe is installed on the standpipe.  Note, one disadvantage with the 90 degree standpipe connection, is that the bell pipe cannot seal as far to the bottom.  The top of the cut at the bottom of the bell pipe determines the minimum level of water in the grow bed.  My bed will have about two inches of water always at the bottom.

After this stage, you can fill the planter with your media.  As you can see, one benefit I do have with the 90 degree install, is that I can tune the height of the water draining by turning the bell pipe and standpipe as a unit.  I had to do this on all my planters to get the desired height -- this is likely because I do not use "snorkels" on my bell pipe and the trapped air is compressing and affecting the rising water level.

Aquaponics Sludge Separator: Update

This is an update to this post: http://wolfenhawke.blogspot.com/2010/09/aquaponics-sludge-separator.html

In June my aquaponics water feed pipes started having a lot of sludge.  On inspection it turned out that the plexiglas wall had come loose from the sludge separator.  This was great evidence of how helpful this simple equipment was.  The loosening of the plexiglas was likely due to the expansion of the plastic bin when loaded with water causing stress on the sealant. 

The solution was to mechanically attach the plexiglas.  This was accomplished with the white rectangular implement shown on the top of the bin in the first photo.  Using these nylon items along with nylon screws ensured that no metal would be imparted into the aquaponic water system.  Any such fastening technique can be used -- I got these particular parts from Orchard Supply Company.

I did a modification to the original design at this time putting in a second bar at the influence that would cause the water to "roll" over it and onto the plexiglas.  The effect of this is material is improved sediment trapping in the first compartment.  Note the lengthened effluent pipe was removed eventually -- it did have the interesting affect though of allowing the depth of water in the second compartment to be set (due to the vacuum affect of water leaving).

$1 Aquaponics Water Polisher

I saw this $1 "Mini Trash Can" at a local OSH.  Couldn't resist the idea.  Simple.

The "trash can" has a lid that turns to lock.  This is the key. It allows the filter to be easily opened to replace the media.

Cut out a 1.5" hole in the lid and replace with 1.5" PVC pipe (suitable straight length or as shown with a 90degree elbow).  Next drill 1/4" holes (two rows) all around the bottom of the can.  Fill the can with polyester cotton.  Put the lid on and you are ready to attach your new filter to the water return on your tanks.

















Another implementation of a polisher is shown below.

Cheers.

Sludge Separator in Action

This is the implementation of the "Aquaponics Sludge Separator" design from my September, 2010 blog entry.  I simplified the design as follows:
* used a rubbermaid storage container instead of building square out of plexigla
* reduced baffle plates to 1 instead of 2
* reduced oxygenators to 1 on the baffle plate only
* did not implement the water feed "shelf"
* the drains were single orifice instead of a long feeder pipe

Parts used:
* rubbermaid container
* acrylic sheet from Tap Plastics
* 1" Uniseal connectors (www.aussieglobe.com)
* 1" PVC pipe
* 7" TopFin bubble Wall wand
* DAP Household Adhesive Sealant, 100% Silicone, food and aquarium safe

Special steps.  I used silicone glue to attach the acrylic baffle to the tub.  Ensure you sandpaper the tub well and clean off prior to applying the silicone or it will not attach.

There is no need to use silicone to seal the uniseals.  They work in place.

This is a picture of the build before installation and before I put on the overflow.

Cheers!

Update 2011:04:10 I am running this setup successfully with a 655GPH pump.  The intake and output is 1" pipe.  The output is gravity only and uses a 1m drop before going to the feeder pipe.  I am feeding 3 outputs of 3/4" PVC.  I will post the aquaponics setup in the future, but am considering how to add a second feeder tank -- I don't think this separator will handle another 655GPH input.

Aquaponics Sludge Separator

This is my design for a separator for use in an aquaponics system for the effluent from the fishtank before sending the water to the grow beds. The system is similar to a septic tank except that it uses aeration to prevent ammonia formation from additional decomposing of the sludge (in principal). I am intending on using a unit about 24cm x 36cm to handle the water from a 250gallon fish tank next summer. The small tubes are the aerator tubes. The large tubes are 1" PVC (with holes) to be used to drain collected sludge. Sets of tubes will be connected. This can be built with acrylic, or in rubbermaid tubs or even (for commercial sized uses) in waterproofed outdoor garden bench storage units.