Wildlife and the greenhouse aquaponics setup -- Precautions

About 1 week after the picture here was taken, Seed Bed, the picture below was the view of that bed.  This was from a visit from either a raccoon or a large opossum.  All the plants died except for the cee gwa.

This is the bed after I "fixed" it.  It was completely trashed. The creature dug through it harvesting snails that were growing in the media.  I suspect it was a raccoon because it was strong enough to pull unglued pipes that were pressure fit.  It completely scrapped my flood and drain piping.  I found out about the visit during a remote camera viewing, I noticed the bed was overflowing in water.  Since the drain system was foiled by the creature the water overflowed from this bed.  It is the only bed that the overflow doesn't fill into another bed -- so it effectively drained my water to a failsafe level I have (otherwise my fish would be gone also).

In order to minimize this disruption or worse, fish kill, you need to take some precautions. Steps to consider:
* first by following the construction techniques of the greenhouse series, Gazebo-to-Greenhouse, you get a significant lead because wildlife do not attack through the styrofoam.  Now this could be the variety of foam I have used (see pictures in the blog), or maybe it is the creatures in my area (doubtful).  -- it took two years for this first large creature to breach the walls -- and they did it by realizing they could climb an adjacent pear tree and come in through the open "window" area
* it is key to cover your fish tank -- the breach by a raccoon would have been much worse if it had gotten to the fish in my tank

* on evidence of visitation, sprinkling of hot chillie powder can be used to dissuade calls -- also hanging a sachel of bloodmeal may be helpful  -- here you see how I used the chillie powder around the base of the outside greenhouse including the door entrance and on the top of the styrofoam walls.  Chillie powder on the outside will only be good until the first rainfall.

* if you have a particularly bad situation with visiting animals, you may also consider using galvanized or insulated chicken wire on the window area -- this has the added advantage of providing a growing mesh for your creeping vegetables -- I have plastic insulated chicken wire that I may install if the problem returns. The chicken wire can also be used on the inside behind the styrofoam wall panels if you have creatures that are not shy about tearing the foam -- if really bad, or you don't care too much about aesthetics, you may consider putting the wire on the outside.

* once you have determined the type of rodent or creature that is visiting you, you can also place traps -- if you worry about this, consider that while rodents will eat excess food that may spill around the place, they will also nest and/or do additional damage in pursuing additional food -- this happened to me in a rat that ate through my fish food feeder looking for additional food -- the hole added more food to the fish tank and was the cause of fishkill during one of my trips away -- my raccoon/opossum problem above was alleviated by using the traps shown -- the small mouse traps triggered but didn't do anything, but the larger black rat trap caught the creature, likely it's leg -- it got out and away but it did get a good dose of chillie power and likely a decent scratch from the trap before it freed itself -- didn't have problems after that.

Benefits of Vermiculite Growth Media for Separating Seedlings

Two of my aquaponics vegetable grow beds have a top layer of vermiculite.  I have detailed this in earlier postings. [Grow-beds-and-media-stackup.]

Some vegetables are very sensitive to root disturbance.  An example of this are pepper plants and specifically bell peppers.  Normally, to cover less than 100% germination, a gardener will plant 2 or more seeds (depending on expected germination rates) for every seedling desired.  When the seedlings are at their first true leaf you would cut off (kill) the less desired seedlings in a bunch to prevent disturbing the roots of the chosen seedling.

I found that vermiculite does not hold to the fine roots of seedlings. What I have been able to do then is to gently pull seedlings apart from the vermiculite and place them in another spot (making a hole for them with my finger).  The ones remaining do not get disturbed, and the transplanted one continues to grow also.  I did this first with tomatoe seedlings that had reached their first true leaf.  Tomatoes are hardy plants anyway.  But after that, I successfully did it with bell pepper seedlings.

This is a picture of seedlings in a bed of vermiculite. The red circled ones have been transplanted and doing fine after 3 days.  Note the coir pots for some of the seedlings.  These are meant to be transplanted into other beds. Since it is all soil-less I can even put them into the hydroton beds.

This is growth after 11 days total.  Note the transplants are doing fine. If you lift transplants when they are bigger, you need to be do it more slowly and gently as they have more rootlets developed.  I separated the two larger peppers on the left side just after taking this picture, and the one pulled successfully with vermiculite attached to its rootball.

Remote Wi-Fi Monitoring, Part 2

This is a continuation of the post, remote-wi-fi-monitoring-of-your-setup.  This entry will discuss accessing the video feed from the internet (not from your home network).

Once you have the system running per the first post instructions, you need to go and register with either www.no-ip.com or www.dyn.com.  I used no-ip.

Follow the instructions given here, http://www.youtube.com/watch?v=iHTxuYa3Kzo

After that, I had to update the firmware and web gui on my FosCAM in order to view the video on my smartphone (Android) via 3G while travelling.

I was able to use port 80 for the port forwarding in my router.  I did configure my router and the FOSCAM for my no-ip account (I will have to wait a month to see if doing both will cause a problem).

When accessing your remote host name -- the name you registered at no-ip.com and what you use on your browser to access the camera -- brings you directly to the camera.  Thus when you are asked for a username and password, that is the camera asking -- not your router, not no-ip.  Be careful here as there are different configuration pages, and if you don't keep it straight, then you will enter the wrong password and think your setup is not working.

So, in summary:

1. connect Foscam to ethernet and program it the first time
2. power off the camera, disconnect ethernet and power on again, and verify it connects to your wi-fi
3. create an account at a DDNS site (eg. www.no-ip.com) and register a host name
4. enter the config page of your wi-fi router and do the next router steps
5. [router] set the IP address of the Foscam to either static and one you choose or fixed at current
6. [router] set the port forwarding address to be TCP port 80 and the IP address of the Foscam
7. [router], optional, set the DDNS settings to your DDNS provider and account
8. [camera], set the DDNS settings on Foscam to your DDNS provider and account
9. [camera], optional, turn upnp on (should be supported and on at router also)
10. Wait up to 4 hours if you used no-ip for routing tables to be updated
11. Turn wi-fi off on your 3G smartphone, and go to your hostname.no-ip.biz in a browser
12. at this point you should get the login page of the Foscam.

View of Foscam access page from remote internet access (after login).

You can see the feed here:

http://wolfenhawke.no-ip.biz

username: visitor

password: marksgreenh

Remote Wi-Fi Monitoring of Your Setup

I have a rodent eating through the plastic on my auto feeder.  This plastic was the extension I attached and not a manufacturers accessory.  The caused a hole that forced an overfeed and a minor foiled water situation.  In order to get an appropriate trap I used the opportunity to configure a FOSCAM Fi8910W wireless camera I had. After seeing a small rat last night, I set some appropriate traps around the feeder and also covered the feed extension with a $5 aluminum vent pipe.

The system works well.  I am running 802.11b/g about 20m from my access point inside the house. Once I get the rodent taken care of, I will configure the angle of the camera so that I can view the condition of the fish tank water.  This way I can see if it is getting fouled.

The setup currently allows me to control (360 degree motion and up/down) the camera, record, and view from my desktop as well as simultaneously from a smartphone.  Setup was a breeze.  I recommend viewing the following for instruction:
http://www.youtube.com/watch?v=2xKu4uZtt3M

I use an Android, and the apps I use for viewing and controlling the camera are "IP Cam Remote" (free) and "IP Cam Viewer Basic" (free).

Using this instruction, you can view and control the camera from outside your local area network.  That is while travelling and through the internet:
http://www.youtube.com/watch?v=iHTxuYa3Kzo

View of feeder through my phone and IP Cam Remote.

The FOSCAM camera is here:

See Part 2 of this blog entry here, remote-wi-fi-monitoring-part-2

Aquaponics Failsafe Design

Failures happen.  It's part of life. Failsafes in your aqauponics setup are design considerations to provide safety and some level of protection (assets, fish, your own life) should things go wrong.  I will discuss a few precautions and their logic here.

Firstly, and most important is for the electrical feed in your setup.  This must be protected with a GFI plug.  You are dealing with water, many electrical appliances, and mains level electricity.  Either your feed should be from a GFI protected plug (shown), breaker, or extension.  The GFI will trip the electrical circuit should a   current be detected on the ground line (the start of a fault).

Secondly, should have an overall water circulation failure plan.  You can have the following failures, and I have listed my safety mechanisms:
1. grow bed drain failure (clogging) // overflow mechanism
2. sludge separator outflow failure (clogging) // overflow mechanism
3. water loss (either 1,2 above or pipe failure) // minimum water level in fish grow tanks
4. water in greenhouse // drain capability


My safety mechanisms are implemented as follows.

The overflow mechanism on the grow beds are either a drain to an adjacent grow bed, and/or an overflow directly back into the grow bed.

 bed to bed overflow allowance

over flow pipe on my sludge separator (the unconnected pipe on the left -- it is normally connected with a hose directly back to the fish tanks

 green overflow pipe directly to fish tank

The minimum water level in the fish tanks are provided by having the pump not be able to pump the tank dry.   My pumps are set to draw air at about a 6 inches (15cm) of water.  You do this by raising the pump at the bottom of the tank or situating it so it's input will hit air at your desired depth. This is important so that if you do get a pipe failure, your pump will not eventually empty your tank and kill your fish.

When you build your greenhouse or aquaponics enclosure, keep in mind you are dealing with water.  There will be times you want to empty your tank, have accidental spills, have accidental overfills, and other reasons why you will have water on the floor. Don't worry.  And don't make your walls waterproof sealed at the seam to the floor -- this will allow the water to escape.  If you did caulk or otherwise seal your wall seams, open a few water channels around the perimeter.

Third you need to have protection for overfeeding.  I have had the most trouble with inconsistent feeding.  This could be for a number of reasons and I have not determined the root cause.  The solution for this is to feed minimal amounts with your auto feeder.  I then manually top the feeding so that I can control it. What does this mean?  If I am travelling, I set my auto feeder to only feed once a day (in the afternoon).  I then feed the fish myself up to two more times during the day (morning and evening).  The fish survive fine with the single feeding.

Fourth, you need to have precautions on your air hoses.  This is to prevent water back pressure from returning along the air feeder lines and flooding your air pumps.  The precautions taken here are two.  First, and ideally you place the air pumps above the water level in your fish tanks.  Sometimes this is not possible.  If not, then the two methods applicable are to use one way air valves on the lines (of limited usefulness but part of the strategy), and a looping of the line (here you can also take the line first above the water level, but due to vacuum affects this alone will not prevent back feed). Even using these precautions note that a power failure in my home one day caused water backup into one air pump that caused a leak and, fortunately, triggered my GFI extension -- otherwise I would have stepped into a puddle of live power when trying to find out where the water was coming from.

In the future I want to connect the feeder, pump and a camera of my setup to the internet.  This will allow me full control while travelling.

Starting Seeds in Aquaponics Beds

Starting seeds for your aquaponics grow beds depends on the substrate you are using.  See this entry for options.  If you use vermiculite on the upper layer, you can just spread small seed on the surface and cover with a thin layer of more vermiculite.  Larger seeds can just be embedded in the vermiculite.  If you are using Hydroton, you can also embed larger seeds like beans just under the top layer.

For small seeds in Hydroton, or for more controlled planting in any media I prefer to use coconut husk pots with a vermiculite media.  I can germinate the seed either indoors or in the greenhouse, and then put the entire pot into the grow bed when ready.  This can be used in any media grow bed, including Hydroton.

The benefit of this technique is that you are not introducing organisms into your ecosystem that may be present in regular soil, you have control over the planting, and you can germinate the seed in optimum conditions for the appropriate seed.

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.

Automated IOT Greenhouse Sensor Reading

I am using an AirQualityEgg unit in my greenhouse to monitor temperature and humidity.  It also provides readings of CO and NO2.  I will setup another NO2 sensor closer to the water -- then see if there is a correlation between water nitrates and NO2 readings on the sensor.

You can get sensors from here, http://www.wickeddevice.com/

You can see my readings here, https://cosm.com/feeds/96569

You can get more info here, http://airqualityegg.com

Disclaimer: the sensors are not temperature corrected so you will see relative humidity go over 100%. Also, the readings at cosm include the raw sensor readings as well as the calculated information (not my doing - this is provided as part of the airqualityeggs).

Food for Tilapia

There are several options for feeding your tilapia depending on the size of your operation and the format of your grow environment.  This entry will focus on systems that have the fish in enclosed tanks.  This is as would be found in a city backyard system.  For reference, the use of large outdoor ponds is a different system that has other options.

General feeding issues.
You want to feed your fish for maximum growth and least waste.
Your fish can go with less food or no food for a couple days.
It is better to underfeed than overfeed when you will be away from your setup.  Overfeeding will lead to water fouling and fish kill.
Feeding your fish too much will result in undigested food travelling through their system, and inefficiency.

Starting:
If you are just starting; you have "started" your tanks and you are awaiting the delivery of your fingerlings; these are good places to get food:
http://premiumfishfood.com/
http://jimsfish.webs.com/fishfood.htm

Once you are going, you can experiment with different foods.  You can grow your own algae, make your own food or even use kitchen scraps.  Be slow in scraps you put into your tank to ensure you don't foul the water (eg. oily muffins are bad, bread can be good if used in moderation, raw vegetables can be good).  I found tofu to be a welcome food by the fish.

Ongoing and Recipe for your own food:
Purchased bulk food:
A good, reasonably priced food for your grow tanks is Purina Game Chow.  This is available locally at Tractor Supply Company.  It is variably sized and works well with both my auto feeders.

Tofu:
Tofu can easily be made at home. The most difficult part is making soy milk, but you can do this easily now with "soy milk cookers".
An example of a good maker is here,
SoyJoy Soymilk maker
Once you have made soymilk, you add a coagulant (calcium sulfite, or magnesium chloride) put in a press to remove excess water.  You can get food grade ingredients from http://www.soymilkmaker.com/order.html

Further instructions are here,
http://www.soymilkmaker.com/making_tofu.html

Cream of Wheat Cakes:
While I was investigating making my own tofu, and pondering the coagulants used in that process, I began experimenting with alternate recipes.  What I settled on and use regularly is the following. It came from the thought of making tofu, but instead uses other readily available ingredients.
1 cup instant Cream of Wheat
1 cup of medium burr ground soy beans
1/2 cup of ground corn meal
1/2 cup of finely cut dry seaweed
Begin making the instant cream of wheat per the package instructions.  Immediately after pouring in the cream of wheat, also add the ground soy beans, corn meal and dry seaweed.  Continuously stir so it remains smooth and does not burn.  Once the mixture begins to thicken turn off heat and cool for about 10 minutes (until still able to pour, or scoop).  I scoop the mixture into used tofu tubs with a spatula, pressing as I go, and then allow to further cool.  Cover with plastic wrap and place in refrigerator.  To use, cut rows and columns into block so that you can remove a square column and feed to tilapia.

Automatic feeding:
I use two types of auto feeders.  I use smaller units for my 55gal and 110gal tanks, and a larger unit for my 300gal outdoor setup.  Both feeders dispense 2-3.5mm circular pellet food (the Purina Fish Chow).

For my indoor tanks I use an Eheim Air Feeder.  These provide about a week of capacity and are reliable. I have a complete review here,
Amazon Review
Purchase from Amazon

For my outdoor grow out tank I use a Super-Feeder ASF-1 unit. I have modified my unit with an extra carrier to hold a little more than 1 week of food.
Super-Feeder Fish Feeder

Reference:
http://seagrant.uconn.edu/whatwedo/aquaculture/pdf/ncrac114_tilapia.pdf
Aquaponic Gardening by Sylvia Bernstein

Aquaponics:fouling water and other problems

Problems to be encountered in Aquaponics systems:
* predators: raccoons, opossums, they will eat your fish or destroy your grow beds looking for snails
    --> mechanically protect: cover fish tanks, enclose system
    --> simple styrofoam has shielded my system from these predators, though they did cut through my plastic door before I put foam on it also

* sludge fouling your piping and grow beds
    --> use a sludge separator: http://wolfenhawke.blogspot.com/2012/09/aquaponics-sludge-separator-update.html

* water fouled: this could be for any number of reasons, but most likely it will occur from overfeeding.  This can happen accidently due variations in an auto feeder
    --> turn off all feeding until water clears, don't worry, your fish can survive days without food
    --> if you see excess floating food, remove it
    --> if possible replace at least half of your water, but don't fret it if you cannot replace
    --> if you are using a timer on your water pump, bypass it so it is running 24/7
    --> run the system continuously until the water clears -- it will, then restart normal operation

* mysterious fishkill:  your fish are dying but the water is not cloudy
    --> this is rare for tilapia farming
    --> check your chemical levels
    --> check for dead fish fouling the water
    --> check the tank temperature -- sometimes heater elements will fail on
    --> check for water getting too cold -- temps lower than 55F are bad for Tilapia
    --> proceed similar to water fouled actions above: but on chemical imbalance, you will also need to investigate -- this could happen if you didn't "start the fish tank" and you put a lot of fish in at once, see http://wolfenhawke.blogspot.com/2012/10/starting-fish-tanks.html

 

Starting the Fish Tanks

First of all, a little primer on fish tanks.  They are an ecosystem creating a nitrogen cycle.  The fish eat food and expel nitrogen and feces which decompose and create more nitrogen.  There are two types of bacteria that live in a healthy fish tank that convert the nitrogen first to nitrites and then to nitrates.  Too much nitrogen or nitrite in the water will kill fish.

The filter in most fish tanks does a little bit of mechanical filtering, but it's primary purpose is to house the bacteria that is essential for the nitrogen cycle.  Thus if you thoroughly wash your filter every week because your water is getting cloudy, then you are in a constant wash cycle and are not getting your fish tank where it needs to be for your fish to be healthy.

You can read more here:
http://www.diyaquaponics.info/bacteria.html
http://fins.actwin.com/mirror/begin-cycling.html
http://www.algone.com/articles/aquarium-filtration/nitrogen-cycle

Nitrates are readily absorbed by plants for their nutrient uptake. This is the lynch pin in making aquaponics a self sustaining ecosystem.

I started my aquaponics tanks using clear ammonia and putting some extra operational filters from my indoor fish tanks into the aquaponics tanks (for bacteria transfer).

Monitoring Aquaponic Grow Bed Water Levels

With ebb and flow water systems, it is useful to monitor your water level under the surface of your grow media.  This is a simple but effective method do that.

As you are filling media into your bed, put a length of 1.5" PVC pipe in the bed vertically in the media.  Allow the top to protrude above the media surface by a good 2 inches (5cm) at least.  If you are using fine media, it would be good to attach some fiberglass screening with plastic lock ties at the bottom of the pipe.

Now make the indicator using a straw and a piece of styrofoam that is smaller than the diameter of the PVC pipe.  Say about 1.5cm in width.

 Picture showing styrofoam with straw embedded.  Note the graduations marked on the straw.  This is long because I use deep grow beds in my setup.

Picture showing the level meter in operation.  Water filling the grow bed is causing the indicator to rise.

Salads with Ebb and Flow? YES!!

In aquaponics systems, salad greens are normally grown in a flow or flood system with the roots continuously in running water.  I have a deep bed ebb and flow system and recently populated one bed with mesclun salad mix seed.  I used the vermiculite bed for the salad greens.  Please see http://wolfenhawke.blogspot.com/2012/10/aquaponics-grow-beds-and-media-stackup.html for various media stackups.  Seeds were just spread on top of the fresh vermiculite.

The following picture is a successful yield offered by this method.

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.

Single Pump Aquaponics System Design

I use an architecture in my aquaponics setup that requires a single pump per fish tank used.  This minimizes electricity and vastly reduces the complexity of the control system.  The water is pumped to my sludge separator design (see blog for details) which is at the highest location in the system.  Gravity is then used to move the water from the separator to the grow beds and back to the fish tank.  Using more than one fish tank in the same system requires balancing the effluent water from the grow beds and this will be addressed in another article.

The schematic of the setup is shown below:

The fish tank is shown below:

 













The sludge separator is shown here.  The pipe on the right is the influence. The pipe protruding from the front is the overflow back to the fish tank (a safety measure).











Here the piping is shown from the grow beds (3/4") to the collector (2") which returns the cleaned effluent back to the fish tank.

Since I use flood and drain as my water distribution, I could technically just keep the water pump running. I use drains on the side of the grow beds.  This side draining is much less efficient than bottom draining and what happens is that the water slows down in draining as it gets to the bottom of the bed.  This causes an equilibrium to be reached if the water pump is left on all the time.  At equilibrium the water is about 1/3 depth in the grow beds at all times.  I alleviate this problem, and save electricity to boot, by putting my water pump on a timer that runs 30minutes on, 30minutes off continuously.  This means I only pump half the time. It also allows the grow bed to get flooded and drain once per on/off cycle.

I have not had trouble with the side draining, but it does take a little tuning of the bell siphon.  We will cover this siphon design on another article.

Aquaponics Grow Beds and Media Stackup

Aquaponics is the raising of fish (for food) and recirculating the water through grow beds to grow vegetables (for food).  The ammonia that increases in the water in the fish tank is converted to nitrite and nitrate through the same process that occurs in a successfully operating fish tank.  In a display fish tank, this conversion occurs in the media in your filter and other areas (under the sand).  It is important to note that your fish tank filter's primary purpose is providing the media for the nitrogen cycle bacteria to thrive.  In aquaponics, this media is the material used to grow the vegetables.   The benefit of this is that the vegetation gets the nitrates they require directly as part of reducing the poisons in the fish water.  Thus you get a closed nitrogen cycle system.

On the post, Freeland-fp100-as-aquaponics-growbeds  I noted the Freeland bins that I use for my deep root grow beds.  On this post I will describe the stackup I use for the media.  The pictures below show a bed with hydroton as the top layer and one with vermiculite as the top layer.




The beds after being cut are 20" deep.  The bottom 6" are washed 3/4" gravel.  There is a long air stone buried in the bed at this point.  This is optional to have, but I wanted to inject air here to prevent any anaerobic bacterial action here.  A summary of the stackups I use is drawn below.

In some beds, I use Hydroton for the whole top layer (about 6" total depth).  In some I use about 4" of Hydroton and 4" of vermiculite.

The reason for the vermiculite is for seeding directly and for a variety of grow media depending on plant preferences.  Fine seeds work very well directly in the vermiculite.  I have had success with mixed salad green seeds, as well as tomato and cee gwa in the vermiculite.  I have had success with cee gwa directly in hydroton also.  In general for the hydroton beds, I start seeds in coconut husk pots filled with vermiculite.

The vermiculite really encourages robust root growth.  When harvesting often the top 3" of vermiculite is saturated with root (especially when growing tomatoe) and this must be disposed of and replaced with fresh material.  Below is a photo of vermiculite saturated with tomato root.  Also is a photo of cee gwa roots that were grown in hydroton.

Salad growing in a vermiculite bed:

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).

Don't Bother with Over-wintered Tomatoe Plants

On an earlier post I noted that my tomatoe plant from last year was growing well in the greenhouse.  The plant continued to grow very well and did a great job as an aquaponics water filter, but it was a complete failure as a tomatoe factory.  I removed the plant from the grow bed several weeks with nary a tomatoe harvested.  The following pictures show the size the plant got to (yes, that is a single plant) and the size of the stalks once removed from the planter.

Conclusion: don't bother with your tomatoe plants that survive past the first year.  Plant new ones.

On a related topic, overwintered bell peppers do very well continuing to produce.  You can see the bell pepper plants to the left on the photo of the tomatoe stalk photo.

Gazebo to Greenhouse: Roofing

The roof of the greenhouse is made of Solexx XP paneling.  Note, the roof elevator frame is removed.  This is a piece of metal framing on some gazebos that allows dual layer canvas roofing that provides air venting.  With this removed the roof frame is a single level, though I had 4 protrusions from the elevator frame.  I tried turning one of the original roof frames upside down so the protrusions wouldn't get in the way of the paneling, but the frame is not suited for that.  I got one to work, and just left it.

The paneling is cut to appropriate lengths and then placed on top of the metal frame roof.  Some geometric planning, and careful measurement is required here for a minimally seamed solution.  I allowed for spaces between my seams and covered them with pool covering insulation.  The XP panels I used are dual pane with an air insulator pocket in between. These are stiff enough that they can be attached to the metal greenhouse frame with zip ties.

The insulation I used for the seams proved to not be very UV resistant, so I am updating the seams with the UV greenhouse plastic used for the upper walls.

Other posts in this series:
Pictures More Pictures
Start
Insulating and Doorway
Upper Walls
Door
Roofing

Gazebo to Greenhouse: Update: door

On an earlier post you saw the framing of the door for the greenhouse.  Here is a picture of the finished door.

This is wrapped in pool insulating plastic which is actually not very UV tolerant, but it works fine for the door.  There is an interesting point I would like to make.  The greenhouse is really framed on the lower half with about 3/4" foam.  

The door is just plastic wrap.  I have racoons and opossums in my neighbourhood -- not many but they are here.  For some reason they don't bother trying to get through the foam -- maybe it's the foil cover on the outside? Don't know. They can obviously smell the slight fishy water that is in the greenhouse.  Well after about 8 months I did have infiltration of the greenhouse -- through the door -- they scraped back the plastic cover on the bottom and walked right in at night.  Only damage thankfully was rummaging through one of my planter bins for snails -- the creature did not attempt to get into my covered fish tank.

I put some of the insulating foam on the lower half of the door to dissuade the critters, and just for insurance also attached 1/4" wood on the outside bottom of the door -- that has kept the kritters away.

The door uses a gate latch system.











An update picture is shown here also of my 2012 tomatoe and Cee Gwa (both started from seed directly in this bin -- this is the seed starter bin).

Other posts in this series:
Pictures More Pictures
Start
Insulating and Doorway
Upper Walls
Door
Roofing