Worms in Aquaponics?

Last week I was cleaning out one of the beds that uses a continuous flow technique.  The plants had become so overgrown that it was time to do some serious pruning.  Because I was removing so much of the top of the plants I thought it would be a good idea to prune the roots as well.  These Everglades tomato plants are so hardy and they really respond to this pruning technique.

The grow media in this particular bed was a base of pea sized gravel with about 2 inches of expanded clay (Hydroton) on the top.

When the bed was first set up, I put some earthworms in there just to see how they did.  The answer to that question is..... they did wonderful thank you very much!  The earthworms help break down solids from the fish tank and help keep your grow beds clean.  They also assist with "mineralization" which is a fancy term that means they convert their food to available nutrients for the plant roots.  If you read much about serious aquaponics then you will run across the use of worms, but not earthworms.

My earthworms didn't know that they were not the preferred worm for aquaponics.  Each time I dug up some roots to prune I came up with enormous earthworms!  Now I know many aquaponic enthusiasts are crazy for red wigglers for their worms, but I am liking earthworms.  The first and foremost reason is because earthworms are cheap.  They are already growing in our compost beds.  We don't have hardly any red wigglers in our compost.  Maybe they aren't indigenous to South Florida.  I don't know, I just know that if you want red wigglers you have to buy them.

Because our compost pile is fed with bunny manure, I purge the worms before putting them in the bed.  I don't want to introduce any e.coli from our furred friends into the aquaponic gardens. 

Purging the worms is easy, just put them in a small amount of moistened corn meal for a few hours and they will have the equivalent of terrible diarrhea and vomiting. It is gross when you look in and see all that black gunk in the cornmeal, but the worm is clean inside and out.

I just give them a quick rinse in some water from one of the fish tanks and then into the bed they go and boy do they grow!

I put just a few earthworms in there when I set up the bed with the tomatoes at the end of last summer and now it is full of earthworms.  I have been routinely adding worms to each new bed that we set up, but I haven't done much in the way of digging around to see how they were doing.  Out of sight out of mind is the way they have been operating.

So I say if you don't have some worms in your grow beds, get some.  You may not have to go any further than your compost pile.

So do you use worms in your aquaponics beds?

Octopus Slayer - Part 2

If you remember from a prior post last year, we made some changes to the large A-Frame NFT system that was being used over at the Together We Stand Aquaponic Gardens.  It had been designed with a manifold at the top to feed water individually at each tube and to drain each tube individually. It had so many hoses going so many directions we called it the "octopus".  Classic exacmple of over-engineering to solve a problem that didn't exist.

When I wrote about how we changed the water flow I mentioned that instead of black tubing, my hubby cut a garden hose to make the jumper from one tube to the next. It was easy, quick, and most importantly cheap!

After I posted this, several folks commented on this blog and other places about the wisdom of using a garden hose. There was quite a bit of concern about the safety of the water flowing through the garden hose and the possibility of leaching toxic chemicals.

Quite honestly, for as "smart" and evolved as we are supposed to be, it never occurred to us that the hose might taint the water.  Hubby and I  both grew up in a very hot and dry area of South Texas and drank lots of water from the hose as youngsters and teens. While it did have a funny taste, I just always guessed it was from the metal bib of the hose.  That and the fact that all the water in that town tasted like crud, no matter the source.  But when you are hot and thirsty you will drink what is available.  Of course, this was back in the 60's and 70's so we didn't know about things like bottled water back then

But this is a new century and we are evolved and enlightened!  So a few days ago, hubby decided that the garden hose should be replaced.  You spoke and he listened!

 This did require a trip to Home Depot, but it was only a few dollars and the result looks clean and works well.  I think fighting the crowd of Canadians in the parking lot and through the store on a Saturday (remember this is Hollywood Florida and it is January and in the mid-80's so all the snowbirds have landed) took longer and was more effort than making the actual change.  Here is the new set-up. 

Here is another view.

Nice huh?

But this gets me to thinking about all the things we did as kids that people never do now....or they don't allow their kids to do now.  Maybe it was because we were from a small-ish town, but we rode our bikes everywhere and got into everything. I don't know how we survived.

How about you?

Cycling A System - Should You Go Fish?

Aquaponic systems are closed loop systems that replicate the naturally occurring symbiotic relationship between plants and fish.  Fish provide nutrients for the plants and the plants clean the water for the fish.  Like all relationships, this one takes time to develop as well.

Whether you are designing your own system or looking to purchase a prefabricated system you should be aware that it will take some time for your system to function so that fish and plants are both healthy and growing.  The process of establishing this symbiotic relationship is referred to as "cycling".

You can cycle with fish or without fish.  The choice is yours.  Whether you cycle with fish or without fish, you will need to keep an eye on the water chemistry so go ahead and invest in a good water quality test kit.  These kits will allow you to test for pH, ammonia, nitrites, and nitrates.

I have cycled systems both ways and I prefer fishless cycling.  I will admit it:  I am a mushmellow.  It bothers me when fish die.  I feel like I am their steward and when they die I have failed them.  The truth is when you cycle with fish some fish are going to die.  During cycling there will be ammonia and nitrite spikes that will kill fish.  It is a natural part of establishing the system.  Even if they are just the cheap little feeder goldfish from the pet store, it hurts me when they die.  So I like to cycle without the fish.

In fishless cycling you add ammonia to the fish holding tank (that has no fish in it) in an amount sufficient to bring it up to 0.5 ppm.  You then test the water daily until levels fall back below 0.5.  You add ammonia again to bring it up to 0.5 and wait for it to drop.  After a week or two of this you will start to see some nitrites show up.  These are the nitrosomona bacteria that are establishing themselves in the system and will start to convert that ammonia to nitrites.   You should see a big spike in nitrites before the nitrates show up.  Once the nitrates show up that means you have nitro bacters growing in the system. These guys will take nitrite and convert it into nitrate.  Once this cycle is established you can safely add fish to the system. 

The amount of time it takes to cycle a system without fish can vary from 3 to 6 weeks.  Things that affect the cycle time period are water temperature and pH. Keep your water temperatures on the warm side and the pH in the neutral zone. Also, if you start cycling with water straight from the tap, it will have chlorine in it.  This chlorine is there to kill the unsafe bacteria in your drinking water.  It will also kill your nitrifying bacteria.  That means anytime you use straight tap water you are setting yourself back.  Luckily chlorine readily off-gasses and if you let your water stand for 24 hours the chlorine/chloramine will dissipate and you can safely use it in your aquaponic system.  This is especially true when you need to top off an existing system.

Cycling takes patience.  In the mean time, enjoy the plants that you put in your system.  You have to have plants for the cycle to be established, so plant some water loving plants.  Things like basil, mint, and tomato will do well in a system that is not cycled.  This is because they like water and the lack of nitrogen doesn't really bother them.  In fact, if nitrogen levels get too high, tomato plants will grow but not bloom!  Onions are also great plants for cycling. I've even cycled with petunias!

There is another method of fishless cycling that is mostly promoted by men. It is called "pee-ponics" and instead of adding pure ammonia from the store into the system, human urine (referred to as "hummonia") is added to the system.  Don't really understand why men want to pee into their aquaponic systems, but to each their own.

You can speed up cycling by inoculating your system with bacteria from a healthy system that is already established.  This can be done by taking water from the filter of a healthy system or simply taking water from a healthy system.  Be very careful when doing this.  If the system from which you take your water is not healthy, then you have just spread its disease to your system.  If you have one already cycled and well operating aquaponic system, then by all means harvest the bacteria from your existing system to jump-start your new system.

Lastly, you can go to a pet store that deals in aquariums and purchase bacteria in a bottle.  I am not a fan of this because it is pricey and honestly, how long can those bacteria live in a bottle?

How do you cycle?  I'd love to hear your experiences.

Why Round is Better All Around

Just because I haven't been blogging doesn't mean I haven't been busy.  It means I have been too busy to blog!

Here in South Florida, what every one else calls winter is what we call our growing season.  It is the only time when temperatures, humidity levels, and rainfall all fall back into levels that support hearty and healthy plant growth.

In our own aquaponic systems we have mints, onions, peppers, tomatoes, brussels sprouts, eggplant, arugula and endive chugging along.  In soil we have tomatoes and peppers.  Each and everyone has appeared to have had a very merry Christmas and are starting off the new year great.

Things weren't the same over at the Together We Stand gardens.  The aerator to the fish tanks gave up the ghost. Fish croaked (and these fish are tilapia not croakers - a totally different fish but I digress).  Ammonia levels spiked. Fish croaked.  Ammonia levels went higher.  Well you get the picture.  We were stuck in a closed loop of high ammonia levels and dead fish.  Significant water changes were only making a marginal difference.  We lost over 60 fish in one day!  At this rate, this aquaponic garden was not going to survive.  It was time for detective work.

We started with what we knew to be true.  Aeration had been restored.  Dissolved oxygen should not be the culprit. Even after a couple of 60% water changes ammonia levels continued to be off the charts. The fish were not being fed so they weren't making the ammonia and after removing the dead fish the levels did not come down.  There had to be something we were missing....and there was.

The fish tanks in use are designed with grooves on the inside for placing dividers.  The bottom of the tank is a series of three inverted pyramids.  This is supposed to allow the grower to divide the tank into three areas to separate fish of different sizes.  If you don't understand the description, here is a picture (which should be good for at least 1,000 words).

In reality what this actually does is provide a very deep area in which something like a dead fish can settle. Yes folks, that is what turned out to be the source of our ammonia problem.  After draining the tanks down  to about 25% we were able to see the 13 dead fish that had settled in those inverted pyramids.  When the aerator failed, not all the fish that died had floated. Some had settled and that was the source of the ammonia.  Once those areas were cleaned and the tanks refilled, the ammonia levels  went down and stayed down. I don't want to live those 2 days again.  But, with the mystery solved on the third day we were back on track. 

Dr. James Rakocy, the father of aquaponics has always advocated for round fish tanks.  You can't hide in the corners if there aren't any corners.  Now even though these tanks have radius corners at the edges, they still have corners of a sort on the bottom.  So to the adage that tanks should be round, lets add that they should have flat bottoms.

After all, how can your garden survive if the fish themselves can't survive?

Don't Overthink or Over Engineer Your Systems

It is so easy to get carried away with the physics involved in building your aquaponic grow systems that the  simple becomes unduly complex.  Complex is not good. Complex is rarely if ever easy to maintain. Try to avoid complex as much as possible.

If you think effort goes into designing a large system, just try to re-design a large system after all components are in place but not functioning as they should.  Implementing the re-design means that you have re-do all the previous hard work.  Not efficient use of time or energy.  If you and your garden want  to survive, you need to use your time and energy as efficiently as possible.

The following is a great case in point of over designing a system.  When the a frames for NFT (nutrient film technique) tubes were first designed and built for the Together We Stand project, the designer was greatly concerned that because the water was going to flow through 4 tubes before draining that all the nutrients would be absorbed by the plants on the top row and the plants in rows 2 through 4 would be nutrient starved.  So a complex manifold system was created and installed to give equal feed of the nutrient rich water into the top of the a-frame.  Truly a beautiful design as you can see from here.

Since each A-Frame has two sides, there was a manifold for each side of the frame.  Of course, this system over engineered a problem that didn't exist.  See, the nutrient levels at the top tube of an A-Frame are not significantly lower than the bottom tubes unless your system is extremely nutrient deficient. So, this overly complex design solved a problem that didn't exist.  However what it did do was utilize flow tubing that was so small you didn't get good water flow and it clogged constantly. In addition, since each tube was fed individually, it drained individually.  If you think that manifold was something, then check out this drain system

Looks like some kind of octopus, right?  In addition, note the use of clear tubing.  Well it was clear at the start I am sure.  But because the clear tubing allows sunlight to penetrate, algae growth was a constant problem and because of the design, 8 drain tubes needed to be cleaned on a regular basis.  All to solve a nutrient feed problem that doesn't exist!

The answer was to re-plumb the A-frame so that water enters in one location on each side of the frame and then feeds and drains each tube in sequence.  

So that anyone working on the system in the future will understand how it operates, each tube was marked at the feed and drain points and also with arrows indicating water flow.

 Note the use of dark tubing for the inlet feed tubing.  For the jumper lines between the tubes, in a stroke of genius my husband realized that garden hose would work perfectly and is certainly less expensive than other hosing. 

Since there is now only 1 drain for each side of the frame, only 2 drains are necessary.  That means we can slay the octopus and the task associated with keeping the lines clean.

It was a bit of a pain, but now these A-Frames will perform their NFT tasks much more effectively and will require much less effort to maintain. 

As a side note, you will notice in some of the photos that the tubes are marked with letters and numbers.  This is something that was implemented back when this shade house was first built.  It was done to help keep crop and maintenance records.  Even if your garden is small, if you have more than one grow bed, NFT tube system or multiple raft beds I highly recommend that you develop some sort of identification system to make your record keeping much easier.

So how did you spend your week-end?