Lettuce Raft 6th Day Update

Phenomenal growth so far!

Replanting of Raft Beds After 4 Weeks of Autopilot

It's been a heck of a time since I posted any updates. That's because I was away on vacation for 3 weeks, and then even after I got back, it's taken a while to get back in the "swing" of things.

The time off served as a good test for the system. Sure, my caretaker watched after it, feeding the fish and taking water measurements. And he threw plants out that were stricken with disease. Maybe it was more of a good test for me! Normally, I can't wait to get back to the farm every weekend to check on things. This is a good thing, but it's also important to have enough confidence in the system and the person watching after it to be able to let go for a while.

All the tomato plants that were in the floating raft beds had to be thrown out. Apparently, they were afflicted by the same black, filmy, bugs that took out my watermelons a month or so ago. The same thing happened to the eggplants.

The floating rafts were proving tricky for the growth of tomato plants anyway. The roots were so developed they were clogging the flow of water from one bed to the other. That's because the floating beds are only connected via a 1" or so pipe and there is almost nothing I can do about that and keep these particular beds.

I will only grow lettuce and other not-so-large plants in them going forward. Tomato plants will have to go into the gravel beds or whicking beds for now on.

I brought the level of fish feed down to 1/2 the normal amount in the last two weeks, due to all the plants that had been taken out. I am bumping that back up to normal now that I have the floating rafts planted again.

I don't have any plans for the vertical grow towers at this point. I obviously need a stronger pump and I don't feel like making that investment right now!

I replanted the rafts beds with lettuce this weekend.
The first video below was taken the day I returned to the farm. The second video shows the planting of lettuce plants in the raft beds yesterday. It shows how to remove the starters from nursery trays, how to wash them and how to place them in the raft beds. Obviosuly, there are many different ways of doing these things, and different people have different "tricks" they use.  Would be interested to know how other people do these things.



If the first video doesn't play, click here.



If  the second video doesn't play, click here.

Pipe Change-Out, 5,000 or so additional (legal) workers, Vertical Tower Build (and semi-fail!)

I decided to change the pipes out, again.  Yes, this is the second time.  I used 1/2" PVC in my first build.  Then I upgraded to a 1" o.d. irrigation pipe (3/4" i.d.) to increase the flow.  That was a huge improvement, but it was nothing compared to the latest upgrade to a 1-1/2" i.d. pipe.  That's a big pipe, and the flow rate is awesome!  The pump manufacturer for the pump (it's a Danner mag-drive "12") recommends 1-1/2" as a minimum to achieve the flow rates they publish, which is why I decided on this size.  I do not know the exact formula, but I am fairly certain that flow rates are proportional to the square of the radius of the pipe, so going from 3/4" to 1-1/2" should result in about 4X the flow, all else being equal (which it probably isn't). 

In any case, the increased flow rate keeps the fish tank water much much cleaner.  That also means there are a whole lot more particles making it to my gravel grow beds, where they can be mineralized, rather than staying floating around my tank, where I am not so sure what happens to them biologically and chemically speaking. 

Here's a vid describing the change-out where you can also see the puurdy new pipes and fittings, and appreciate the super-duper water flow(!):

Also new this week are 5,000 (could be 1,500 or 10,000 or 8,000 - I really couldn't say) new workers and they all fit in the picture below.  This is the latest addition of our amazing friends, eisenia Fetida.  I had added red worms to the system a few weeks (month?) ago, but I also set up some Red Composting Worm bins at home and at the farm with the same batch, so I was a little short with what I added to the beds.  Also, upon reading that they take 60 days to double in population, and being as impatient as I am, I decided to add more the easy way - buying more. 

These were added at night simply by placing them on top of the gravel beds. They moved in and under the gravel fairly quickly.  From what I have read about these worms, aquaponics gravel grow beds should provide near-ideal conditions for these organisms. 

The purpose of adding these to AP systems is so they assist in breaking down organic solids left in the beds.  This mostly consists of undissolved fish waste particles but there are also plant roots, dead leaves and ocassionally fruit that falls off and does not get picked up.  The gut of these worms contains several times more bacteria per volume than their surrounding environment (I read somewhere 13X more) and those bacteria are able to digest a myriad of organic components, some of which we may not even know of or yet understand.  Their metabolization of these compounds releases simpler compounds or elements back into the system - many of which can then be used by the plants.  Red Worm compost and Red Worm compost tea are valuable fertilizers and there is actually a market for them where farmers pay good money for them.  These worms will be producing the same compost and tea right in the grow beds, 24X7 in what is probably very close to an ideal environment for them.  I recently also read that Will Allen at Growing Power, uses red worms in huge quanitities in their systems. 

Finally, as mentioned in the video above, I began to set up two vertical grow towers above one of the gravel grow beds.  These take great advantage of vertical space and my goal is to grow strawberries with these systems.  That in fact was one of the main reasons for changing the pipes out.  I got the towers built, and if you want to see how they are put together, see the video below.  Unfortunately, I still cannot get water up to the top of the towers!  That was a slight dissapointment, and I'll have to figure out a solution.  The towers are nice though, and I can't wait to get them working!

Clarifier Set Up, and End of Times Plant Update

As promised, below is a short video which hopefully explains the new clarifier set up.

To summarize, the original clarifier was a swirl filter.  It was made out of a 55 gallon barrel mostly buried in the ground.  It worked fairly well in terms of trapping heavy particles (i.e., negatively buoyant particles) but I had no way of easily cleaning it.  The only way to clean it was by temporarily pumping the water out and then scooping the sludge off the bottom.  This was very time consuming, and inefficient.

In order to be able to clean it properly, the barrel should be cone-bottomed with a drain line attached.  I have not been able to find any cone-bottomed barrels of a suitable size.  There are some for sale that I could attach a drain line to, but they are much too large for my system, and I don't even think they'd easily fit in the space I have available.

This is the smallest available cone-bottomed barrel I could find.  It holds 303 gallons and measures 1.16 meters across - much too large!!

I don't even want to think of the sized hole that would have to be dug to incorporate this thing.

Because of all this, and looking for something smaller, I decided to try and use a reconfigured 5 gallon jug, like the kind that go on those water fountains:

Placed upside down and cutting the bottom off, these have a built-in cone and an easy way to plumb a drain line in.  I took one of these jugs, cut it in half, and drew the profile out on a piece of rubber (in this case an old dog house):

I then took a second jug, cut the bottom off, and inserted the divider down the middle.  It was glued in place using Duretan.  I clamped a hose onto the neck and attached a PVC drain line onto that, and then buried the jug from the cone-down into the ground.

The result can be seen in the video below:

This thing works OK so far.  Maybe I will like it better with time.  I am not 100% convinced right now but it is definitely better than the prior set up with the unclean-able barrel.

As for the plants, they're doing well, especially since the world didn't end on Saturday.  Here's an update:

Gone Fishin'

I decided to take some fish out of the system this weekend.  The reasons for this are because a) the fish are ready to eat (that should suffice!) b) I have plenty of smaller fish in the system which actually grow faster and process more food by weight than the big fish, and c) I am actually worried about creating an overpopulation problem which could lead to system-wide collapse/death eventually.  Granted, that would still be a few months off.

I'm only talking about three of the largest fish, mind you!  There will be plenty left afterwards. 

I lowered the water in the fish tank by moving as much as possible into the gravel beds, the raft beds, and into the sump.  I set up a small but functional purge tank in an old fridge.  Fish go in the purge tank for a few days (recommended is no less than 4) with no food.  This results in tastier meat. 

The videos below show the various steps involved, and three nice sized Tilapia in the purge tank at the end!  This was a little more difficult than anticipated!  I will have to get better nets for this in the future.

As for my swirl filter, I will update that next week.  I put together a sort of clarifier using a 5-gallon water bottle.  I cannot say yet if it works or not.  It appears to be too short because there is just not enough head created by the jug to force the solids out like they should be.  It does collect solids and I am able to take them out, but it is far from optimal.  If I could only find the exact same thing but 5x bigger!