Wednesday, April 20, 2011

Lettuce Raft Production in 25 Days; New Vertical Stacking Component

The plants are looking fantastic, and are growing at a good clip too.  The lettuce seen below went in on March 25th - that's 25 days ago.  Not all of them are ready to harvest, but 9 of 15 are.  The others I think will take another 2-5 days, depending on which particular head we're talking about. 

At UVI, in their fully-optimized system developed over a span of 30 years, they get full lettuce heads in about 21 days, so this isn't a bad second-trial.  That's more a testament to how easy aquaponics is than to anything special about my system. 

Below are two vertical grow towers I just installed on top of one of my gravel grow beds .  They're designed for strawberries and are made by a company called VertiGrow out of Florida:

The pots stack one above the other and are filled with support media.  I will pump my fish water up into the highest one. The water will percolate down to the next pot through holes at the bottom of the first, and eventually through the other pots and into the gravel grow bed.  I am hoping to use these for strawberries, although it is hard to find starters here.  If not, I'll have to come up with something else to grow in them, which really shouldn't be hard.  They are a great use of vertical space.  They provide 4 planting spots per container - one per corner, so each one of these towers can hold 20 plants.  That's more than each of my floating rafts. 

My fish have multiplied and grown quite a bit since I started.  That was 6 months ago with 5 adult fish.  I have no idea how many fish I have now.  There are easilly more than 60 and quite likely over 100 at different stages of growth.  This is actually a horrible way to keep fish, as I learned at UVI.  The correct way entails separating the females from the males, keeping separate brood stock, and managing stocks of fish at similar growth points.  I won't get into details here, because doing so is really an entire aquaculture course in itself.  Suffice to say that is is very important to grow out a portion of your total capacity in controlled, timed, amounts, and to maintain your line's genetic purity by keeping separate brood stock.  I may change my system drastically down the road and actually produce fish the correct way.  For now, I'll just continue with what I've got, knowing it is not the most efficient way to do so.  It does suffice for a home-based system of this small size.  The fish are doing great at their main job, which is to produce plant food.

One of the problems with all the fish growth is that my swirl filter appears to be having "issues":

That's floating fish gunk, fortunately not making it down the exit funnel and into the rest of the system.  I am not sure why it is floating.  It shouldn't be.  It should be settling at the bottom of the swirl filter where it can be scooped out later.  In any case, it isn't, and it's time I change this filter system out for something easier to clean, so I'll be focusing on that in the near future. 

And here's a quick video update of all this.  If it doesn't appear below, click on this link:


  1. Such an awesome blog, I'm learning a LOT! Thank you!