My first system: Raft converted to Chop Charcoal Media Bed

[Paul Letby]

Hey Gang!  Thought I'd share my setup with you.  It's not pretty but it works.  I chose to enter aquaponics to keep my water change bill down as I was 'fish sitting' this winter.  My neighbor needed somewhere to keep his fish after he closed his pond so I agreed, seeing as I had a 30 gal tank with almost no residents.  I never saw more than 10 goldfish at a time so I figured I was good. Not so.  His water was so full of algae that I never saw all 60 at once!  That put me into emergency mode and I dragged my 55 gallon rainwater barrel into the basement and set up a filter with powerhead. 

After the two tanks cycled I realized that I'd have to do water changes very often to keep nitrates down.  Then I thought about aquaponics!  I'd seen the idea before, but never really considered it because an outdoor setup around these parts would only run for maybe 4 or 5 months out of the year before freeze up.  I did have a light stand in the basement with the barrel though.  So I chose the raft system simply because I had rafts on hand from messing around with hydroponics last year.  I grew lots of lettuce, but didn't like flushing old nutrient down the drain.  Now I don't have to worry!  I built the GB out of lumber with construction poly as a liner, ran some plumbing from the barrel to the GB, found an off season pond pump at the local home improvement box store (75% off!) and rigged it up to pump back into the FT.  Drilled lots of holes in foam to fit pudding containers I drilled more holes in and filled them with gravel, plopped them into the holes in the foam and plunked seedlings into them!  Confused yet?  I am.  Plugged in pump and watched!

Oh yeah, almost forgot.  To keep nitrates down in the 30 gal fish tank, I used some previous experience with aquatic plants to handle that.  4 weeks ago all my aquatic plants in there were just sprigs, except for the sword plant, but it's grown alot too.  I mixed up my own fert (micronutrients, P, K) so that the limiting nutrient would be nitrogen, and so far so good.  Only have hard scale algae at present, and that's very slow growing.  I'm not sure if I need the CO2 injection with so many fish.

Nitrate is almost unreadable for a few weeks now in both tanks.  It was quite scary high before the plants got going. 

Anyway, here's some pics for it all to make sense!

Here's an overview of basement system:

Lettuce view:

30 gal tank upstairs at feeding time!

[George T]

It's just this sort of thing that makes me want to go with an indexing valve.  There are other reasons too.  Congratulations on getting it working.  Plenty of people swear by siphons but I think I'll skip that experience.

Paul Letby said:

Success!  I finally figured out a good configuration for my bell siphon!  It was more fiddling around than I thought it would be.

[Chi Ma]

What if you used a ball valve to control the flow? 

Paul Letby said:

Success!  I finally figured out a good configuration for my bell siphon!  It was more fiddling around than I thought it would be.  I think that my be because I chose a pipe size a little too big for my waterflow from my pump.(3/4" pipe, 1" to 3/4" adapter at top of standpipe, schedule 40 fittings with 90 gal/hr measured)  On Affnan's design for his mini siphon he specifies a single elbow below the standpipe.  I found if I added any more than that my siphon would not cut off.  However if I only used one slip fit elbow the siphon wouldn't start.  Conundrum!  It seemed that the water just flew out the smooth slip fit elbow without much turbulence and never piled up enough to start the siphon.  I cut a very short piece of pipe to stuff into the elbow to narrow the flow and that started the siphon, but it took ages to stop.  I've run it like this until tonight when I just got fed up and started fiddling again.

I ended up picking up an elbow that was slip fit one end, threaded on the other.  I figured the threaded end would produce a slowing turbulent effect to the water, allowing it to back up enough to start the siphon, and yet be large enough that at the end of the cycle the siphon could gulp some air to break.  Sure enough it worked!  Forceful starts and sharp cutoffs within 5-10 seconds of sucking air.  Happy dance!

 

Here's a pic of the difference between the two ends.  It is hard to see the threads in the elbow on the left but they're there:

[Paul Letby]

I've seen it done, but generally was not looked upon favorably by the other members of that forum.  I think if you can get it figured out with your hardware, you shouldn't ever have to change it again.  You may end up tweaking your valve if biofilm builds up inside it.  You may have to run a pipe cleaner up this thing too every once in a while, I haven't had one before.

[Paul Letby]

The charcoal GB is finally done!  Well, sort of.   It looks like I'll have to dig up my bell siphon strainer.  Up until now the media has been floating a little bit with every cycle.  This let all the little pieces migrate toward the strainer, and now it's all bunged up.  The siphon is breaking before all the water has a chance to make it through the strainer.  All I have to do is dig it all up then replace the strainer and surround it with good size pieces of charcoal.  Since the media doesn't float anymore there shouldn't be much if any migration of the smaller pieces towards the strainer.  That shouldn't take me long, but I'm tired now and want to post this then go to bed.

 

I took my African Violets out of their pots, washed the roots as best I could and put back into their pots with charcoal.  I kept them in pots so I could re arrange them as I wish, and turn them so they grow symmetrically.  It was pretty cool to finally put something alive in the charcoal.  I also scattered the live babies of my Kalanchoe, aka Mexican hat plant.  It reproduces by both live clones that fall off it's leaves and by seed if it can live long enough to flower (2 years).  I have one growing in the rafts, but it got massacred by the aphids.  They really scarred it up, and destroyed the growing tip.  A note on how hardy these plants are; I had stopped watering the parent plants in late spring.  So it's been about 8 months from last watering, the parent plants have finally withered but the live young are still taking root.  That's tough!  I also planted a basil seedling, and a beet seedling.  The beet may not be happy with the sparse light.  I need to drop the fixture down a bit.

 

Anyway, enough yammering here's the pics.

 

African Violets never come properly potted from my experience.  The medium is usually too water retentive and causes the plants to be prone to rot.  I've copied this layering method from someone off the internet and had great results.  My hand mixed soiless mixture on top and a third gravel on the bottom.  I always water from the bottom.  It's all coming off, oh the carnage!

 

After heavy leaf removal:

 

Here's his buddy after similar treatment.  I'm testing the planting depth here at max water level.

The carnage!  Oh the humanity!

 

And here's the results!  I still have a few African Violets left, but I'm not sure I'll keep them.  They're kinda the runts.  I've grown all these from leaf cuttings from my Mom's plants.  The miniature on the left is a sport.  Not sure what the little one will do, it hasn't flowered yet.

 

[Paul Letby]

Oh yeah, one more thing.  Please don't reply by quoting my posts.  That really makes a mess.  No one wants to see all these pics repeated again.   Please use the 'Reply to this' on the bottom, not the one from a particular entry.  Thank you for entertaining my anal moment.  :)

[TCLynx]

or if one must reply with the quotes, ya can go in and delete all but the important bit so we don't have to scroll past everything multiple times.

[Chi Ma]

Crybaby 

[Harold Sukhbir]

Success to the "Charcoal Guru". The black background of the bed gives good presentation and really highlights the plants, looks like slate or granite to me! The harder you work at AP the greater joy in reward. If this is sustainable over time, this method will probably be adopted by many, the main reason being the weight of the media.

[George T]

You might want to try a simple filter made of landscape cloth wrapped around your standpipe.

It looks like I'll have to dig up my bell siphon strainer.  Up until now the media has been floating a little bit with every cycle.  This let all the little pieces migrate toward the strainer, and now it's all bunged up.

[Paul Letby]

 

I was just reading on Murray Hallam's practical aquaponics forum and found two members who've been using wood charcoal for a while now.  One of them had a system running for two or four years, I can't remember.  I think his name was Daveoponic or some such.  He covered it with a layer of gravel for planting into.  He recently dug it up and reports that it didn't lose it's structure, no breaking down.  So it looks like we've got another source for info on charcoal in GBs long term.

[Paul Letby]

Now that's an even better idea!

TCLynx said:

or if one must reply with the quotes, ya can go in and delete all but the important bit so we don't have to scroll past everything multiple times.

[Harold Sukhbir]

Combination with gravel, interesting, so can we say about half the weight?