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!

[Paul Letby]

I'll throw a few pics here to show what I did tonight. Harvested some lettuce yesterday and didn't get around to cleaning up the pots til today, so on the right is the light stand before I beefed it up. The roots on that lettuce are crazy!

Here's a shot of after basic work done:

And then a few bits to keep it all in place:

I'm thinking of placing the GB on top of this section of skid. The 2X4's span the gap nicely and the slats hold them all upright and spaced well. All the weight is transferred onto the two rails as the shelf was never meant to support this kind of weight. I climbed in there and laid down on the skid, so it'll hold me with nary a creak. Glad no one got a picture of that!

And back to normal for the violets and seedlings for now:

[Sylvia Bernstein]

Hey Paul. This all looks great! With those plants you are probably ok with 6 - 8" of media. Just assume that you'll need to clean it out at some point.


Paul Letby said:

I've been anxious to get my next flood and drain GB installed with the charcoal media. Today I finally had some time (read stole time from something else) to get started. Tonight I beefed up my light stand to handle the added weight. Lots of squeezing into tight places, fiddling and farting around. That part is done now, and next will be building the GB itself. I have yet to settle on a depth for my GB because I'm not sure what to do about height to the lights. This one probably won't lend itself to being adjustable, so I'll have to settle on a fixed space between the lights and the bed. The deeper I make the bed, the less room I have between the media and the lights. I plan on only growing lettuce and herbs with this bed, so there doesn't have to be very much room between the lights and the media. Basil can be trimmed to control height, so I think I'll base it on height of lettuce. What should I be shooting for?

[TCLynx]

Seeing as it is a basement system supporting the goldfish out of the neighbor's pond for the winter? Perhaps if you make sure to add a pound of worms to the media bed come spring (if there are not already lots of worms in there) then leave the system fishless for the summer but with the water cycling around to let the worms work on the solids and old roots, perhaps cleaning might not become needed? Maybe?

[Paul Letby]

Thanks Sylvia. That's probably what I'll have to do.

Sounds like a great idea TCLynx. Worth a shot anyway, as I'll likely have fish again in the fall from him. I have a worm bin in the basement and will transfer over a bunch once the GB has been running for long enough to accumulate some fish gack. Thanks!

[Paul Letby]

Came up with another question as I'm about to purchase pipe for my autosiphon. My current setup pumps 90 gallons/hour measured at the output height. I put the output hose into a one gallon bucket at the same height as the water level in my barrel, then timed the fill. 40 seconds. It's rated for 150 GPH but I think that's with almost no lift. It's pumping through a 1/2 inch hose. I was looking at 1 inch pipe and fittings for the bell siphon, but is that too big for the amount of water I'm moving? I can always bypass some water to the GB, but I can't make the pump flow more water. Affnan in his videos says his bell siphon is good over 15 watts, and mine is 10 watts, but I don't think he mentions GPH. Any thoughts?

I had originally looked at a loop siphon but from all the reading I'm doing I'm not so sure anymore.

[Sylvia Bernstein]

Paul, I sent a note to Affnan to ask if he could jump in here and lend you a hand. Hopefully he will give you his thoughts.


Paul Letby said:

Came up with another question as I'm about to purchase pipe for my autosiphon. My current setup pumps 90 gallons/hour measured at the output height. I put the output hose into a one gallon bucket at the same height as the water level in my barrel, then timed the fill. 40 seconds. It's rated for 150 GPH but I think that's with almost no lift. It's pumping through a 1/2 inch hose. I was looking at 1 inch pipe and fittings for the bell siphon, but is that too big for the amount of water I'm moving? I can always bypass some water to the GB, but I can't make the pump flow more water. Affnan in his videos says his bell siphon is good over 15 watts, and mine is 10 watts, but I don't think he mentions GPH. Any thoughts?

I had originally looked at a loop siphon but from all the reading I'm doing I'm not so sure anymore.

[TCLynx]

There is also a chance that if you upsize the plumbing from your pump to the grow bed that you might see a little more flow from it.

Unfortunately I don't know the math right off to tell you what size siphon will work for your current flow rate.

[Affnan]

Hi Paul

150GPH is a bit too small for a 1" stand pipe, it will work on 3/4" (20mm) like on my mini kit. I would suggest 250 ~ 350 GPH for a 1" stand pipe. More than this you need to divert excess water, having said that under optimum condition it should work up to 450GPH without diversion.

Hope this help

Affnan


Paul Letby said:

Came up with another question as I'm about to purchase pipe for my autosiphon. My current setup pumps 90 gallons/hour measured at the output height. I put the output hose into a one gallon bucket at the same height as the water level in my barrel, then timed the fill. 40 seconds. It's rated for 150 GPH but I think that's with almost no lift. It's pumping through a 1/2 inch hose. I was looking at 1 inch pipe and fittings for the bell siphon, but is that too big for the amount of water I'm moving? I can always bypass some water to the GB, but I can't make the pump flow more water. Affnan in his videos says his bell siphon is good over 15 watts, and mine is 10 watts, but I don't think he mentions GPH. Any thoughts?

I had originally looked at a loop siphon but from all the reading I'm doing I'm not so sure anymore.

[Paul Letby]

Ok, time to get this growbed done. The rest of my month really seems to be getting squeezed for time, so today's the day. I have some design challenges, such as not enough room to pass plumbing underneath the bed and a light fixture below the bed, so no drilling through, so I'm going to drain it out the side to a small container where the bell siphon will reside. I'm making the connection between the bed and container twice the size of the stand pipe, so hopefully enough water will move into the smaller container to keep the siphon fed. I anticipate a longer time for the siphon to cut out as the last bit of water migrates into the container. Here I go.

[Paul Letby]

Well, that idea to drain the GB to the side and siphon from there has been ditched. Too complicated for a little set up like mine. So I ended up drilling through my light stand just in front of the light fixture. I spent 4 hours running around town to find all the parts I needed, so that was 3 hours I didn't spend in the basement working. Not done yet.

I built the wooden GB, put the liner in and installed the stand pipe with LOTS of silicone sealant. Here's hoping it doesn't leak in the morning when I fire up the pump. I removed the overflow to the raft bed underneath and set it up to drain into the media GB. Right now the bell is a pop bottle so I can watch the action. Tested it out in a bucket set at the same height as the GB. It worked great when I set it up the way Affnan recommends, but not so good when I extended the plumbing and added a second elbow. The way it's set up now I'm concerned it may splash a bit. If it does I can extend the plumbing lower into the raft bed.

So now I have a modified CHOP setup, where the sump is my raft bed. That shouldn't be a problem as the two GB's are roughly the same volume, and the media in the upper GB will displace a good chunk of the water. My rafts float free so they should have no problem moving up and down. I think the increased aeration will be good for the plants. Testing tomorrow with no media will be the max weight it'll ever see as my media is charcoal and very light. I'll put buckets of water into the bed first to displace a good chunk of water so I don't suck air with the pump.

Anyway, here's a few pics.

[Paul Letby]

Another little update. Siphon issues solved, it's now properly set up. I had to play a little with my bell as I'm re-using an old plastic water bottle. My first design with the serrated bottom didn't work as the plastic is too thin and flexed, nearly sealing the bottle to the bottom of the bed. I simply cut those off and cut two slots similar to the intake on a Murray Hallam bell. Much stronger, works good. It's simply cool to watch a bell siphon running.

Charcoal bits are plugging up the pump, so I installed a fish net at the end of the siphon to catch them. Works good. I pulled all the rafts and swirled the fish net pulling a few cups of fine charcoal up, then swirled after that with the pump running to lift all the dust through the system to be trapped back in the flood and drain bed. I also have a sponge filter running in the FT for now just to help clarify the water.

[Sylvia Bernstein]

Thanks for your continuous updates, Paul. I know personally that, while I'm not commenting, I'm reading them all with interest. Keep it up!