Backyard Aquaponics
A place to discuss aquaponics

Hey "furnaceboy"... you make continual references that suggest some past/ongoing aquaponics experience ... with different systems...

How about starting a thread of your own.. and showing us what you do???.... please...

That is my plan Rupe. All in good time. I am still just a newbie on the forum, so haven't had time yet. Still trying to track down some of my photos and info. I have had lots of exposure and experience over the years to the fish/aquaculture side of things, with aquaponics only new to me in the past 3 or so years. Still learning lots (my passion), and in the process of putting in a new 4 bed system.

That's because I only posted a pic of one I did right! If (when) I screw up another one, I'll take the required pics.

Going one size larger uniseal would make the problem worse. The larger they get, the harder they are to use. If I can't get them to work with the KY and the pipe clamp method (see this section of TCLynx's Tower System thread), I may punt down to 2" uniseals as Dave Donley suggests, or spend the dough for bulkheads.


I'm pretty sure it has been done before, although I can't come up with an example at the moment. Anyone else?

I've never intended to have a huge amount of fish in the system. And I'm deliberately trying to keep the solids in the system. I may have used too small of a gravel to get the flow rates I'll need. We'll see! If so, I'll swap it out for bigger gravel or for scoria. I'm all about the trying of things and sharing the knowledge. That's why we're here, right?

Go on Karen, you are doing a nice job!


Rupe you rule!

Raft methods are not as common among people over here on this forum but the gravel bed doing filtration for raft beds is a growing trend right now. It is a kinda new trend so we don't know yet quite what the minimums are for making all this balance right. Chris Smith in HI is replacing most of his settling tanks and net tanks with gravel media beds for his originally Friendlies style low density raft systems.

For ages people have figured you could add on rafts or NFT pipes after the media beds in a media bed system. Now people may be pushing the limits of the gravel beds solids handling abilities by using relatively small gravel beds to filter for a large amount of raft troughs but it may take a few years for solids clogging issues to arise if they are low density/well aerated systems. And then it will probably just call for the addition of some more gravel beds perhaps with larger media. Or sequential flooding of a bank of gravel beds to keep up with the flows without overloading a single gravel bed.

100 gallons might or might not be enough, depends on Karen's stocking. Looks like there is enough room for 1, 2, 4? IBCs in front of the troughs if necessary to add more. Karen is it one IBC per bed + trough or maybe it looks like one IBC per two beds and troughs?

DD, right now it's 1 IBC per greenhouse bay, and each bay has 4 troughs.

The water goes from the IBC, splits in two, and each stream goes into a gravel bed. Each stream then goes into a trough that runs down and then back through the greenhouse bay, and dump into the sump.

I may not have enough fish tank, or enough gravel bed filters, but I can always add more with this design.

Speaking of which, I got my second trough almost ready to go today:

Putting in the liner:




(my #1 helper, Fer (short for Jennifer))

Putting in a few inches of water to help it fit in correctly:


I got uniseals put in on both ends, as documented over on the Uniseal problem thread.

There's a freeze warning for tonight! It's only mid-September! Waaaaaaahhh!
(It should warm up again in a few days)

By the way, if you'd ever like to zoom in on any of my pics, or see higher quality versions, they're all over on my Howling Moose Picasa album. I intend to put copies of the pics I use here into my BYAP Gallery too, that just takes a bit longer.

Last winter I put together a system for housing 450 tilapia indoors. The fish tank was 300 gallons, the biofilter was one 30 gallon drum filled with biofill. http://www.aquaticeco.com/subcategories/2637/Bio-Fill I got my bio fill from the guy that makes it for $15/CuFt vs the $49/CuFt that others charge for it;could have made it for less by turning pipe on a lathe. So that might be something to consider if the gravel gives you problems.

Big thing is flow rate and aeration. I cycled my tank volume 4 times per hour and I achieved good aeration of 9 ppm using a spray bar to churn up the water very harshly in a second drum. I used a swirl filter made of a 50 gallon drum to settle solids followed by some brushes. This system worked pretty dang well considering how cheap it was. It worked better than my polygeyser filer. It seems to me that an AP system can be very small if designed properly and using a proper bio filter. Then what ever size and type of beds you use will work. Infact the most productive system I have ever grown in was a deep water culture with aerators under each plant so perhaps this raft thing has potential.

Keeping some solids in the system would be good I guess, but I think the composting roots and worms are what makes a mature system pop with growth for plants other than greens.

My gravel gets stopped up once in a while when feeding heavy or having an algae bloom, but then I stock pretty heavy. Even with a 1:1 setup It seems I exceed the amount of nutrients my fish and gravel grow beds can produce depending on what I grow.

Anyway, your system is looking good, and I will look forward to seeing some info on growing using a raft system. How many fish does it take to grow 100 head of lettuce ect... It seems to be 1 fish per square foot for my 8 inch deep gravel beds.

Keep up the good work!

This would make a great how - to book, or a booklet...either way you should make a few videos along the way, and sell advertising to help pay for your costs!

Anyways, I'm very interested in your progress, and to hear about the things you are learning/considering along the way.

Thanks again for taking the time to share,

Jeff C

Come on Karen... pull your finger out... thought you'd be finished by now...

Hang in there. And as to what is enough fish or filtration for the rafts well that balance is still being researched so you will be part of that research. Chris Smith and Phillip Wolf are both doing systems where media beds feed Rafts. I do know that Phillips Tomato jungle did give him some trouble steeling the nutrients so there didn't seem to be enough left for the raft beds but that was in the system's first year of operation. Phillip's set up at We Grow Dreams near Chicago is in a heated greenhouse. Chris Smith In HI is converting his bio-filters (settling tanks and net tanks from a Friendlies style system) over to gravel beds to feed his rafts and he is running a small commercial operation so he might be one to pick his brain for numbers.

The types of plants being grown certainly play a huge role in the nutrient levels as does water chemistry. My 300 gallon system has had heavy plant growth this summer and I can't seem to get enough fish into the little system to keep up. Perhaps growing vines that cover the oak trees is a bit much for a 300 gallon fish tank to support. Then over in my big system I've got a rather light fish load currently but the nitrates in that system with the high pH always seem to run high.

Will be interesting to see how these sorts of hybrid operations go... I reckon they may well out perform the existing "friendlies" model...

The biggest question will be.... Will you have to clean the gravel beds regularly or not???????
And that will depend on many things so it will take a while to answer that question I'm sure.

I do know that many people are starting to set up systems sort of like this so we should have tons of examples to see what happens over the next few years.

TCLynx, do you mean this We grow dreams?