Side/Side Experiment: Hydroponics/Open-Loop Aquaponics

[AJ Grottke]

I am going to be running a side by side test run indoors under grow lights.  On one side i have hydroponic greens and herbs and on the other side same plants but i would like to try a open loop aquaponics system.  Im running ebb and flow for both grows (2, 2'x4' trays for each grow style) with some plants in hydroton filled 3"net pots and some with peat-based soiless mix in 5"pots.  Each 4'x4' area of e&f tray space has a 20gal res.  For the AP side im going to fill up the res with water from my some of my fish tanks.  Then im going to test and measure EC and PH.  From there i will add additional mineral nutrients and organic boosters(only as needed to achieve top quality) to reach my desired EC (i will run it at a lower than hydro, b/c i read that AP water is hard to test nute strength by EC; though im not sure how true this is).  Then i will aerate, mix, and adjust/maintain an intentional PH drift at 5.5-6.5, where hydro plants preform best.  Also i will be able to add as much calcium, iron, or anything else deficient right away, in the required doses for the plants w/o having to worry about the fish being hurt. After 1-2 weeks i will pour the AP/nute solution onto my fruit trees and garden and replace with fresh.

My questions are if anyone is running a open-loop system and has any tips they want to share?  I also was wondering if anyone has made some kind of filter bucket? Something that i could pour the FT water through, before nutrient solution make-up, to reduce clogging that the AP water in my system might cause.

Here are some pics of the hydro side, providing me with lots of food a few steps away from my kitchen. (literally, its the closest room to my kitchen) When i say local i mean local!  IMO when people buy local foods from local farmers, not over 120miles, i consider this regional (though this is what everyone calls local); and local is you grew it in your house, yard, or your neighbors grew it and you traded for it with something you grew.  If your not growing your own, then its highly likely you will be consumed by the eternal consumption engine that the global economy has programmed us to live within.  We need so little, its not even funny; yet we always want more.

[TCLynx]

Open loop aquaponics, isn't really aquaponics, it is just using your fish water to water your plants.

And, adding hydroponic nutrient to up the EC values to what you expect for hydroponics is really going to defeat the purpose of a side by side test isn't it?

An EC meter is testing for electrical conductivity which comes from the salts used for hydroponics.  Aquaponics doesn't use those mineral salts and can have a rather high nutrient content and almost nil EC reading.

[AJ Grottke]

Well, ive seen this debated plenty of times, but i still believe "open loop" is aquaponics.  I dont feel the definition of aquaponics contains the fact that water MUST be recirculated; plus i want to take some water out because my trees and tomatoes outside love the fish water. Regardless of the name, i would like to use the waste from my tilapia in aquaculture tanks to feed plants grown hydroponically; which then feeds my trees and outdoor gardens.  I have already tried ebb and flow systems with no clarifier or mineralization tank, and they went extremely poorly.  Too much gunk in the system and i even had a really low stocking rate.  Im trying to benefit from the waste stream my fish are producing by just adding it to my hydro systems which are already fully functional (and paid for a half decade ago).  If i wanted to build a closed loop AP system id have to spend money and build stuff; neither of which i have resources for now.  I am still putting all my resources toward my mushroom farm.  So with that said, when i fill up my hydro reservoirs i always just go "hey, why cant this be water from my aquaculture tanks?"  Answer:  Too much settle-able and suspended solids.  I like my roots looking clean in hydroponics,  When plant roots are covered in fecal matter they grow poorly.  So i guess i should redirect my question to:

What are simple DIY filtration setups that can be made cheap and dont necessarily have to be plumbed into the system? (eventually when i get some $ i will build a 55 gal clarifier and mineralization tank for a recirculating DWC AP system, but until then any quick/cheap options are appreciated)  I may just take a the water out of the FT and let it sit for a day or two to settle out some larger solids(air stones on or off for this?) Then take a bucket and drill a bunch of small holes in the bottom and fill it with cheap sheets of blue aquarium filter foam from the pet store. Then pour the water through the bucket filter and it into my reservoir; then add nutrients.  Any comments?

[Jonathan Kadish NYC AA Chair]

By your definition all aquaculture is aquaponics, all that fish waste always goes somewhere and grows something. Nobody is saying you can't or shouldn't do what your doing, it sound pretty cool. It is just not aquaponics, and if you keep calling it aquaponics you will confuse people when they see your set up and go to find information on how to do it.

[TCLynx]

Well, I don't know that there are any really super cheap yet still effective methods of removing solids from your effluent water from the fish system to put into your hydroponics system.  See a fish system with a healthy active bio-filter will have bacteria in it which will try to grow bio-slime and will probably still give you some issues with your hydroponics equipment if it has really small pipe or tubing sizes involved.

but, options for effective solids removal.  Cheapest is probably your settle the solids out for a day or so idea.  No air stones for that.  Let the water settle then siphon off only the clear water leaving the solids undistrubed then you can take the solids and gunky water out to your dirt plants.

another possible option would be a slow sand filter but that will have more cost of course.

I fear simply running the water through aquarium filter foam will clog the foam quickly requiring frequent replacement and probably won't catch the really fine stuff very well but otherwise could work.

Now if you were doing a run to waste thing before where you simply pumped fresh water through a fish system and then to the hydro and then out, that wouldn't work well because you need to recirculate at least to an extent in order for the nitrogen cycle to even work.  Hydroponic plants don't really take up ammonia and if you are not recirculating enough to let a bio-filter work the nitrogen cycle, then you are definitely not doing aquaponics.  And definitely, if you don't have enough media to take care of filtration for you, then aquaponics will do poorly.

Aquaponics is about the filtration.  The bacteria and all the micro and macro beasties that do the mineralization down in the grow beds or where ever your filtration is.  The system can function sans plants or fish for a time but Bio-ponics doesn't function without the filtration.  Doing aquaponics is about farming bacteria and all the other little beasties that live in the filter.  That's my opinion and I'm sticking to it!