# suggested media choices for aquaponic trough over tank ?



## Fishfur (Mar 4, 2012)

Just wondering if anybody has any ideas for suitable lightweight media to place in a large trough that will be sitting on the top rear of my aquarium. Tank water will be pumped in at one end, flow through, and then drain back in at the other end.

I'm wondering if it should it be all the same type of media, ore more than one type, perhaps layered in some way ? It will be full of plants which are intended to take up the nitrates and the bacterial content should break down most of the waste eventually into usable food for the plants. 

I wonder if there should be a sponge at the "OUT" end, which would catch any particles that might get through the trough's media, so it would not drain back into the tank. This sponge could be cleaned periodically. The whole system is intended to function as a very large biofilter, taking the place of the existing HOB filtration. I may leave a sponge filter inside the tank, but haven't decided yet if that will be the case. There will be a circulation pump, to prevent any dead spots and also to provide current for the filter feeders and fish that enjoy a current. Most of my fish are species that like moving water.

The troughs are going to be mounted on top of a pair of 30" long tanks. One 29G, one 25G. I hope to replace the 25G with another 29G if I can find a suitable used one at a good price, but it will make no difference other than appearance and the slightly higher volume of water.

The first media I thought of was Hydroton, the expanded clay pebbles you often see in those wet vases with plants in them. It is very light weight, but unfortunately it does float and it's not cheap, particularly not in the amount I'd need.

I'm going to look at hydroponic places to see what they offer as well. I don't want rock wool, I think it would be much too messy if or when the trough had to be cleaned out - and it's so dense it might just clog badly too. I'd thought of pea gravel, but I suspect it would be much too heavy, and awkward to work with when adding, dividing or moving plants.

The troughs will be made of acrylic. They'll have some horizontal bracing pieces on the underside that I hope will provide added bottom support to the trough, but which I also hope will make a good spawning area for mystery snails, as they'd sit in the water to be accessible to the snails. Troughs will be situated on the top of the tanks, overhanging the back edge by an inch or two, and extending an inch or two past the tank ends as well.

There will be as many plants growing in the troughs as they can support. They'll include house plants but also some marginal pond types, that like wet feet but not necessarily to be submersed. They're in a south window, so the plants in the troughs should do well enough in terms of light. Lighting the remainder of the tanks and their plants might be awkward, haven't completely worked that part out yet.

Plant roots will have all soil removed, then be planted to grow in whatever media I end up with. The dirty tank water coming in will rise and fall in level, but the troughs should never go completely dry, as water will be pumped in continuously. The outlet will be a type of siphon I've seen plans for that should prevent any chance of overflow. But one reason I think a sponge at the 'out' end would be useful is that it could be easily cleaned if it got too clogged. There will be a very coarse sponge intake cover over the intake pipe in the tank, to catch the coarsest of particles and bits of plant and prevent fish and shrimp from being pumped into the trough. I hope the troughs themselves won't ever need to be completely cleaned out, but it will be possible if the need arises.

Any suggestions appreciated.


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## pyrrolin (Jan 11, 2012)

one concern about a sponge at the end is if it got clogged and you didn't notice right away, would be a huge mess


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## Fishfur (Mar 4, 2012)

Good point about the sponge.. though you can have similar problems simply by not cleaning the Aqua Clear often enough . 

I've looked at some aquaponic sites now, most seem to recommend using at least 50% LECA.. light expanded clay aggregate. Hydroton is one brand. 

Others call for a mix of LECA and coarse perlite, or scoria, which is a porous light weight rock like pumice or lava rock, and formed in the same way as lava rock. 

If I could find it in a small enough particle size, lava rock might work. Scoria does not seem to be available locally, though one garden centre lists both black and red lava rock. I emailed to ask the general size of the particles. If they are too large they'd be awfully hard to work with. I'm guessing I'd only find coarse perlite at a hydroponic place - but I really don't care for perlite much, and it's very dusty when dry, and not good to breathe at all. Vermiculite works too, but tends to compress over time, which causes its own problems.

Might just be stuck with LECA, maybe I can find a bulk supply that's less costly than the little bags most garden centres have.


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## zfarsh (Apr 7, 2011)

I personally use hydroton, it was like 30$ I think for a big bag, and I use it throughout the house, thus giving more justifications. Yes, some of it floats, whilst some of it doesnt. I use it as biomedia in some of my filters too (HOBs), as bed media for my aquaponic system for my Mints, as media inside transparent holders (Riparium style) for emergent plants in my large aquarium, etc.. I could also use it as just plain like "soil" in a normal pot and have a plant in it. Anyways, all I am saying is I like having it in the house for various purposes.


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## matti2uude (Jan 10, 2009)

I use Eheim efilav filter media as substrate in my Sulawesi shrimp tank. It's the smallest form of lava rock I could find. It would work for you but is costly.


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## Fishfur (Mar 4, 2012)

I appreciate the suggestions. I'm thinking hydroton is probably what I"ll end up using. Btw, zfarsh, where did you get the big bag for 30 bucks, if you remember ?

Matt, I will look at the Eheim media too, but I suspect it will be too expensive for the amount I need.


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## zfarsh (Apr 7, 2011)

Second Nature Hydroponics, they are in Missisauga on Royal Winsor. I bough many piping stuff / connections and a nice pump from them too, it was really good price for the pump and a good one too. They even drilled my bin for me and put the connections on it (which I bought) for free.

http://www.secondnaturehydroponics.com/contact

I called them, and they have it stock for 28$ and its about 50lbs or something. It's 8 - 16 mm sizes, they don't have anything smaller (or bigger right now), and that is the size I have too. It is not branded as Hydroton, but it is the same thing. Don't forget to clean it up a bit.

Once, they even gave us a lot of fresh grown on their system veggies, all very good of course. I very highly recommend this shop.

You could use the hydroton as media for plants in your house or veggies / plants in pots if you want, that's what I started doing, and as bio media for the filter too for new / used filters you may purchase. It is very light, so that can be a plus, and yes, much of it floats, so have it on mid to top, and have sponges bellow it, and grow plants in your aquarium. I have a lot of mint growing, and they are tall, and you can make them grow like week if you keep trimming them and putting the cut parts back in water so they grow roots and multiply. I started with tiny small 2 - 3 piece, and now i have a big chunk in my 75g aquarium, in my long 2 - 3 ft aquaponic (filed with hydroton) system, and will bring soon bring to my work as a plant companion too once i find a good pot.

good luck


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## Fishfur (Mar 4, 2012)

Thanks Zfarsh, that's very kind of you. Doesn't matter if it's Hydroton, it's all LECA, no matter what brand it might be. Based on the prices I've seen for this stuff elsewhere, I sure don't think I'm going to find a better price than that. Sheridan packages theirs in very small zip bags, for a couple of bucks each. I think by the time I got to 50 pounds that way, it would probably cost me over a hundred dollars ! Won't go to waste here, I grow tons of plants. Size sounds good too, it's not as coarse as some I've seen.

Fresh grown veggies sound pretty yummy. I wish I could do that here, but I very much doubt there is enough light to grow veg. Quite possibly I'll manage a few herbs, but in winter, even mints might struggle with the light. They won't get it from the tank lighting, unfortunately. 

But even if they are not veggies, it will be nice to have plants in this window again. Before I put the tanks here, there was a pair of stepped plant stands on the shelf I built over a bookcase, which held dozens of plants, so that I never bothered to draw the curtains. Even though the tanks are great, I sure have missed the plants being there. So this is going to be a nice way to sort of have my cake and eat it too.


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## zfarsh (Apr 7, 2011)

I remember it was a huge bag, so not 100% sure it is 50lbs or 25lbs, but should be enough for many projects. They have best pricing I think, I have shoped around in the past and liked them best.

Just buy live Mint from a ganden place or Walmart or similar, and cut some of the stem and put the cut ones in water, and let them get roots. This one is the easiest thing to grow of anything I have tried, and is the only thing that grows well in my current systems, as I have tried many other types. In fact, even just putting the mint in a pot of water near the light / sun is enough to get the roots going. And then, keep multiplying them. They will clean the air of your room, and repel many bugs!!! Also, mint, you can keep cutting it, and it will keep growing back. I don't know many (or any) other herbs you can do that with.

Have fun


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## Fishfur (Mar 4, 2012)

Too true. Mint is a tough customer. I actually have some water mint, which I'd never seen before, until I ran across it in a pond plant place. It's just a mint that likes wet feet, and it's very minty, so it would make lovely mint jelly, or garnish or even mint for roasting with lamb. So I'm hoping it will grow nicely once I get the troughs going.


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## zfarsh (Apr 7, 2011)

Hey Fishfur, I just finished all my hydroton building another mini project. If you feel the bag is too big for you, I can always buy 1/8 to 1/2 of it from you once you are done with it, no rush of course. Good luck, and hope you enjoy it.


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