# Emergent plant filters above tank



## damondeionno (Dec 12, 2007)

I'm in the process of setting up my 90 g corner tank for tanganyikans. I'm going to light the tank very dimly. I am also building some shelves above the tank to house 2 emergent plant filters (partly as a feature, partly to grow some herbs, and partly to reduce nitrate in the tank, which won't have any plants at all.

The 2 shelves will be 18" and 36" above the tank respectively. I am planning on placing a perspex trough on each. The dimensions of the troughs will be approximately 38" x 9" and will be about 6" deep - though I may make the sides higher to prevent an overflow. I am then going to mount lights above each trough - and use relective materials to maximise intensity on the surface of the troughs. The water will be pumped from the tank to the top trough. It will flow through the media and then out through a pipe into the bottom trough. It will then flow through this trough and out through a pipe back into the tank. I will also be using a conventional canister filter in the tank.

Main questions:

What substrate should I use in the troughs? - I need something through which the water will flow freely. An overflow would be bad. At the same time I want the surface to be fairly dense so that evaporation is kept to a minimum.

What plants would people recommend growing (keep in mind that they can't be too tall, must soak up plenty of nitrate)? I would also be interested in anything that will cascade down from the troughs.

The head height will be at least 3.5'. What kind of powerhead would people recommend? Obviously I will want the inlet to be near the surface of the main tank so that in the event of blockage in one of the down pipes or either of the beds, the pump won't empty the tank.

Likewise with the drainage, I wouldn't want a pump failure to result in too much water draining into the main tank. I was thinking about setting the drains in each trough to be a couple of inches from the bottom. In the event of a pump failure a couple of inches of water would remain in each trough and the main tank would not flood. I have calculated the rough capacity of the troughs - conservatively and without factoring the displacement by media.

I am planning to incoporate a light sponge where the water first enters the top trough in order to prevent organic matter entering the bed. This could then be cleaned every so often.

Am I making any classic mistakes? My girlfriend thinks I have completely lost the plot.


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## tkromer (Aug 17, 2007)

The best substrate for this is probably a standard aquarium gravel or even river rocks. You can't use sand or fine substrate because it will get washed around and end up down in your tank typically. 
For plants anything leafy would be good, as well as some floating plants (like duckweed) to fill the rest of the surface of your planters. Once the surface is completely covered with floating plants, evaporation will slow down drastically.
Can't really recommend a specific powerhead, but obviously make sure it's rated for the appropriate head, you're going to want a fairly slow flow rate through the planters but not enough that the water can get stagnant or form pockets.
I've seen a couple setups similar to yours using only one shelf, but not too familiar with the two tier idea, although I don't see why it wouldn't work.
Hopefully some others can add to what I've said..

--Tommy


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## damondeionno (Dec 12, 2007)

My project has hit a small problem. I've built the shelves, but when I asked for a quote from my local perspex fabricator it came to a total of Â£300 for 2 troughs.

I could get a decent sized tank for that!

Now I'm thinking of building them myself out of of glass. Anybody got any tips, advice, suggestions etc?

Thanks


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## Rivermud (Nov 22, 2004)

Why not just use Window Sill Planters.. water in from the top on one side and out from somewhere on the other.. serves the exact same purpose and costs about 5 bucks


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## damondeionno (Dec 12, 2007)

Rivermud

I would definitely be happy with that kind of solution, however the lady who is in charge of the house will likely severely reduce my privileges if my madcap schemes don't meet certain aesthetic standards.


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## iceblue (Apr 27, 2004)

I built my planter directly into my hood for my 350g. I'll be running some tubing from each of my return line to feed it. They will also act as my siphon break when the pumps are turned off.

I used Sweetwater 2 part epoxy to water proof the trough and the rest of it is painted with a non toxic roofing paint.


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## damondeionno (Dec 12, 2007)

That will be a very cool setup. I'd love to see some pictures when the thank is running.


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## damondeionno (Dec 12, 2007)

Ok, some progress. Have all my plumbing bits and pieces and the tanks are being made and drilled. Shelves are up so I feel it is coming together. Anyone got any recommendations on flourescent fittings? I'm thinking 2 feet twins.


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## peterl (Nov 27, 2006)

damondeionno said:


> That will be a very cool setup. I'd love to see some pictures when the thank is running.


ditto! :thumb:


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## mpmitche (Apr 28, 2005)

damondeionno said:


> What plants would people recommend growing (keep in mind that they can't be too tall, must soak up plenty of nitrate)? I would also be interested in anything that will cascade down from the troughs.


Most plants like slightly acidic water, not the very alkaline water of african lakes. Is this for a CA tank or a African tank?


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## damondeionno (Dec 12, 2007)

It's for a Tanganyika setup. My tap water is very hard. I hadn't actually thought about the ph preferences of emergent plants, but obviously they do have them.


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## Rivermud (Nov 22, 2004)

There is an article on this website that speaks specifically about plants for african tanks. Check out the articles.


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## damondeionno (Dec 12, 2007)

Thanks for the tip Rivermud. I am actually building the filters to use non aquatic plants. That way I will need less water in the tanks and can take advantage of a pretty much infinite supply of CO2. This idea is more inspired by aquaponics and hydroponic setups than a densely planted aquarium (I have done heavy planted tanks before). Plants I was thinking of trying were water mint (have grown that on the edge of ponds before and it seems happy with London water). Perhaps some basil (to eat) and I am tempted to try coriander and parsley as well. If I can grow herbs for the kitchen, all the better. The main problem I foresee is getting enough light but I'm hoping that by incorporating reflective materials and suspending the lights just above the plants, I can get good growth.


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## Rivermud (Nov 22, 2004)

I don't forsee any issues with ph affecting the growth of the emergents. I just wanted to point to the article because it mentioned some emergents that worked. And sometimes we go overboard in worry around here.


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## ercnan (Aug 13, 2006)

Not sure on the various types of herbs, but I do know common house plants (philodenderon, etc.) grow very well.
I used to have a length of simple PVC guttering with caps on the ends and holes drilled in the bottom for drains along the back length of my 125. Filled with normal aquarium gravel and fed from a power head. Lighting was from the aquarium excess, and the things took over. I even eventually put some with the roots directly in the tank.
It got to a point that the tank tops were covered and made an interesting "dappled"/ "subdued" look to the water.
A cheap, small house plant became a huge bundle of 6 foot long tendrils going everywhere across the top and down the back.


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## damondeionno (Dec 12, 2007)

That is certainly my ultimate goal.


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## damondeionno (Dec 12, 2007)

WOOHOO, it's finally happening. I have water flowing through both tanks and back into the main aquarium. The spraybar I made is working also. Lights are mounted, now I just need to work on reflective material and baffles, and of course finish the shelving so that my living room doesn't look like a Hammer Horror mad scientist's laboratory.

This DIY thing is great fun!!!!

Because I built it in situ, I must admit to being very nervous when I first switched on the pump. So far, so good, and only about 20 design changes along the way.

I am going to order a 1000 or so bio balls to fill the bottom of the troughs to a couple of inches and then cover them with a layer of netting. On top of that will go white marble chips, and then I can put some plants in and bring the whole thing to life.

Pics of what it looks like so far, this evening.

Mwuhahahaha....


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## iceblue (Apr 27, 2004)

:thumb: Looking forward to the pics.


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## damondeionno (Dec 12, 2007)




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## Stickzula (Sep 14, 2007)

VERY Nice!


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## Mcdaphnia (Dec 16, 2003)

Instead of bioballs and marble chips, there are some great hydroponics "substrates" more in line with the project. Look for Dyna-Rok. It should be perfect for growing plants on top of a filter medium.


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## montano024 (Jan 11, 2008)

Ever though of HPS lighting for your plants? they would explode with growth if you used a HPS (high pressure sodium) light. But then again, HPS lighting isn't the cheapest, my 1k HPS setup cost me $300 w/o a bulb ($100 for the bulb). I can grow almost any plant to maturity in about 9 weeks under my HPS (thats with my hydro setup but i wont go into more detail cause this is a fish forum as i have been reminded so many times)

Just a something for you to think about.


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## damondeionno (Dec 12, 2007)

Thought I'd update you all on this project.

I did opt for the bio balls and marble chips in the end. The big leaved plants are a philodendron species that I had as a house plant. I broke it up into chunks and each section has successfully rooted in the various filter/tank compartments. I'm also growing one from the main tank with its roots hanging in the water. In time I hope these roots will help obscure some of the equipemt that is currently visible at the back of the tank. From what I've observed so far the roots grow very quickly when submerged. I hope to surround the whole alcove with the vine-like philodrendon, mainly for aesthetic reasons.

The plant you can see growing in the top compartment is garden mint (mint sauce - yum). I got a very small plant and again broke it into portions with a small amount of roots attached to each. I simply pushed the base of the plants and roots through the layer of chips. Growth has been extraordinary. There were a few unwanted guests on the plants in the form of aphids. I was a bit concerned at first because I wasn't sure how I could kill them without using any form of chemicals at all (obviously these would enter the water system). To my surprise I noticed that numbers were decreasing of their own accord, and a couple of days ago I noticed a tiny parasitic wasp searching out aphids. Clearly some of their natural predators have sniffed them out. Today I say a small jumping spider in the tank. I seem to have built my own little ecosystem and all are very welcome - even the Mrs thinks it's great.

The second tray is currently empty except for a lone philodendron. I've got a whole lot of watercress and basil seedlings just growing out and I will transfer them in a few days.

As you can see, I still haven't 'finished' the shelves. I need to attach some baffles to the front of the shelves to reflect light inwards. These will come down below the lights. I'm working on some sort of hinged system that will allow good access. Hopefully they will approximately match the white box shelves I built in the alcove on the other side of the fireplace.

Technical stuff:

I was a bit worried about plant roots surviving fully immersed, but it seems that the very high oxygenation of the water (caused by the design of the inflow and drains) means that they have no problems at all. There is a reasonable flow through the system and I think this has contributed to its success.

The marble chips have raised PH to about 8.5, and as this is a Tanganyikan setup, this is great news for me and my fish.

Thanks for the advice regarding hydroponics substrate and lighting. Basically this is a fish focused system and I realise that it is not as efficient in terms of growing plants as it could be. High powered lighting is not really the way I want to go for several reasons. First the setup is in my living room and excess light is not desirable. Second I have slight environmental issues with high wattage lighting for what amounts to a hobby (that's personal btw. I am not judging other people with a different outlook).

Results:

I included the last image of the rocks to show what is has started happening over the last few days. Basically the algae (most of it undesireable) which had grown on the rocks under the low-light conditions in the main tank has started to die and fall off the rocks. Nitrates have been at zero (as far as my kits can show) for some time now. It's worth remembering that my tap water has nitrates between 10 and 20 as a result of reuse of water and agricultural run-off.

Of course it's early days, but I'm extremely impressed with the effectiveness of this small system. I already have plans for future larger setups where I will use conservatory (to make use of natural light) based units to keep a much bigger tank clean. I need to build the conservatory first however. I have kept koi before, and I am planning to build a pond in the garden. Again, I'm thinking about using an adaption of the system to grow vegetables and filter the pond.

One side-effect of a system like this is that people are probably more fascinated by it (and the nitrogen cycle - believe it or not) than they are by the fish themselves. I've got a whole list of people who are really keen to eat some of the produce. Not sure my little system is going to feed many, but I suppose it's the thought that counts.

Downsides:

The system is quite noisy. To be honest, I don't mind it. It's running water and it doesn't get in the way of conversation, music or television. I do live in a city, so there is always background noise anyway. Running water is probably preferable to the other sounds. Perhaps it would be possible to build a silent system, but it is probably beyond my knowhow, and I think that the oxygenation of the water (important for plants and fish) would suffer.

The return pipe into the tank does produce a lot of micro-bubbles - they are really tiny. You can see some of them in the picture of the rocks. Does anyone have a view as to whether I should try and eliminate them? I have set up the return pipe so that it contributes to overall water circulation in the main tank (a bit like a tiny powerhead). I could use some foam or something in the end of the pipe to reduce the bubbles while maintaining flow rate. Any thoughts.

There's quite a lot here so I won't post any more details, only a couple of images when I have finished the shelving. I hope that this thread will encourage people to feel confident about designing their own aquaponic systems.


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## damondeionno (Dec 12, 2007)

One more question. How often do people think I should do water changes?


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## TheeMon (May 11, 2004)

to be honost i dont know(and wondering this for myself)

the plants take out nitrAte and thats the reason why u do water changes...


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## damondeionno (Dec 12, 2007)

Well clearly tapwater contains some nutrients, iron etc, that won't be found in fish food but are nevertheless important for plant growth, so there is a logic beyond simply removing nitrates to water changes. I just wondered if anyone could name any specific substances that needed to be removed or added.


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## Zoban (Apr 6, 2007)

You'll still need water changes maybe not as grequent but still needed ..

As you mentioned the minerals etc that are in the tap water you add though these can be added via things like RO Rite or similar..

The bigger thing is water evaporation lowers the water level as we know but leaves the minerals etc behind that would add to the TDS making it harder softer I forget which now..

Other chemicals etc that we currently can't or don't test for cal also build up in the water over periods of just "topping up"

If I'm wrong so be it but as I remember in other discussions nitrates were only a part of the water changes..


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## damondeionno (Dec 12, 2007)

> If I'm wrong so be it but as I remember in other discussions nitrates were only a part of the water changes..


I think you are right. As you point out, loss by evaporation would lead to a gradual hardening of the water as the salts would be left behind. So even if you were to adopt a 'just topping up' policy, you would need to add RO water to maintain a steady PH at the very least.


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## beanblog (Jun 19, 2008)

Great thread!

Any updates on this? I'm getting ready to build a small system similar to yours in a window.


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