Nitrate Filter - Another Project?

  • #1
Ok, so I can't stop! Here it is, and thanks to susitna-flower for the idea. A nitrate filter, with a difference.

My partner loves plants and I love fish. Can I combine the two with good effect? I think so.

The idea is this: make a raised, tiered garden above the fish tank and pump the tank water slowly through it to remove the nitrates, nitrites and other chemicals such as heavy metal traces.

The theory behind this is sound. plants need nitrates and other chemicals to grow, and CO2 as well. Submerged plants are limited by the supply of CO2 in the water, air plants are not. A selection of water-loving plants would grow very well with the roots submerged in water from the nitrate-enriched fishtank, and the tank water would be greatly improved by the removal of the nitrates.

The practical application:
Building this garden above the light canopy of the tank would be simple, so long as the plants chosen don't grow too high. The suggested plants () are lucky bamboo, which could be trimmed as needed to keep the height under control, but water lilies and other pond flora would fair just as well and be less likely to grow too high. basically, any water plant would have the desired effect.

How to do it:
This has still to be designed properly, but a basic concept has already formed and the sketch below gives you the gist. I guess I've found another use for polycarbonate! A water pump that moves 20 gallons an hour would be sufficient for this application, and should move enough water to get nitrate removal working.

Here's the questions:
Can it work under practical application?
Are my theories sound?
What plants would be ideal in this situation?

Input please folks!
  • #2
I have grown vines and mint right in my filters. The tubs we put outside last summer had this type of filter

My only problem was if I didn't vacuum the gravel in the filter occasionally it began to smell like poop, but as you can tell the parrots feather loved it, and the water parameters were good.
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  • #3
One potential problem could be low light levels. Being high up, it would get very little natural light, and limited light from the water columns either side. Would this limit the plants very much?
  • #4
Would lighting like these be of help to bring enough light to the plants? Particularly the full-spectrum or the nutri-glow or the 50/50?
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  • #5
Sure would! Started thinking of alternatives as soon as I asked the question, and have already got to grips with this problem.

It's gonna be neat! lol.
  • #6
Oh SNAP!!! Same thing I was looking at doing just not with a garden.. You must do this!! I have to see it work.. ;D

You are my hero!!
  • #7
Sure would! Started thinking of alternatives as soon as I asked the question, and have already got to grips with this problem.

It's gonna be neat! lol.

and the engineering begins! I look forward to the results, it's a very innovative idea and the way you delve into these building projects is how I feel about coding software or producing a DVD.
  • #8
FLBettaCouple does software ?? If you do web stuff PM me if you woudl like to help me with a project... Sorry for the thread jack.. I am done.. ;D
  • #9
How about an outside pond using the same theory. I reckon that would be a great way to combine the two.
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  • #10
Any ideas as to the type of plants to put in this little garden? I have decided to make it as ornamental as possible with curved tiers, rather than straight ones. This will also allow larger plants to be used.

Here is the start of the build. I am using my favorite material again, as it can be shaped easily. The plan is for three tiers, the top two are here in skeletal form:
  • #11
I do love your projects timg! i'm becoming more convinced you just don't sleep!! You get through your projects so fast!! i'm looking forward to watching this one develop!!! good luck!! tan
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  • #12
Been working still, now we are almost finished on the build. Ended up with not three but five levels and the option to use it to filter two tanks, depending on how effective it is. Either way, it's gonna make a fantastic addition to our tanks and will be the center of attraction above the 8' tank.

I just need to do a little more to the build and fit the drainage and pumping to it before I can test for leaks. We will be looking for plants tomorrow to put into it. my partner wants a water lily and several other water plants, so it should be fun finding them!

Here are the next batch of pictures showing all the different levels, the water cascade slots and the overall look of the shell. We have decided not to decorate and cover the plastic, because it is going to be sat on top of a light box, the light will shine through the plastic and really enhance the whole thing!
  • #13
i'm with tan - WOW! that sure is coming along fast!
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  • #14
Another day and more done. The support frame has been mounted on the wall, the unit was leak tested and plumbed in.

We have decided to go with the plan of supporting 2 tanks with this aquaponics garden, working on the principal that even if it doesn't work 100%, it has to be better than nothing! It is plumbed into the 4' tank with the water column, a total capacity of 62 gallons imperial. The tank is heavily laden with fish, at present containing 5 goldfish, one coi, 6 young angels, 2 young silver sharks, 2 young rainbow sharks, 8 danios and two ancistrus. Water changing on this tank has been twice-weekly at 25% per change, due to the load of fish in there. Filter cleaning has also been twice weekly for the same reason. It seems like the perfect tank to run this test on!

The aquaponics garden has been divided into two sections, this tank will run on the smaller section of the two. It has a water capacity of approximately four gallons imperial, after substrate has been added. The pump will circulate at around 20-30 gallons per hour, taking water from the far end of the tank and putting it back into the near-end. Hopefully this will force the circulation and ensure that the water chemical levels remain balanced.

Tomorrow I will locate a pump for the system and hopefully get it running. We have pre-filled the garden with water and should be able to put the plants in tomorrow as well. I did a 25% water change on the tank today, so tomorrows reading should be accurate. To be honest, this will be a first for me too, as I am not accustomed to testing on a regular basis, just tend to rely on my judgement, which has never let me down before. I will admit that the water changing of this particular tank is a pain though, and if it can be avoided, I will be a very happy man!

I plan to do a nitrite/nitrate test on the tank before I start the garden working, to give me a baseline for the test, and hopefully will not need to change the water ever again! (Well, that's the hope!)

I will document the test results which I will be taking weekly. I don't think it is going to make a vast difference straight away and daily testing would IMO be a waste of time.

This project will take time to prove itself, so keep watching the thread.
  • #15
wow ! can't wait to see it with the plants when they're all settled in and see your results! good luck. i'm sure it will be success! should get that patented and mass produced along with your upside tanks!
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  • #16
I'd get bored with making many of them. But I really think I should be having words with the manufacturers of the polycarbonate, 'cos I'm sure they never imagined the uses that could be made of it!

just to let you know, I went for a walk with the dog and came back with a bag full of pond plants! They don't come cheaper than that!
  • #17
just to let you know, I went for a walk with the dog and came back with a bag full of pond plants! They don't come cheaper than that!

Excellent!! ;D
  • #18
In the lower trays you could grow a vine that would hang down your wall and make a sort of "living wall". You could use something like a Golden Pothos vine which will grow anywhere and in anything (some sites say it won't grow with "wet feet" but I've seen it grow in a bowl of water with large gravel in it and it was a 10' long vine). I don't know how well water lilies will look as they are better enjoyed if you can look down on them like in a pond and your tanks there seem high on the wall. No matter what you end up with, it will be a cool addition to the room.

By the way, I was doing a google search for something completely different and stumbled on . It talks about it for a saltwater tank, but there isn't any reason it couldn't be made to work on a freshwater system. It's not pretty but it would get the job done. Just saw it and it reminded me of this thread, so thought I would share.
  • #19
dude, don't take this wrong, I mean it in a good way, but are you some kind of bio-engineer with too much time on your :
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  • #20
Nice system, but I think mine will look much better! lol.

I don't know how well water lilies will look as they are better enjoyed if you can look down on them like in a pond and your tanks there seem high on the wall.

The thought has occurred to us, but we won't know until we try. As for the height that the unit is installed at, the reason for this is the missing 8' tank, which will eventually sit underneath! (When it finally appears!) It looks a bit daft now, but that's the reason for mounting it all the way up there! The plan for the end result will be 8' running under this unit and another water column to the left of the unit, evening things up. Please be aware that until three days ago, this was never even thought of! I think it's called utilising all available space!

Whether it works or not, it is a neat trade-off between plants and ornaments, which was the original plan for this area!

dude, don't take this wrong, I mean it in a good way, but are you some kind of bio-engineer with too much time on your

nope, just fanatical about fish, and want a pleasing and relaxing environment to live in, while the fish have the best that I can create for them!

I love some of the new tanks and equipment out there, and it's fine for those with lots of money to throw at their hobby, but I haven't got unlimited resources and am rapidly running out of space for tanks, so have to improve on what I already have and make sure that it will serve it's purpose long term. We also have to consider the fact that I now have some 200 gallons of water in my living room, with another 150 gallons of tanks still to install, and a water meter in the road outside! IF this functions the way it should, then I will dramatically reduce the amount of water that goes down the drain, as well as reducing the cost of maintaining the tanks. Don't forget, this filter is designed to clean two tanks, a total of over 200 gallons of water. Without it, I would need to perform weekly water changes on both these tanks, running some 50 gallons away each week. With it, I will only have to top the tanks up periodically, and prune the plants when they grow too big! (Can you see the logic?)
  • #21
i'm just amazed at how you can figure out how to build all these creations. I think if I built all that, i'd have 350 gallons of water.. on the floor and heading out the door. It's really quite skillful and I do think you could run a business building custom aquarium setups for businesses and the rich (they'd have the money to make it a profitable endeavour).
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  • #22
It's really quite skillful and I do think you could run a business building custom aquarium setups for businesses and the rich

If someone was to ask me to create something for them, I would be very happy to oblige, (at the right price!), but I don't have the time or resources to get a fully fledged business running. Maybe one of the Custom aquarium companies out there would like to enlist my services on a "when needed" basis, I don't know.

The other side of this is that what I am creating has not been tried before, and I can't put any guarantees on it. If it fails, I get wet and a little embarrassed at the failure, but no harm done. If I were to install something like this in someone elses home and it failed, what then? Is it worth the risk? When I KNOW that things work, that's the time to push them out to others, until then, I would prefer to keep it close to where I can control it. When you design a software program, you might get a few people to betta test, but you don't release it to the general public until all the bugs have been eliminated, do you? (Microsoft made that mistake a few years ago with ME and that cost them dearly.)

But, saying all that, if you know of someone who would like a unique setup created in their home or business, and would be prepared to take a chance on the outcome, let them know about my designs and I'll be happy to talk to them!

Even over the pond wouldn't be that much of a problem, with travel as easy as it is these days! (I could do with a nice paid holiday!)
  • #23
Very good points, I see where you're coming from. And should I come across someone with the money to pay for it who wants a custom setup, I'll be sure to refer you to them. I'm in a small town, but many members are in cities with a greater chance of customers with deep pockets. Who knows what could happen for you with these great creations?
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  • #24
Ok, the system works, at least water-wise!

I found the pump I was looking for in an old washing machine, and with a little re-hashing of the intake, managed to make it work the way I want. It cost me a few pounds on fittings, but much cheaper than buying a new lift-pump. A picture below shows it working.

The control valve came straight off the shelf at the local DIY store and enables me to utilise the pump in more than one way. Not only does it supply a trickle to the aquaponics garden, but it also supplies a very powerful jet of water to the base of the water column forcing circulation in there too! I love making things work!

The figures:

The nitrite/nitrate test results today:
Nitrite 0
Nitrate 30

I expected a high reading on the nitrates, as that is why I have to do water changes so often. I will test again next week, but will almost certainly need to do another change before then, as the garden won't take the strain imediately. For the next couple of weeks, the results are going to be hard to guage because of the need to keep the nitrates under control while the garden establishes. I don't want to put the fish under un-necessary stress by letting the levels climb too high.

the plants we have got now are free ones that I found while out walking, so they don't look particularly special, but given time we will replace with ones that we want. The flip side is that as these are wild plants, they should respond very well to the enriched nitrate water being supplied to them, and not worry too much about lower light levels. They should also be very fast growing, which may cause a problem down the road a ways! It will be something of interest to see how things like the moss respond to this setup too. There is not a lot of places for it to root on the verticle sides and I'm interested as to whether it can!

I will fit the lighting tomorrow which will undoubtedly improve things. For the mean time, here is the way it's looking right now:

put the lighting in place today, and did another nitrate test, expecting to need to change the water, but the reading was onlt 25! Can't be the effect already, surely! it may be a result of the 4 gallons of water that I put in the garden before starting it up, I suppose.

Anyway, not done very much today, been busy fitting UGFs in the other tanks!
  • #25
Looking Great! I wish we could come over and take a tour of your aquarium creations.. maybe sometime in the future you could post a vid on youtube or google video with the link here? I think a LOT of fishlore members would watch the video with envy. (we would)
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  • #26
Spent a lot of time today tidying the job up and fitting the canopy front for the lighting on the tank, when it gets here. Did another nitrate check today, only to find that it has dropped by another couple of points! I guess this has to be having an effect already, unless something else is taking the nitrates away!

I took all the real plants out of the tank last night, since the fish insist on pulling them up, so they are no longer having any effect either. Something is definitely happening here, I just find it hard to believe it can happen this quickly. But hey, there are new shoots on the plants and the have all greened back up beautifully, so why not?

Does anyone know what effect slow filtering has on ammonia? It has occurred to me that the bacteria that breaks down ammonia will also be growing in the aquaponics garden, and I just wondered whether this will have an effect on the water cleanliness as well. maybe I will be able to reduce the amount of main filters in the tank as well? We'll see.

I suppose this isn't a lot different from a sump, except for the volume of water running through it. I must admit that I am wondering what would happen to the plants if they clean all the nitrates out. maybe I should look towards plumbing in a couple more tanks so that I can alternate the source. Strange how the mind works!

Forgive my wanderings, it happens sometimes. The project does seem to be working already though, much faster than I expected. maybe this has to do with the fact that I used mature plants rather than young ones, maybe it's because they are wild ones, or maybe I'm just willing it to succeed!

Anyway, back to the project. below are today's photos, this time taken in daylight, which shows the plants and their surroundings much better. It also shows the new canopy front, which matches everything else of course.

maybe sometime in the future you could post a vid on youtube or google video with the link here?

As requested, here's the link(s):

and the main living room
  • #27
That just looks so freakin' awesome! Thanks for the vid! Great to see it in motion! ;D
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  • #28
I think I have found out where the nitrates are going! take a look at the picture below, the two shots have been taken just 2 days apart:

There is over 3" of new growth on at least 2 of the plants, and new shoots and leaves appearing everywhere!
Sparkling Diamonds
  • #29
TI'm I have to say, you are an inspiration! Your living room is lovely, i'd love to actually be there to see it and appreciate it. You really are quite passionate, and to encorporate the plants in like that is fantastic. I'm envious of your many tanks...i'll admit it.
  • #30
Unreal...I have got to say you have really taken things to a new level now. Very impressive.
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  • #31
Finally I've had the news I have been waiting for! the new tank will be ready for collection on Saturday afternoon, along with the new 2' and the glass to make the other water column. All I have to do is travel to wrexham, some 100 miles away with a van to collect it, then it's back home, out with the paint, paint the back and then work out a way to get this monster into the room!

It will probably have to come in through the window, which I shall have to de-glaze for the purpose, but getting it on to the shelf will be a challenge, since the canopy is almost complete and I have only left 3" to play with length wise.

Then the aquaponics garden will really prove itself, as I have abandoned the idea of a sump and expensive canister filters in favour of..... UGF and aquaponics! The two should work out fine, if the early results from the tests are anything to go by!

This tank is the final piece of the complete setup, and if you've watched the videos, you know where it's gonna fit by now, so once it's in and working, I guess I will have to stop creating new projects and let someone else take over here!

However, back to the project in hand. Today I filled the other side of the garden with sand and water, ready to start adding plants over the next few days. The aI'm is that it will be fully functional before the new tank is ready to run, offering instant filtering and bacterial support and avoiding the huge cycle that tanks of this size normally need. The Fluval is already loaded and waiting, and the immense impact that the aquaponics garden has had on the 62 gallon tank has really thrilled me.

The readings are down again today, this time to less than 20ppm, a drop of 11 points in just 3 days, and no water changes! The plants are growing like mad and the tank is so clear that I can see straight through from one end to the other without any distortion. I have never had it this clear before! The garden isn't just taking out the nitrate, it is also cleaning the water of other impurities as well by the look of it.

Interestingly, the nitrite reading has remained at 0 as has the ammonia, which is despite the shut-down of the fluval 4, the main tank filter, so there is nothing detremental being added from the garden and it must be taking up the slack from the powerhead's shutdown. Answers an earlier question as well, doesn't it?

Now the question arises:

Who decided that for good filtering you have to turn 10 times the volume per hour? The garden is running at 15 gallons per hour (that's only 25% of the volume per hour), and appears to be doing more than the fluval ever did! I suppose there is a possibility that the ammonia is escaping to the air with such a slow flow rate, or else the plants are breaking it down for their own use, I don't know, but all that is filtering the tank now is just two air box filters that struggle to keep a 2' tank in check!

I have a feeling that we may see a few more of these creations appearing on here soon! I hope so, it would make me very happy to see others getting the thrill this is giving me. It's strange that no-one has bothered with this type of thing before. I guess technology rules out there and manufacturers have blinded us to the real truth a bit and blinkered us to think that their products are the only way to go!

Most light canopies are larger enough to take an aquaponics setup and with a little reinforcing, could do a splendid job of it too, as well as helping to clean the water, it also releases oxygen into the air and removes Co2. What a wonderful thought...... Every fish tank out there with it's own little garden, better air quality, less co2, and no more water changes.... Could it happen? lol

Here's todays picture, showing the continued growth of the garden and hi-lighting more new shoots in the background. I really think that we are seeing seriously accellerated growth here!
  • #32
All I can say is WOW WOW WOW. What an aswome job you've done in the set up of those tanks. How do you do it?? Natalie
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  • #33

One step at a time, making sure that everything is ok before going onto the next step.
  • #34
Totally sweet!!!

With your inspiration I decided to add a few plant's (inside) my aquarium that are known for being nutrient hogs (horn wort to name one). I measured my Nitrates the day before and got a reading of 40. I did a huge 5 gallon water change (its a 29 gallon tank) and tested it again.. Got 40.. LOL!! I just tested it today again and got a reading of 5!!! ;D So far this is the 4th day in a row of Ammonia - 0 --- Nitrite - 0 ---- Nitrate - 5.... Simply AMAZING!!

So I am guessing with an over the tank set-up like what you have maintaining an over stocked or huge tank would be easy... Must continue the testing!! This is great!!
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  • #35
So it's not just me.... it really does work!

Thanks for that gargoyle, I was starting to think that my readings were wrong! I was also thinking that it was going too fast, but your readings are supporting mine for timespan as well. It's really great that someone is testing my theories and not just leaving it to me! Cheers!

For the next project...... a two-way syphon device to enable water changing from the claen aquaponics tanks to the not-so-clean non-aquaponics tanks. Any ideas? as most of the tanks are on the same level, it's not going to be as easy as it sounds. I will need to find or make a pump that can draw both ways at the same time at the same rate. that way, I can pull nitrate-rich water from the one tank and replace it with nitrate free water from the other tank in one operation.

The advantages: continued growth on the garden without nitrate depletion, clean water into the other tanks without any polution, lower water bills, less hassle, simple one-stroke operation.

When: As soon as I have time!

Isn't it fun when one thing leads to another!
  • #36
Possibly 2 power heads with hoses attached and flow control valves. You could monitor the levels and adjust the valves accordingly until you have achieved the water "switch" you are looking for..

From some of your other posts it sounded like you had some power heads that are not being used at the moment.. ;D

P.S. Glad I could help and I will be monitoring the levels over the next few days as well..
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  • #37
That sounds like a plan! Only the one head would have to be moved around with the outlet from the other head, which could stay in the clean tank all the time. I like it! Thank you gargoyle!

Another day of growth and another huge drop in the nitrates! the reading was down to 12 today, and I brought the second section online too, so next couple of days should see it drop even faster!

here are todays pictures, and what did we say about lillies? You decide!
  • #38

I should check my Nitrates today... If I do I'll post the results back up here.. ;D

Well they were at 5... Today they are at 10... I will re-check in 4 more days to see if they stabilize.. If not then I will have to look into one of your creations!! ;D
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  • #39
I wonder if this has to do with co2 availability.... In the tank it is limited and a restricting factor for the plants, out of the tank it has no bearing. This was the main reason for creating the garden, as co2 will limit growth irrespective of nitrate levels in the water, whereas the garden can get as much as it needs with no restriction. This could very well be the difference between our two experiments.

have a go at building a garden on top of your light canopy and see if that works better!
  • #40
What plants are good for such a thing ?? I live in Michigan so most of the "water" plants we have around here are HUGE!! I would guess so that they don't die over the winter..

I will draw up some plans and play with some ideas... I am thinking that moving my HOB filter up a few inches to supply the garden with water should work out perfectly.. ;D Now to figure out how to make it work with my limited space...

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