Backyard Aquaponics
A place to discuss aquaponics

Hi guys,

I have been reading heaps of stuff on the net and in this forum trying to get as much info before jumping into what looks to be an awesome journey.

I am hoping to set up a small NFT system due to space limitations using a 500L FT.

I am planning on using 4 * 2m (90mm) rows of PVC which should be able to hold 40 plants.

I am wondering about what type of pump I am going to need?

I have read that NFT systems require a bio-filter before going into the piping. Would a canister pump work as a bio-filter or would I need something else?

I have also read about sponge filters. Could I use a sponge filter between the FT and the cannister pump intake?

Also with a set up this size what size pump do I need. Would 2000L/h be enough?

These are only some of the questions I have. I am slowly planning bit by bit and can't wait to start this project.

Thanks guys.

Baz

If I was going to toy with NFT again, in a small system, I'd:
1) Use a small aquarium/fountain pump to lift the water from the FT to the highest point
2) Discharge into a solids filter. A bucket full of shade cloth will suffice (this will require periodic cleaning, so make it accessible). Overflow returns to FT. Discharge the filtered water into the biofilter.
3) A second bucket of shadecloth would suffice as biofilter (you wont have to disturb this one nearly as often) or bird-netting or plastic bottle caps, or floss, but even better would be to spend a few $$$ and get a proper biofilter media such as kaldnes k1 or kaldnes mini (a couple of litres would be more than ample) and use a slightly higher flow rated pump to agitate the media ala MBBR (moving bed biofilm reactor). The biofilter discharges excess flow back into the FT for aeration.
4) If the NFT pipes are "online" they discharge back to the FT.

When you flood the NFT tubes: 8m of 90mm pipe holds about 50L or about 10% of the FT volume from full so you shouldn't require a sump but I'd be considering CF as opposed to a timed F&D. Don't try and force too much flow through the pipes as overflow will occur. Ensure to anchor the NFT tubes to prevent them "capsizing."

This is a design I was going to help a friend install, until his Minister of Home Affairs put the kibosh on the whole fishy idea.

Is the NFT going to be staggered vertically or is it going to be all on the same plane and are you going to use rectangular real NFT troughs or round pipes?

What fish do you intend to keep and how many?

You also get a big smiley probably only from me, for the canister filter suggestion.

Bunson - Thank you for the very informed reply. It has given me an insight into biofilters. I am planning on doing CF and am trying to build it as simply as possible. Will take your advice on board.

Sleepe - I am thinking about using round PVC and staggering them vertically. 4 rows, 2m in length.
As for the fish, I thought silver perch could be best for the Melbourne climate. Cold in winter and roasting in summer. I did however have some rainbow trout for dinner tonight and would love to stock these through winter at some stage.

I am curious why would the canister filter option not be a popular one? I was thinking if I could pump and filter all in the one device it would make things a lot easier.

I understand it will work out a fair bit more expensive than the method Buson suggested however.

I found this pump and it looked like it could do the job:

http://www.theaquariumshop.com.au/shopexd.asp?id=3975&name=Aqua+Pro+Canister+Filter+2200

Any thoughts.

Cheers.

Canister filter will do fine, you simply wont see many people using aquarium products here, its usually cheaper to make your own and most people use growbeds rathr than just NFT.
depending on food rate, you may need to clean your sponges occasionally, the solids wont break down in your canister like would happen in a growbed, etc.

If you buy that exact canister, you will want to remove the activated carbon noodles, maybe replace with bioballs or more noodles.

Yavimaya - Thanks for your input. Is is simply a cost issue with the canister or do they not work as well as other pumps?

I am beginning to think a cheap pump and building a bio-filter, like the one buson mentioned, could be the way to go. I little bit more plumbing will be required though.

The thing with canister filters is that the sponges capture the solids, which then need removing because they wont break down so well in the canister. There is a high likelyhood that if you get a canister with built in pump it wont be as good $ for flow rate as a normal pump, because you are paying for the cainster too.

The other problem with canisters are they are pressure filters, so your pump has to work against that pressure, therefore you lose flow rate no matter what happens.

They are also sealed, so if your pump turns off for half a day or more then your bacteria will die and your cycling will need to start again, a normal growbed / open filter can be turned off and the bacteria will survive for ages - days rather than hours.

I have done a DIY biofilter, but system only been running for a bit so can't say how successful it is. From a water clarity point of view works a treat.

This is just something I thought up today, but what about a couple of your NFT pipes having some Foam in them, like a sideways Zip Grow? I am about to move my system, and am trying to think of some inventive ways to keep as much bacteria alive as possible, as I don't know how much of my bacteria on gravel will survive a move, moving gravel ain't exactly a quick process!

This is not exactly right. Solids will break down in a canister filter but in order for the system to be sustainable you either have to make the canister MASSIVE or the load on the filter tiny. Alternatively you need to clean them out regularly.

A canister filter would fine if used after a RFF.

Aquariums don't need much filtration because aquarium fish are fed to survive. AP systems need lots of filtration because AP fish are generally fed to grow so they produce lots of waste.

So even with the canister filter I will need some extra filtration possibly before it?

Looks like either way, if I start up a NFT system that won't have a growbed, (no space for one), with a canister pump or a cheaper style pump I will have to add some for of pre-filtration to the system . Is that correct?

If so, what type of cheaper style pump would work on a system this size?

I think I am going to do some more research into building a DIY bio-filter and also a RFF.

Any other further leads are greatly appreciated. I am learning a lot from all this input.

Thanks.

An RFF followed by a canister filter will give you a solution but you will have to remember to empty the solids that collect in the RFF and clean the canister filter or equivilent on a regular basis.

Just found this DIY filter:

http://www.earthangroup.com.au/diy-solids-filter/

If I made this using a 30L bucket do you think it will do the trick?

Any other DIY plans any knows of out there?

Paul at earthangroup has somewhere a series of calculators to be able to size your filter correctly. Whilst your there have a look at some of his ideas for his systems, which, are basically AQ systems which can run without GBs, combined with AP with the installation of GBs, e.g. http://www.earthangroup.com.au/evolution-of-aquaponic-designs/ for such an idea, which also includes solids handling via a bio digester. It's a good source for ideas.

What other things do you need DIY plans for?

Sorry I took so long to get back to this.

A couple of comments

I had not realised you were going to try and grow edible fish, 500l is not a big FT.
If you have a little extra space I would keep the NFT on one plane and run a manifold to them rather than daisy chaining them together, it saves on head etc.
If you are going with Bunsons idea remember this is a stylised diagram and the RFF and moving bed biofilter do not have to be above the FT just high enough to provide the head to drive your troughs, see the same plane comment.

The reason I like cannister filters for ornamentals is
No pump in FT, if you can get them secondhand (even with a stuffed pump, should be bugger all) you can daisy chain them together, putting matting in the first and biofiltration in the second and only clean the first.
This means your solids are not trashed by the pump and cleaning should be a breeze.
You have effectively given yourself a useful sump without all the drawbacks. You can even use an inline pump your cannisters are only there as mechanical and biological filtration.
You save yourself from HSM by putting a small hole in the intake pipe about 2-3" under the FT waterline.

Hope this helps

Buson - Great advice. I checked out the calculators on that site and it looks like a 25L bio-filter should do the job. Having a look now at some of his system ideas. The design you posted earlier is starting to make more sense to me now.

As a newbie I am still trying to grasp all the lingo and ideas.

Sleepe - Once again thanks for your input. Technical stuff there. I had to reread it a few times to digest it all. I thought about starting out small with a 500L FT due to space and also because I found one cheap on eBay. 15 odd fish should have enough space in there, shouldn't they?

Looking like NFT is not the easiest way to start out as a newbie. Is it really as complicated as it all sounds. Will it lead me to a HSM?

As a beginner, would it be easier using an IBC and building a grow-bed system?