anoxic filters.

[sam51]

hi all, am serously looking into a anoxic filter.is there any views about it on here.i have emailed the guy who first brought this filter to the fore.but seems a bit like lord lucan,

[Manky Sanke]

Sam,

If you are talking about emailing Kevin Novak, this guy copies me in to many of his emails and they are so long and detailed that they must take him hours to write so he is always snowed under with the backlog and you will have to be patient.

In the meantime, Kevin is in the US and I'm his Brit-Branch so I get to answer most questions that are generated in the UK. And because I was so fed up with people who didn't understand how it works and the beautiful simplicity of the system running it down, that to help him out, I've put his CD book onto my website and I've written a couple of articles about the system.

This is his CD book
http://www.mankysanke.co.uk/html/anoxic_filtration.html

You can go for the full-on science if you think you are up to it but it might be best if you read the introduction first - I wrote that. I also designed a modification to make it suitable for gravity fed systems because the original design was for pump fed but most of us Brits prefer gravity. What goes on inside the baskets is horrifically complicated bio-chemistry. Kevin describes his system in full hard-core scientific detail, but when I write about how the baskets work, I try to use language that is understandable to the average koi-keeper.

So wadda ya wanna know?

[Manky Sanke]

Sam,

I've got your PM, your list of questions and the suggestion that I should answer them here so that everyone else can see is a good idea but you want quite a lot of detail and l'll be busy writing for the next few days so sorry for the delay, (I'm not doing a Lord Lucan), I'll get back to this early next week.

[kayoss]

Sam,

I've got your PM, your list of questions and the suggestion that I should answer them here so that everyone else can see is a good idea

The answers are no good if we don't know what the questions are in the first place!

Don't understand why questions are asked privately via PM with a suggestion to answer them publicly!

Cheers

Bob

[Manky Sanke]

No worries Bob,

The questions are the sort that are frequently asked so I'll put the questions and their answers on here along with some information about filtration in general that is poorly understood. It would take longer to explain what I'm thinking about than I have time at the present but by way of an example, two weeks ago I was asked to answer a question sent into Koi Carp which was asking about how much water a bag of Alphagrog would filter and why didn't the manufacturers or suppliers of media put this information on the bags.

[sam51]

Sam,

I've got your PM, your list of questions and the suggestion that I should answer them here so that everyone else can see is a good idea

The answers are no good if we don't know what the questions are in the first place!

Don't understand why questions are asked privately via PM with a suggestion to answer them publicly!

Cheers

Bob

the questions were posted on another forum,the reason being was that forum was the one doing all the talking about it.
even occasionally kevin novak was posting on there, as i am about to start this filter system,i needed to know everything about it.
i have now sufficient information to believe in this system.
i did find there is plenty of people doing alot of talking about it,but not actually doing it,[buy the way talk is cheap].
as for your comment about private pms,i don't see the point in long winded posts about this system on here,when no one is using this system.so that is why i ask syd,with a email,as he is the only guy that seems to know about it,and use it to the best advantage in the uk.
if syd wants to answer my questions on here,i have no problem with it,
after reading syds version of this system on his site,over and over again, i have now got my head around it,
i also spoke to a guy yesterday, who as far as i know was the only guy in England to have used this system.[for some reason he is not using it at the moment.]but said it was a excellent system and will be going back to it.] you just have to have the balls to do it.

[kayoss]

Hi Sam

That sounds reasonable mate.

Now you have sufficient information to believe in this system, would you care to share the questions you asked and the answers you got on here so that we can all learn from it please?

Maybe you could paste it on our club site too so that our members can also benefit from the extra info you've obtained since Syd came to talk to us?

Cheers

Bob

[Manky Sanke]

Sam,

Since I began helping Kevin to promote this form of filtration, I have received more emails than I could even estimate asking for information. Many of these people go on to build the system as an addition or in a few cases as the sole form of filtration for their ponds. I get lots of positive feedback from satisfied "customers" including some high profile names and I have never had any negative feeback. The amount of time I've spent answering email and PMs about this over the past couple of years is huge, especially when there is a forum post which turns into a long thread which then sparks off some interest in building the most natural filter system that could be imagined and which is not being sold with a load of sales talk and a thousand pound price tag.

My reason for answering questions more publicly where possible is so that those who are interested can see what I have to say without having to send me mail. I don't begrudge the amount of time I spend answering email or passing on information but if I can find ways to reduce it, it means that I occasionally find time to have a life for myself as well.

F'rinstance, I gave a talk at your club two weeks ago, took away some water samples to test but although I have the results of those tests, I still haven't had the time to examine them and write up reports and/or give advice. I shouldn't be writing this now because I'm on a deadline of "crack of dawn" tomorrow then another one asap after that, but I didn't want you to think I couldn't be bothered to reply to you or that no-one was using this system.

So deadlines first, water reports next and I'll get back to you asap after that with all the information you need.

[Manky Sanke]

Bob posted that while I was typing, but that's a good idea. There was quite a bit of interest by a few of your club members and the subject came up at the end of the talk when we were already already over-running the time the room was booked for so I had to be brief. Post any information you already have on there. Every little helps and it may reduce my work-load by reducing the questions I get for your club members. Mrs Manky will appreciate that because it might mean that I get to paint her pergola.

[sam51]

ok guys i am not one for writing long posts on Internet,but in the mean time i will try to help syd and take a lot of the pressure off him,
about this system.
these are my thoughts on this system and why i will be using it,[please correct me anywhere where i'm not quiet right syd]
i like this system,because the filter media and the baskets,are more or less self maintaining,
they take the nitrifing process one step further,ie instead of a end result of nitrate,we end up with no nitrate,or what ever reading is coming out of your tap.mines about 20ppm,my pond at the moment is probably 80ppm.but this will depend on your water changes.
kevin novak reckons 2 water changes a year,will do.but this is something i disagree with.it also depends on how you set this system up.
as the yanks seem to do things different from us.if i can get down to 20ppm,and hold it there,i will be happy.
next. how to set it up.well this is not a small foot print system,like a bead filter. you need some aquatic plant baskets,11"x11"x8",
filled with cat litter,this is the tricky part.you need to buy 100% clay based natural product.it must be the non clumping type.with no
perfume or odour control in it.i have found at the moment,pets at home, there own brand will do,after experimenting with it
i had it in a basket,in a container full of water,when stirred up the water went gray in colour.i done this a few times,and changed the water.the basket is now sitting in water and is crystal clear.what will happen when a flow of water goes along i don't know yet.
by the way the water will flow around,under,and over the baskets,not through it.
i have also been looking at a clay,called moler clay,this comes from denmark,this is a 100% natural clay,used to plant bonsai trees.
apparently this is what is in tescos lightweight cat litter. i will let you all know when i decide what to use.
you also need the final ingredient a product called laterite,you can get this off ebay,either api,or fluval do it.
for the science be hind all this,please look on syds website,ref anoxic filters.
now my planned filter set up.it will be an oblong box made to my spec.it will be 2m x.7m x .8m LXWXH.
i am limited for space. a 4"pipe will come from bottom drain into the box,with a 4"90 degree bend with a 4"pipe in a vertical position.
this will have a series of 1"holes drilled in to it.to act as a diffuser,for a even flow,and no tracking.i will then have a row of 3 horizontal brushes 6 in each row.so a total of 18 brushes,these will be on separate frames,so i can lift out a row of brushes,if need be.black knight can make these with the eye holes at either end.
i will then have 2 or 3 sheets of jap matting,in the vertical position,this will be all for mechanical filter,as a good pre filter is crucial for the anoxic filter. after the brushes there will be a .7x.7 plastic sheet with 10mm holes in it to act as another diffuser.then i will have 12
bio census baskets 6 on the bottom,and 6 on top.the idea is 1 basket per adult fish.,this filter will have a few other tweaks,but this is only to do with design.and will not efect the filter.
as this filter will not work over night,my back up will be,50ltrs of mature crystal bio,at the end of the filter. and 50ltrs of mature bio in a shower.eventually i can take the bio out of the filter,and add more baskets.
the suck it and see part.flow rates,asked kevin novak about this,reply,as bigger pump as you can afford.?what does that mean.
i have a 12000lph pump,at the moment,outlet from shower is 6000lph,quiet a loss. so i think a pond turn over of once an hour will be ok.
by the way my pond is 2000gallons.so will buy a 20000lph pump.i can throttle it down if need be.you cant turn a pump up.
i think Ive covered every thing,and if anyone can find any genuine negatives about this system let us know.
my thanks to bob grinyer,for getting syd to our club,and thanks syd for the info on this system.
i have everything in place for this system.and will put it into use,after my holiday in September.

[mit]

Sounds good Sam, be good to have someone at the club with it in action, and to see how long it takes to get actual results. But from what Syd told us, it will take a while, which is probably why not many people have integrated it into their system.

Tim

[sam51]

no one want to discuss anoxic filters.

mit these should start kicking in at about 45days.

[Manky Sanke]

Right Sam, priorities sorted, you’re next. You want a discussion about anoxic filtration and some questions answered so let’s start with some basic background information for anyone looking in who doesn’t know:

The anoxic filtration system was invented by Dr Kevin Novak about twenty years ago. Whilst he was designing it and in the twenty years since then, he has studied every aspect of it including the molecular interactions between the media and water and also the various bugs that live in the baskets and how their biochemistry works under anoxic conditions. I first started to study the details of the system when I was asked to write an article on reducing nitrate about three years ago and I have been helping promote the system ever since. I sent one of the articles I wrote for Koi Carp to him to check it over to make sure I had understood the system correctly. Instead of slaughtering it, he liked it so much that he included it as an introduction to the system in the second edition of his book and has also had it republished in a couple of US magazines so, without blowing my own trumpet too hard, I think I can answer anything you might want to know and help take some of the work-load off of Kevin.

But enough of how I became involved, you want to know some answers. You say that a lot of people are “talking the talk but not walking the walk”; anoxic filtration is becoming more popular because it’s cheap and arguably the most natural filtration system imaginable. Couple that with the fact that the design is being given away for free and only needs cat litter, laterite and planting baskets and it isn’t surprising that more and more people are adding it to existing systems or even using it as the only filter on new ponds. I spend hours answering questions for people who are building the system or who have built it and want more information.

The reason why you have to be patient when asking him a question is that Kevin “Lord Lucan” Novak is very busy writing long and detailed replies to the questions he is asked about what goes on in the baskets and how they work. It’s annoying having to wait for an answer but contrast the detail you eventually get with the sales hype of media manufacturers who make wild claims, (only believed by the gullible), about how wonderful their latest media is but whenever someone questions these claims, they are never able to give a proper answer.

Obtaining the correct clay is vital. In the US, just about any cat litter will do because all the manufacturers use the same raw product. Over here, manufacturers seem to keep changing their products. I am testing the long-term viability of different cat litters to make sure that anything I recommend will last indefinitely but this is a slow process. I’m often asked if different media can be used instead of clay but one of the properties of clay is that it has what is known as very high cation exchange capability. I could explain that if you like but it might be simpler to just accept that it’s the property that attracts ammonia into the baskets, holds it there and allows plants to absorb it directly into their roots.

The particular type of clay is less important than its ability to remain granular and not become “sludgy”. It is vital that oxygen is present in the baskets but that it is at a very low level. It has to be above 0.5 mg/l so that nasty anaerobic bugs cannot live in the baskets but below 2 mg/L or the baskets will just become an ordinary conventional bio filter. Sludgy clay will certainly bugger up the oxygen level by making the whole basket an anaerobic mess.

A point that may interest you is that many of the new “wonder medias” that promise so much in the sales hype soon become anaerobic inside and become less and less efficient because of their inability to control the oxygen levels, so neither Kevin nor I make any apologies if finding the correct cat litter takes some effort . At least when you track down the right grade of clay that doesn’t become sludgy as soon as you put it in water, it will perform indefinitely rather than change its properties as many other miracle medias do. Email the manufacturers of some of the latest types of miracle media and ask them to tell you what will be the levels of oxygen inside, what bacteria will live in there and how will that change over time. You will either get a load of BS sales hype or the email equivalent of one of those blank stares that mean “I haven’t a clue what you are talking about?” But having the right bugs in your media is the most vital aspect of biological filtration otherwise what is the point of having it?

How much water will a basket filter? If ever a manufacturer tells you that their “Whizzy Gismo 4,000” filter will filter 4,000 gallons, they are either lying or they don’t know the first thing about biological filtration. If they say it is suitable for X number of fish; that is a little better but is still BS. Even relating a quantity of media to how much food you could then feed your fish shows a lack of understanding about bugs and how their actual environment dictates how they behave. With that in mind, when Kevin says you need about one basket per adult fish, it is pointless asking whether that means a 20” or a 30” fish. He is giving a guideline only. Neither he nor I will be drawn into being more specific than that. Much will depend on the basket and the actual pond environment. If you start with one basket per fish, that is a very generous allowance. If you didn’t really need as many as that, it won’t matter. The baskets won’t be as “full of bugs” as they could be. As the fish grow, they will produce more ammonia and this will support a larger population of the various types of bugs in the baskets. If you continued to grow the fish so that you ended up with a pond full of small dolphins, any filtration system would need to be expanded. With the anoxic system, all you would have to do is to make some more baskets and double stack them in the same way that you would have to put more media in, say, a Bakki shower. Except that adding a few more baskets to the anoxic pond would be very much cheaper.

You said in your post that the baskets take the nitrifying process one step further, that isn’t strictly true. Nitrification is a process where bacterial action first oxidises ammonia into nitrite and then a second bacterium further oxidises the nitrite into nitrate. Nitrification cannot take place in an anoxic environment, i.e. when the oxygen level is below 2 mg/L, as it is in the baskets. What anoxic baskets actually do is to do away with the nitrification process completely and to destroy the ammonia molecule either by direct absorption by plant roots in the basket or by complete metabolism by bacteria. The molecule is simply removed so it never gets a chance to be oxidised into nitrite or nitrate.

Kevin’s reply to your question about what size pump to use is pretty much true of filters in general. The bigger the pump, the quicker will be the turnover rate which, within reason, is a good thing. Within reason. I see on forums that there seems to be a competition as to who can empty the contents of the pond over their showers the quickest. I’d go along with that inasmuch that a two hour turnover is a good rate. A one hour turnover, in my opinion, is a bit quick but I wouldn’t argue with it. But, I saw on a forum, (can’t remember which, hope it wasn’t this one!), that someone was claiming to have achieved a 20 minute turnover. I can’t see any benefit in going that far but as long as you aren’t pumping your pond through the anoxic pond that quickly, Kevin’s answer is correct. The quicker the turnover the better.

That, I think, has answered all the general questions that you, and everyone else, asks. I was nearly out of time when I described anoxic filtration at your club talk so I had to be brief, if there is anything you want me to expand on, (or if anyone else wants to know about the system), over to you.

[sam51]

hi sid so will my proposed filter set work. where do you get the right clay, ive been looking at molar clay,this was used in tescos premium
cat litter,but they have now changed it,will this clay be ok
Moler Clay bonsai soil
£12.00
A new and incredible product ,this Moler clay is as hard as double line Akadama, drains well and is less than half the price. We have been using this soil for a number of years mixed with Akadama and Composted bark, in various quantities to make up an ideal and cheaper alternative to 100% Akadama soils.

Neutral and re-usuable if you dry it out and re-seive it.

Virtually dust free, paticle size is 2.5mm to 6mm.

[Manky Sanke]

Sam,

Just to make sure what you're describing and so that anyone else looking in can follow. Pump fed filtration is common in the US so this was how Kevin originally designed the system. (The diagrams are labelled figure 2 and 3 because they're plagiarised from an article on my own website - I don't think I'll get banned for that )






This is my suggested modification for those who would prefer a gravity fed filter.



As I see it, you are planning to use the second version but with rows of brushes and sheets of Jap-mat between the inlet pipe and the first basket to act as a mechanical filter. That would work but it will use up space in the anoxic pond. As I said in the text accompanying the diagram, it is a schematic to show the principle and, for clarity, details of prefiltration and a drain in the anoxic pond have been left out. I would prefer any form of prefilter such as a sieve, vortex or brush chamber to be external to the anoxic pond so that it could be cleaned or flushed to waste without losing water from the anoxic pond itself and this will also reduce settlement in it.

Having said that, if you don't have space for a separate prefilter, I can't see any reason why having a combined prefilter and anoxic pond wouldn't work, it will just be a bit harder to keep clean.

BUT, whilst I'm in favour of keeping ponds clean a small amount of silt in the anoxic pond isn't as bad as some may suppose. Think about this:

Cat amongst the pigeons statement
I'm not anti Bakki showers, got one (home made), love it. But try this for a bit of radical reasoning. Everyone with a Bakki or Bakki clone will tell you how wonderful they are and I agree. But, if you pump water over a shower and the water isn't perfectly clean, which is near impossible with any pond situation, the fish waste in it doesn't suddenly vanish, it just gets smashed up into pieces that are so small that they can never be mechanically filtered out by any other part of the filter system. So, what happens to it?

Simple, it gets broken down into ammonia and organic carbon compounds by heterotrophic bacteria. Some of these pieces will be "eaten" by bugs in the shower, most will get washed into the pond and get broken down there. QED Bakki lovers (including me) must agree that decomposition of fish waste by heterotrophic bugs under aerobic conditions is no bad thing. So if instead of smashing up fish waste in a Bakki, you allow some to gently settle in a settlement chamber or anoxic pond, as long as you clean settlement chambers or anoxic ponds often enough to make sure that the layer only ever gets to be a couple of millimeters thick so it can't become anaerobic, what's the difference?

Bakki showers and anoxic filtration with a good sized waterfall leading back to the main pond and are remarkably similar. The same facultative anaerobic bugs live inside the baskets as live inside denitrifying media in a shower. The same heterotrophic bugs gobble up the fish waste. And water sploshing about over tiers of media or rocks in a waterfall agitates bad gasses out and oxygen in.
Handbags anyone?

As for the media you've found. On another forum, a year or so ago, someone else tried bonsai molar clay and said initial tests with it looked promising. Later he posted that his nitrate level had almost disappeared. I haven't seen anything from him to say that the baskets had stopped working, and as I said, once you find a suitable clay that doesn't quickly become sludgy, there is no reason why it shouldn't last indefinitly. Give it a go.