recycle

I do agree you got higher stocking levels at a farm, but I still think the gallons per inch iof fish in the water body would be significantly greater than a home aquarium, I would hope so.

I am going to try this so, it needs to be efficient small and cheap to run as well as having an improved water retention rate.

From the research I have done, this filtration would remove things like parasites and cysts if the mm of sand media is small enough, bye bye free swimming Ich for the most part, flukes and so on.

I care not of the biological filtration of the larger gravel, its for mechanical purposes only and its location is easily accesable for maint, very easy to clean compaired to foam. Rinse.
The water in a trickle system should work, in this setup a pressurised system would probably eventually leak, the water spends a long time in the media, many many times longer than in a conventional filter, apart from the on off ones FX5 ect, but still longer than them also
Then on to the plants for another level of filtering (More research needed for this part but I am hopeful for the first two stages.

Another concern is the longevity of a biosand, I have not looked into yet, if this is once a year or something I will be very happy indeed.

This can be augmented depending on results and available plants or ideas.

Above all this has to be practical and efficient and cheap using as little electricity as possible, when we talk mud and other things it starts to become infinately more hassle and less pratcival to the average keeper with limited space and resources.

We can get plants and sand quite handy and at a price I can agree with.

Enjoy the beers matey, earned I am sure:) Don't mind me, am very tired.


Mark

Hey guys, just a quick note....I didn't see any shooting down of any ideas: I see ideas being passed between people.....and that is what science is all about (and this is science).

On the word 'filtration', Biological Filtration is a bit of a misleading term if were to rigorously review terminology.

In all of this there is a lot of theory, but the theory can only be effectively applied if we have gained the knowldege of how we can use that theory to predict outcomes.

There are still many unkowns, and, not wishing to get too technical, much of the theory is based upon assumptions that may or may not apply the interface between water and biological substrate.

Chemistry and physics of water/solid faces is very much different to normal bulk phase chemistry....eg we often see pH being incorrectly described as the negative log of the hydrogen ion concentration (and we all use it); but fortunately in the bulk body of water the concentration of water so so much greater than acid, hence pH approximates to a measure of hydrogen ion concentration.
That may not be case at an interface, organisms at that interface will react to the localised pH....the choice of substrate may affect that localised interface.
Moreover, the water/filter substrate interface can be exploited in terms of localised pH, localised electrostatic forces etc (I hope I haven't gone too technical there).

Developing a system takes time and experimentation. I was working on a re-cycle system for the public aquarium that I was curator at....and in the end decided on air-powered undergravel filtration for all tanks (including Marines). My involvement with fish farms was imited to developing a feed system for them.....but the idea of a fish was not necessarily to keep the fish alive for upteen years.

ian

Itwill take time, and the outcome far from certain, it is an experiment after all. Using facts n data to prove something won't work is shooting it down, just a term and nothing to do anything unfriend l should think.
I just wasn't happy with the whys, or the lack of after reading my eyes out.
What I hadn't figured is the man had had a few beers, it was very late, so I totally understand. Was knackered myself

It is an experiment and the outcome is far from certain. I have to put it out there again that the biosand is only stage 2 out of a three or possibly 4 stage process system, also, if I can introduce something into the sand to further my results, bacteria, some sort of crazy sand worm, I have no idea, I would be willing to try that also, lots of research needed on my part.


A pressureised system does not, even with a sand filter, work the samy way either, one of the problems with pressurised systems is particle penetration, lets face it, particles go right through a conventional filter becuse of the pressure. Media particle size is important for 2 reasons, obviously filtration, and flow rate, a careful balance is needed, which can be attained by test test test. The schmutzdecke film created from this trickly system has important properties for filtering out nasties I think

I can't see a conventional filter providing you with drinking water from a raw water source, the biosand filter does work in that respect, so I am taking a very old proven technique and pimping it up:), if drinkable water is an end result of my efforts that can go right back into the rank, again, plant filtration will occur last before it goes back into the tank.

Biosand filtration
www.biosandfilter.org/biosandfilter/index.php/item/320

Bring on th technical Ian, cant I I understand it all but I wish I had your understanding of this, I'd benefit no end.

Mark

Reading a bit more on this, there's Miicrobiological filtration too as well as Biological and physical.
Some will understand this I ma sure, the microbiological part of the filtration, but not me:)
Have a read.

EDIT, read a bit : A copied line : "Microbiological and biological (for example, bacteria, protozoa, viruses, helminths and higher organisms"


www.biosandfilter.org/biosandfilter/index.php/item/297


Mark

EDIT: have a look at a larger particle filter, my planned filter will hold water longer.

I'd advise re-readimng that link .....

it says....but it itself is not really correct if it is splitting hairs...


QUOTE FROM the above link...
" There are 3 types of water quality features House and Reed, 1997 [ref 01]):

Physical (for example, colour, pH, taste, odour, temperature and turbidity)
Chemical (for example, arsenic, fluoride, chloride, conductivity, dissolved oxygen, iron, manganese, nitrate, nitrite, sulphates, pesticides and heavy metals)
Microbiological and biological (for example, bacteria, protozoa, viruses, helminths and higher organisms)
"

It's the water quality features they are on about.
A microbiological filter system is a biological filter system. Maybe it should really be called a biochemical filter.

Looking at their list quoted above, I see 'conductivity' under 'Chemical' yet pH, Taste, Odour under 'Physical'.. That is odd, irrespective of which class they fit into they should all be in the same classification (pH, conductivity, odour, colour, taste are all physical effects or manifests of the chemistry of the water)

I shouldn't have gone to that site to have a look as now I'm tempted to review it.

....I've just had a quick read.....well, not of it but of the reference list. It is good that it has referenced some journals, but some of the basic facts that were know about years are cited to quite recent publications.....and that makes me suspicious (ie have they simply read reviews and used them as supporting references? that is not a good thing to do unless they are cited to be 'further reading')

I have to re read everyting Ian:)

Regardless of the way htey class certain things on it I am looking at the effects obtained from using this method. I will not pretend to know exactly what I am looking for, nor do I to completely understand the entiree peocess by which the water is filtrated.

Lacking a lot of knowledge in certain areas leaves me with having to look at results already obtained from existing filtration systems, and then try to understand the process and see how this can be adapted to my requirements, and obviously these must be pratcical and cost effective to implement.

Throw me a bone here, gimme something to work with:)

I especially like hte removal of viruses and bacteria, something our filters dont do.


Mark

I must say that classification of methods is quite important when reading something that is under an umbrella of 'Science'......there are hints within writings that often tell us if the author knows what he/she is talking about or whether or not they have simply copied something from somewhere else and mis=placed the context.

The link is profoundly about water treatment for human useage. Hence, it has to be of standard that exceeds what is required for a fish tank.

Fish are quie happy to live in water with a reasonably high bacterial count, low levels of ICH, worms, nematodes etc etc......but it would be unacceptable to have water for human consumption with such things.

SO: maybe no ones needs to go to the n-th degree to get the water 99.99% recycled for fish.
One would als end up in with world of diminishing returns.....a stage is reqched where the more effort that is put in, the returns just don't increase.

I see the notion of evaporation in the Link.....how expensive would that be? even though it claims very high effectiveness. Not an option on a small scale.

For a fish tank, it is not required to rid the water of all bacteria....but the system must not allow a biological overload. Even with our so called 'benefiial' bacteria such as nitrosofying bacteria, there can come a stage when the oxygen demand of them is so high that fish will also suffer.

As a generalisation, fish in small less open systems (eg puddle fishes, pond fishes) may tolerate amazingly poor water quality; fishes from small very open systems (eg hill streams) are having a constant supply of fresh almost rainwater being supplied. (an open system is one which has exchanges with its surrounds).
What about the sea? although it is not a closed system (feshwater constantly being churned into it with increasing the salinity of the sea.....it is vast and offers ample scope for effective recycling.

In the biological world, competition is important....and bacteria are also subject to competition for food, space and oxygen/sulphur/or whatever they require as their 'end electron-acceptor' in respiration. A balanced and established microbial system is important in fish keeping (especially in a fairly closed system as we get in a fish tank).
That balance needs to be kept in a recycling schema.

No, I'm not gonna spend ages writing up how the various filtration systems work as I need to feed my animals, and that takes about an hour or so to do, and it's bank holiday....so I'm possibly off to any sales.

by the way, tesco have some good perspex (or good quality clear polystyrene anyway) storage jars in a the moment at a good price...ieall for mini-scale chambers. (I've already bought a good few of them).

I just meant classification made no difference to me, the unlearned one, I couldn't tell when it was wrong:) Bette if I focus on what I can work with.

Thanks Ian for taking the time on your precious time off, I really appreciate it. Your last post is going to have me off reading again, coming back, reading ect.

Evaporation I hadn;t considered at all, cheers. The mechanical gravel stage will be open to air and not submerged, aeration should be performed well by this stage before the water travels past this into the sand, so constant trickly of nicely aerated water will need to be constant to keep the Biosand alive.

There are things that happen in the filter and possible problems I am not aware of yet, part of the enjoyment though:)

For the purpose of my project, I have looked at a section of piping, 6" diameter, 3 foot long, the tank it will be filtering is quite small, 90 litres. I will start the cycle with no fish, just food, and see how it goes for a month, tests and so on and see how fish get on after that, when I have some kind of idea of hte effectiveness of the filter I cna add the plants to the setup and again, wait and see the results.

I wil have a gander in Tesco at a perspex container for stage one, I want it to be transperent so I can see if it needs cleaning, if this part gets clocked, the biosand dies.


Many thanks matey, enjoy the sales.


mark

I did enjoy the sales....I got myself a nice jacket that was over a thousand euor dropped to 80; some boots from 180 euro down to 60; and I got myself some glasses so now I can actually see the my laptop keyboard in-focus.

I'll be back to this thread later maybe; I need to cook a nice hot Madras curry to get the old brain cells working again.

That was some good hunting indeed.

igmillichip wrote:

and I got myself some glasses so now I can actually see the my laptop keyboard in-focus.

Tell me about it, still have not gotten glasses, I'm needing them for years and she is always telling me off as I try to peer and squint in vain, saying "they're still good, I can read"

Mark

This is an interesting read on an Arsenic Biosand filter ABSF, a project run by MIT & Stanford people in Nepal.

aquadoc.typepad.com/files/mit-arsenic-biosand-filter.pdf

Very clever indeed. intersting design and seeming positive results obtained, has me thinking how this can be applied with different long life media to remove certain unwanted elements from the water.


mark

Was just watching on Euronews.

New filtering system for filtering drinking water & doing a great job of killing bacteria.


Made from Silver and cotton and 20v applied to the membrane for want of a better word, apparently does a great job of nuking bacteria. Haven't as yet found any links but this seems like a very cheap way to filter out bacteria from water. The research is being completed, tested more n so on I guess but it looks goood. NASA use silver in their filtering systems for its anti bacterial properties, the added volts must increase effectiveness or something, I missed the "scientific" part of the report at the start:)


Mark

That's quite a long PDF file...170 pages. So I'll be while reading that.

Looks like my old friend Iron could be important in the filter sand filter.

I didn't see the NASA filter report, silver has been used as an antibac for a long time (eg silver nitrate for newborn babies eyes)
It is the 20V that interests me here......maybe that is simply to get the right redox potential. ?
I'll see if there is exact and finer details to this nasa filter.

igmillichip wrote:

Looks like my old friend Iron could be important in the filter sand filter.

I didn't see the NASA filter report, silver has been used as an antibac for a long time (eg silver nitrate for newborn babies eyes)
It is the 20V that interests me here......maybe that is simply to get the right redox potential. ?
I'll see if there is exact and finer details to this nasa filter.

Bah! I thought that the NASA thing was something new. How come these news reports are 30 years out of date.?

From what I can make out, the NASA filter is the old colloidal silver thing (but.....they may have come up with something new that is a big secret !!).

Mark. wrote:

This is an interesting read on an Arsenic Biosand filter ABSF, a project run by MIT & Stanford people in Nepal.

aquadoc.typepad.com/files/mit-arsenic-biosand-filter.pdf

Very clever indeed. intersting design and seeming positive results obtained, has me thinking how this can be applied with different long life media to remove certain unwanted elements from the water.


mark

That is a lot of reading and a lot of it just keeps repeating itself. You get half way through it just to find the first filters were decommissioned.
If you are going to read this start at about page 80 or so.

The end results depend on the pH of the ground water, but they dont mention what the pH was in each area tested.
Flow rates are also very low, averaging 29L/H. But this could be increased with a bit of tinkering. Maybe given a decent head height of water to force it through the 1mm sand would increase the flow rate.
Some tests show it didn't remove bacteria (H2S).
No back washing so it need to be cleaned every month to prevent channeling..

It seems to do a very good job of removing arsenic. But i cant see myself setting one up for my aquariums.
If you want to really clean water try passing it through a membrane that removes particles down to 0.02 micrometers (i think its 0.02 for bacteria).

@ Ian, what is Darcy flux in relation to flow rates?

Platy, you got further than I did on that.

Darcy flux? is the paper mentioning that?
Ummmm....that is an interesting thing.
The equations seem to work for most applications, but the equations seem to not be based upon a direct theory of the process (ie someone observes something, and an equation picked off-the-shelf so happens to fit what is observed....well, that is my take on it anyway).
The equations predicting the outcome has some limitations at some extremes...probably because it is not a proper theoretical relationalship.

It's not really in my realms, but it has to do with a relationship between movement of water (or other fluid) through a porous substance; the decrease in driving pressure; and the viscosity of the fluid/liquid.

Someone in geophysics would probably deal more with darcy flux.

ian

No Ian the NASA thing is not new as you've said, the report touched on the NASA technique and how to develope this with better results on a larger scale as the NASA one doesn't need to be filtering rancid water to begin with, it was the plain old water filter they were testing on that had the silver with 20v running through it, I tried to find something on it as it was on euronews, on a report on dwindling drinkable freshwater supplies globally.

As for the other article, both yourself and Darren would make more sense of it than I, I just try to gather as much as a wide a perspective as I can due to my lack of knowledge and experience and as a result of this thread I know and understand a hell of a lot more than when before, but still not enough:)


Ian if you could maybe offer ideas on how the 20v added to the silver gauze might better remove things like Cholera ect, currently the report stated it was 98% successful as I haven't a clue why but find that bit very interesting myself



Mark

Mark. wrote:

No Ian the NASA thing is not new as you've said, the report touched on the NASA technique and how to develope this with better results on a larger scale as the NASA one doesn't need to be filtering rancid water to begin with, it was the plain old water filter they were testing on that had the silver with 20v running through it, I tried to find something on it as it was on euronews, on a report on dwindling drinkable freshwater supplies globally.

As for the other article, both yourself and Darren would make more sense of it than I, I just try to gather as much as a wide a perspective as I can due to my lack of knowledge and experience and as a result of this thread I know and understand a hell of a lot more than when before, but still not enough:)


Ian if you could maybe offer ideas on how the 20v added to the silver gauze might better remove things like Cholera ect, currently the report stated it was 98% successful as I haven't a clue why but find that bit very interesting myself



Mark

In guessing that the 20 volts is merely to make a silver colloid, then the 20v as an exact figure is probaly not relevant to the type of microbes that this will kill. It may be a value that has been found to be optimal for a given piece of silver in making colloidal silver.
As an anti-bac, silver works by different biochemical processes.....some organisms would be more or less susceptible to damage by those processes.
As an analogy, penicilin antibiotics work by disrupting the walls of bacteria where the wall is heavily dependent upon peptidoglycan......so if a certain species of bacteria does not rely on peptidoglycan for its cell wall then penicilin has little effect (notwithstanding the acquired resistance that bacteria mutants can show). Other antibiotics might work on something different (such as bacterial ribosomes involved in protein synthesis)...and again, there will be a species-specific tolerance there as well.
I would not remember off-hand the specific organisms that show increased immunity to the silver colloids.
I have, somewhere, a document on the construction of silver colloidal generators.

ian

igmillichip wrote:

Platy, you got further than I did on that.

Darcy flux? is the paper mentioning that?
Ummmm....that is an interesting thing.
The equations seem to work for most applications, but the equations seem to not be based upon a direct theory of the process (ie someone observes something, and an equation picked off-the-shelf so happens to fit what is observed....well, that is my take on it anyway).
The equations predicting the outcome has some limitations at some extremes...probably because it is not a proper theoretical relationalship.

It's not really in my realms, but it has to do with a relationship between movement of water (or other fluid) through a porous substance; the decrease in driving pressure; and the viscosity of the fluid/liquid.

Someone in geophysics would probably deal more with darcy flux.

ian

I found it Ian, although in an earlier page than i expected and it pretty much explains it. I must have breezed past it not noticing it.
It comes up again later in the text but without any hint of explanation so it lost me.

"Darcy's law governs the flow rate of the filter. That is, the filter flow rate is proportional to the water level above the outlet pipe. The higher the water level, the higher the hydraulic head, which leads to higher Darcy flux through the sand, which in turn means higher flow rate".
Section 7 page 79.

Thanks Ian.

P.S. i should mention the test done are very vague, it could be a month before the water is tested after samples were taken and temperatures ranging from 10c-35c. This would have an effect on the bacteria count and the delay in testing would give false results for arsenic since the arsenic would settle at the bottom of the test tube.