hi all
I have done research on the building /buying of a biofilter and i am getting mixed responses on the subject. Many koi keepers are saying that bigger is better and then i get responses from outlets saying that i need a 50litre maximum sized drum/container which could be taken from the shelf.Please give me your views as i am considering building a 3 chamber filter (+_ 800 litres)and i do not want to go way overboard if it is total waste of time.If the views tend to go towards the large built biofilter i will appreciate if you can give me some guidance as in a drawing/picture of a good set-up ie the water flow through the system . I do not want to cut any corners either

Many thanks

Hi,

Will you be running an open/gravity or pressure system?
What pond volume are you talking about?

I agree with Pieter , we need some details.

secondly, forget that 50l of the shelf thing. It is Crap.

Give us your specs and then lets design something with the help of the experienced guys here.

thanks for the response and interest shown in trying to help me obtain a good balance in relation to filters come water quality . my pond is but a mere 8000 liters and my plan/intention is to run an open gravity filter(800 litres).at the moment i am running a 60litre pressure filter but am not having good results in my opinion.
regards

When I planned my ponds I was also a bit unsure about exactly what a bio-filter is. From the various posts on various forums one could deduct that it is an isolated container with whatever in it. It did not make sense to mee and due to the volumes I have there was a time that I visualised huge green tanks

Then I sat down and started looking back into my history as a river and stream fisherman and my days as a young boy fishing mud ponds and dams on the Highveld. I could remember crystal clear water and muddy brown water and I began to read up on water management.

Slowly but surely I began to understand that every edge, ridge, stone or plant in your system is a part of the bio-filter. My design is three interconnected ponds joined by two streams that was built to have steps in every 1.5 meters. Total of 18 meters of stream. I have large quarts lyke stones in the streams that forms the bed and the water runs over and under these. Many people told me that the rocks will become a problem for a number of reasons but watching the water run through the streams looked very natural to me and soon I noticed algae growing on some faces and when I lifted the rocks up there were black growth under it.

I paid an academic a decent fee for an evaluation of my system and he wrote a long report. His conclusion was that this system of mine is not really a few koiponds but rather a koi garden. He told me that the my waterfall and the streams alone has more bio-filter potensial than most "bio-filters" constructed in containers.

Here is one of the streams ... first tests to check for leaks ...



Here is the waterfall construction ...



Here is a shot of the bio system beginning to take hold ...



A shot of the streambed showing the algae taking hold ...



This is the veggie pond and really the engine room of my bio system. All water finally lands here and the waterflow is guided by bags of stone to allow more than enough time for all and any sediment to sink to the bottom.



This veggiepond looks a bit different today and contains kurpers, goldfish, mollies and platies. Each specie plays a vital roll in the system and the mollies and platies are specifically in here for the mosquitoes.

I think I will do a series of shots specifically focusing on the bio-filtering elements in my system.

My fish are growing and I can see the plants picking up as the bio-mass increases.

My advice would be to have as much as possible water in what you would consider your bio-filter. Depending on the space you have you could use a number big plastic boxes and pipe them to give you "up and down" flows through them. Adding a few bags of stone and as many plants as you can into them.

What I have learned is that the to look at a drum or a tank and say that is the bio-filter is not correct. Every piece of stone, every cascade and every plant that touches your water is an element of the overall bio-filter.

It is my personal opinion that most pond owners create their own nightmares by overstocking and then try and manage a small volume of water for too many fish. This leads to expensive and complex filtering and purifying.

I stocked my koiponds at a ratio of one fish per 1000 liters of water. I started of with 98 koi of between 5 and 7cm and today I have fish that are heading towards 30cm. It is great to see how they are growing into the pond space. I lost 4 fish in one year and I suspect dropsy in all 4 instances.

To me that fatality rate was more than acceptable. The veggie pond is a different story, I lost three nice Oscars due to an abnormal long cold spell and a few of the mollies and platies pegged also due to cold. I not concerned about that because it was expected, I am actually quite thrilled that the bulk of the mollies and platies survived the cold.

The kurpers are breeding like hell and I think I will start harvesting them by January February 2010. I like that too because that makes the veggie pond a good production unit.

I am the first to acknowledge that I do not have a purist system here but to me I have the joy of a system that runs almost on it's own and is as close as possible to natural.

Hope this has value to you.

gakes wrote:

thanks for the response and interest shown in trying to help me obtain a good balance in relation to filters come water quality . my pond is but a mere 8000 liters and my plan/intention is to run an open gravity filter(800 litres).at the moment i am running a 60litre pressure filter but am not having good results in my opinion.
regards

Hi im busy building my pond and im currently busy with the filters and housing Please could you tell me what filter brand and what filter media you are using as this should be more than sufficient for a 8000 litre pond

Also what sort of flow-rate do you have through the filter and how long has your pond been up and running ??

And lost question/s how many fish are in the pond and what size are they and what is your feeding routine?

Sorry for all the question but it just helps to understand why you see your current bio filter is falling short and why.


Cheers
Lee

thanks for your input Colyn but my operation is tiny compared to your operation . very informative though and i can surely use much of your ideas . thanks

hi Lee
i have a 60l 316L grade s/s manufactured filter drum , a 3 tier tray stack ,water supply/inlet 100mm from the bottom and outlet 100mm from the top ( 40mm inlet and oulet). 30 litre capacity bioballs , 10litre capacity small hair curlers . 3 layers akwa filter cloth. 15w pond medic uv.30mm venturi . 2x 25mm returns . .45kw pico badu speck pump .inlet split through filter and uv.flow rate through filter of +_3000 litres /hr measured with flow meter.the pond has been functioning since May 2006. stocked with 1x50cm ,1x38cm, 2x32cm, 6x18cm, 3x15cm, 11x10cm, 13 betw 5 & 8cm. ammonia reading =0mg/l ,nitrite reading =<0.3mg/l, ph reading 8-8.5 . all tests done regularly @ weekly intervals @ more or less the same time of day. water is not crystal clear and lots of hair algae. ps nitrate reading as tested with dipstrip = zero
regards

apologies Lee
feed aqua-nutro maintenance morning and late afternoon. weekend treat shelled shrimp, prawns and lettuce

Hi

I think your problem lies in your stocking density,I dont think your bio filter can cope and i dont think changing it is going to be a fix honestly, you have 37 fish in 8000 litre pond, thats around about 200 litres of water per fish , which is far less than adequate really.

Your reading surprise me as if they are all as specified why is it you wanting to change your bio filter ??

I know its probably not the answer you want to hear but i would suggest you sort out your stocking levels before you do anything else.

This just from my point of view but wait and see what the others say.

Cheers
Lee

hi Lee
one of the reasons for opting to go large gravity fed biofilter is that i have been plagued with hair/string algae and blanketweed . a tripple dose of viresco did absolutely nothing (followed preperation and dosage instructions to the t ) another reason is that i am using 24 kw of elec /day. this is due to running 2 x.45 kw badu pico pumps and aerators for both ponds. (changing to submersibles ).strangely enough my other pond half the size has the same filter setup but half the size and i have over 50 comets averaging 12cm ea which are very healthy , crystal clear water with similar water readings , no uv and only a thin layer of algae on the walls. i have posted my algae problem to this site last month but had a very poor response.

regards

Making the bio-filter bigger is not going to stop the algae.

The comet example is you clue ... they eat algae.

August to October is algae season and you need to learn to live with it I think. Pull the string algae out manually. You existing bio filter is now starting up and the plants are waking up from their winter sleep. In a few weeks the plants will consume the food that the algae live on and your bio-filter will be up to speed.

I think the biggest mistake pond owners make is to fiddle with existing bio-filters in Spring. This is the time of year that the bio-filter is at it's most vulnerable and very fragile. Any disturbance in filter material will kill off whatever survived the Winter.

My opinion is to leave everything alone till end of October when you can see the water is clearing up and then clean out sections at a time over the next month. Come November your ponds will be bristling with energy and your water should be clear.

But hey ... I am surely nou expert and merely speaks from experience and intense observation of each element in my system. The past few days the single sell algae is beginning to bloom and water clarity is taking a dive but the fish are healthy and the plants are showing lots of new growth.

Gakes
Colyn’s advice is sound; also keep an eye on the water parameters.
Now on your previous post regarding your UV:
You use a 15 watt UV am I correct? In my opinion manufacturers overstate the UV’s capabilities. A rule of thumb, I found somewhere, is to have at least 4 Watts per 1000 litres, 32 Watt in your case. On the other hand I don’t think that UV will necessarily solve your blanket weed problem. Now here I stand exposed and await to be ostracised by others, let’s hear their opinion!
I followed your post on your UV and your discussion with Marius. It seems as if your installation and operation is in order. Now I wonder; isn’t one UV very much like the other and even use the same components? Maybe have the components tested to be in spec? The lifetime of a globe should be eight to twelve months.
As a matter of interest I looked at the price of UV’s and replacement globes; as an example a 30 Watt Ultra Zap cost in the region of R800 and the globe some R300. You could have replaced your UV about three times with all the globes you have bought. In your position; I will take the UV back to the supplier, me and my grandchildren will then throw a tantrum until they refund me or supply an alternative make.

You are right Jan ... UV does nothing for blanketweed ... UV only helps for the single cell algae ... the stuff that makes your water turn into peasoup

Fish eats the string algae ... especially goldfish, vleikurpers and grass carp.

When the algae picks up I cut the feeding seriously. This forces all the fish to start browsing

hi David
come up with any design propositions yet ?
regards

hi all
why is it that one does not find any proffessional diy bio filter plans online in the biofilter sites or is there a special site that i am not finding?
regards

Hi,
The answer is in your question - "professional sites".

The "experts" and professionals make a living from distributing advice and information - so they charge for it. Nothing wrong with that.

Another reason is that there are many ways to design and make a koi pond filter system. Yes, you can purchase a ready made one but there are limitations to these. Further, people tend to latch onto one design and then tell the world this is the ONLY way a filter system should be done. This is not true - there are many clever, simple designs out there that WORK.

In designing a filter system there are some basic principals that apply to ALL filters and bioconverters. Learn these basics and you will soon find a design you are comfortable with and if necessary you can build it yourself.

Regards,
Chris

Hi Gakes
Did you see this concept?

http://www.happykoi.co.za/filtration/build_your_own_filter.htm

thanks Guys, really appreciate it . i have started my own design using benchmarks and hints from many sources and don't think i am far off from the real thing to suit my needs , building the system with 12 mm marine ply and will be coating inside and outside with 3 layers fibreglass and final coat gel coat . all info that i receive from this sight just adds value to my project . thanks once again.
regards

hi all
i have completed my filtration project and completed installation 24/10/09. i am really over the moon with results. 6days later i had a sparkling pond and has remained that way since.i would like to share this little project (if it is welcomed) with those who are experiencing what i initially experienced (blanketweed/hair algae/pea soup for months.[hell]no other way of explaining this plague).if there are interested parties i will take some pictures and am more than willing to go through the exercise on this site step by step.all boils down to a decent filtration system.(bigger is better)
keep well all
thanks for this site

Awesome man!!!!!

Glad you managed to sort it out.

Did you take pics along the way?

If you did then please post them in another thread and also give us a description and breakdown of your concept and how it works.

Another huge positive from doing this is that you now understand the concepts behind it all and you also undrstand your system and how to maintain it.