So Gents ....

I AM going the DIY route, i am also trying to go low elec consumption and i am going bead bed filter (go easy on me SF)

so comments from the DIY guru's and filtration guru's please hell even the not so guru's i am interested in your opinions

chamber 1 fed by the 110mm bottom drain in the pond
est vol is about 50L
water enters at the base and overflows through 3 x 50mm holes
this is the traditional "settlement" chamber and will have a drain on it, i am also looking at ways to incorporate a sieve of types in order to trap leaves should they sink and not get caught by the skimmer .. any houghts?

Chamber 2 fed at the base by 3x 50mm drains from the settlement chamber, this is the bead bed filter which will have i guess about 30 to 40 L of K1 material although i am toying with injection mould beads which are about 3mm in diam and float well. and i can get them mahala.... the top of this chamber is a grid anout 1mm in diameter, this is the final mechanical filtration before it overflows into the biological chamber

chamber 2 and 3 are about 50L

chamber 3 has about 35L of K1 material, constantly aerated with air fed through the tubes shown below.

the second chamber is "cleaned" by opening the valve and re-directing the air from the 3rd chamber to the second .... exactly the same as commercial products.

the water exits the base of the third chamber, is routed through 2 x UV lights and into a fairly elaborate series of vegetation chambers and waterfalls

now for some pics

How many litres is your pond ?

Hi Neil
let me try
I dont know how big your pond is and also how mant fish s cannot comment on the size of this.

I would allow the flow from chamber 2 to 3 to also go down to the bottom, and then I would exit from the top of chamber no 3.
I think you will do better if you slope your floors to be able to clean properly.
I would place alfa grog in chamber no 3.and only aerate chamber 2.

I think 3 chambers is not enough as 1 is lost being a sediment chamber I am concerned that you will get sediment in chamber no 2.

thank you for the early replies gents

Ok the pond is relatively small by some peoples standards, but is the largest i can put in at this stage, i estimate it to be in the order or 9000 - 10 000L

Fish, well i am extremely patient in stocking time, i am after fewer, but spectacular fish. I like to think i put the fish's needs first so would definately not purposly overstock.

@Neville, thanks for the help so far, maybe i was not clear in my post so let me explain further.

the glass look is simply schematic at this stage and most likely i will opt for 2 x 50L bins for chambers 2 and 3 and a larger perhaps 100L bin for chamber 1.

All three chambers will have bottom drains installed with valves for "easy" cleaning.

Chamber 1 is a traditional settlement chamber, i thought of making this part of the pond as in a brick and mortal chamber but fail to see how one could effectively clean this so have opted for something that i think is easier to work in ... but i may well be incorrect.

Chamber 2 is the traditional mechanical filtration, it equates to a sand filter or a bead bed filter, there will naturally be a build up of waste in this chamber and will be designed for easy cleaning. Logic with this one is that water enters the base, and has to move through the bean bed before moving through to chamber 3 (thus filtering out the solids) this chamber will only be aerated 2 to 3 times a week when the filter is cleaned, the logic being that this aeration will breaak up the bead bed.

Chamber 3 is the biological filter, and will be aerated at all times in order to provide an oxygen rich environment for the bacteria to do their thing in the nitrogen cycle.....

I think your design is on the right track.
Agree with Neville about floor slope and top to bottom flow. The top to bottom flow will allow the cleaning of one chamber at a time without draining any others.
Because of the ease of cleaning I will personally use K1 (or the cheaper generic) as you stated.
I assume you are aiming for a gravity fed pump return filter system, please elaborate.
Following some observations;
1. Aim for 3 to 5% of pond volume for your settlement chamber.
2. Have the bottom drain pipe enter the settlement chamber as a stand pipe protruding above floor level with the end some 40 cm plus below water level.
3. The filter media in chamber 2 (mechanical) need to form a static plug to remove solids and thus the capacity of this chamber is not that critical. Nevertheless I think that 50 litre might be too small.
4. In the biological chamber, bear in mind that 50 litre aerated K1 has the capacity to filter 250 gram of food waste per day. Your intended 35 litre in the biological chamber will thus, at feeding say 1% of total Koi body weight, be able to support 17,5 kg of total Koi weight in your pond. This is one Jumbo fish.
5. The volume of your biological filter is important in that you should aim for between 30 to 70% of the chamber capacity for your aerated K1 media.
6. When deciding the diameter of pipes between chambers, bear in mind that the diameter of one 110 mm pipe is roughly the same as that of five 50 mm pipes.
7. Consider to cap and slot the in and outflow pipes between chambers and on drains to stop media from going wandering. This will also alleviate the need of grids in chambers.
8. If the chamber is below ground level you will need some means to empty these (maybe use the pump). Above or on ground level gravity will do the job.
For what that was worth.

Thanks Jan, absolutely great feedback, thank you!

seems i need to rethink the configuration in order to increase the biological filter .... as i certainly want more that one fish....

in terms of the system as a whole, i was thinking about gravity feeding the settlement chamber, and then gravity feeding the remaining two chambers with a pump attached to the third chamber feeding the planted chamber. however given that the boilogical chambe needs to be much larger i may look at putting the pump between chamber 2 and 3 and letting chamber 3 gravity feed the plant chamber..... but then where do i put the UV lights? this is not simple (plus got to make it look good so that SWAMBO does not get too upset)

Show us some shots of where you plan to do the stuff

Hi,

Be careful of the gravity fed pipes. Especially the 3 x 50mm may not be enough.

What size pump will you have on the system?

It's very important to match the pump to the pond volume and match the gravity fed pipes to the pump volume. You get much less water through gravity fed pipes than you do through pipes under prresure.

Chris

I will rethink the 50mm connections, possibly replace this with 2 x 110mm connections.

the pump i have in mind is a marine pump.... trying to get a low watt pump and they have some good options, what turnover should i be aiming at ? I was thinking in the order or 5000Lph, am i completely worng?



this is the enterance to the house the gaurage is on the right and the main door on the left, this pic was taken in Dec before we moved in, since the pic, all vegetation has been removed

Blue lines outline the approximate shape of the pond the red area indicates part of the waterfall arrangement



this is the other side of the pond with the filtration and beginning of the waterfall, with the now much larger estimated biological filter gravity feeding the plant tank

Is the area big enough to accommodate a 10000 litre pond, what are the dimensions?
In any case on a 10000 litre pond a K1 bio filter of 250 litres should be sufficient. This translates to a maximum of 175 litre K1 which should support 87,5 kg Koi at 1% feed rate i.e.10 good sized ones. On the other hand if you want to be safe go bigger, we all tend to overstock.
Turnover should ideally be the total pond volume in one hour.
The pump at the end of the line followed by the UV will still do just fine. Bearing in mind that you plan a vegetation chamber and what can happen there, rather over speck than under speck the UV!
Following on to Chris’ point on pipe diameter, consider too add a surface skimmer to also feed the settlement chamber and thereafter at least two 110 mm pipes leading between chambers.
As from the energy consumption angle; consider a low energy pump, something in the range of 15000 l/h plus, these are not cheap but, in my opinion, worth the expense in the long run. As you will be aerating the system you may want to consider expanding the aeration to include an airlift circulation system.
That is my pennies worth for now.
PS where you do you stay?

Thanks Jan

Ja look i based the 9000L on an estimate of 1.5m deep, 3m long and 2m wide which i agree may be optemistic, lets put it this way the pond will be as big as it can be and my best guess at this stage is 9000L

I was hoping to have about 8 to 10 good sized Koi in the pond eventually, it will form part of an enterance feature which aside from providing me with endless hours of enjoyment will also hopefully increase the value of the house should i ever sell.

if i pumped from the mechanical filter to the biological filter via a UV would this be ok???

I have 2 UV filters which have been given to me, my plan was to put both of them in and run them when required.

I am not sure i follow your comment about the vegetation chamber, i thought this was beneficial.... are there possible problems with these ???

I have planned a skimmer, but didnt put it in the design - doff moment. i am still baffeled as to how this works with the bottom drain, surely the pressure from the bottom drain moves water into the settlement chamber faster than surfce skimming cn ??

I am looking at a marine pump which does 8000L per hour and comsumes about 60watts .... sounds pretty good to me ! any comments or suggestions on other pump?

When you say airlift circulation are you referring to an air stone above the bottom drain? as i am considering this option

I am based in douglasdale, JHB

Neil
Just rethink along the lines of using a 3 bagg sand filter coupled to a ,35Kw pump and a 30 or 40Lt Ulrazap bioifilter filled with alfagrog, and then a 30Watt UV sterilaser. This over a small waterfall (remember the noise).
Maybe keep the waterfall small and add a small air pump.

Ok I know this sounds a bit small on the pump insofar as the sand filter is concerned but if you make use of air to clean your sandfilter you dont need all that volume of water, and a smaller pump will do fine. It is turnover rate you have to look at and a rate of 50% of pond volume per hour will suffice.

It will be very tidy, take up little space and you will have very clear and good quality water.

This system could also be installed in one day. and all the costs are known beforehand.

A 10000Lt pond is not a small pond and I bet that a year from now you will be overstocked.

1 Cub meter is 1000 Lt so if you build your pond 1,7 meters deep (say 1,2 meter down and 500mm (Exra 200 for space) up, then you need roughly an area of 2,5 x 3 Meters inside the walls.

What do you think Chris.

hi Neville,

I am a bit confused by your last post, one of the earlier posts said that my planned 50L DIY reactor with K1 madia in it for the bio filter would only support 1 or 2 large Koi in terms of processing the waste produced. Is the Ultrazap bioball setup that much more effective that one could reduce this size to 40L from the last suggestion of 200L of K1 material?

I understand the affinity people have to sand filters but i want to go bead bed mechanical filter firstly for the ease of cleaning (with air) and secondly is the long term power consumption, if i go bead bed i dont need hectic pressure therefore i can go for a more env friendly pump

Een ding wat ek goed weet ... as jy over and under en plante en beads wil gaan moet jy seker maak jy het spasie. Ek het myself sleg in voet geskiet want die jaar toe groei die visse dat dit bars en skielik toe vou my meganiese filtreer kant.

Hi neil here is a copy and paste article

I am very sure that the 40Lt ultrazap filled with this will be more than adequite biofiltration for your pond and will allow for some overstocking.
It is not so much the volume of the filter box but the area of the bio Media that is of the essence here.
Just remember your sandfilter will also add to the bio filtration. A clean sand filter adds very little extra presure to a system. and the ultrazap wont add any.
Sand filters are not difficult to clean if the correct procedure is followed.

Copy and paste
When a Pond Filter is combined with an UVC (ultra violet clarifier) in a fish pond the result is clean clear healthy pond water in which fish grow to their full potential for that particular pond. The filter purifies the water and the UVC clarifies or clears the water by killing suspended algae responsible for making pond water murky.





The secret to cleaning the water in a pond biofilter is to have enough biomedium inside the filter so that large populations of cleansing bacteria can live and thrive on the biomedium surface.


Many types of biomedia are to be found in pond filters the most common of which are a variety of plastic tubes or balls. 1 Litre of Alfagrog (approx 500gm) is sufficient to purify 1,000 litres of pond water with normal stocking density. If you have a high stocking density then increase the amount to 2 litres per 1000 litres of pond water.
The disadvantage of using plastic items is that a large volume of these is required to create sufficient surface on which the bacteria can grow because the plastic is smooth at the surface and does not have a large specific surface area (ie ratio of area to volume). In practice this means the size of the filter box to hold the biomedium gets significantly larger as the pond volume increases. And of course the bigger the filter box the higher the cost.
The cost and performance of any biofilter can be reduced by using more efficient biomedia types and by far the best low cost biomedium in my experience is a product from the UK called Alfagrog. This product was developed for use in commercial aquaculture operations.
Alfagrog is a fused ceramic product full of small holes which creates a very large specific surface area (ie area of surface relative to volume of the biomedium). In simple terms this means large colonies of bacteria can be grown on small volumes of biomedia. For example 1 litre of Alfagrog will do the same purification job as 40 litres of plastic tubes or balls. This thus means a very small filter box is all that is needed to create an effective pond filter.
Alfagrog can also be mixed with existing filter biomedia such as plastic tubes to create extra filtration capacity to allow for fish growth or higher fish stocking densities. Just mix the Alfagrog with the other biomedia in use.
SSA (specific surface area) in sq.m. per litre of different pond filter biomedia for a home made pond filter is shown below. A high number is best! If an SSA is 1 then theoretically an SSA of 8 will provide surface to hold 8 times as many bacteria inside a pond filter. The same relationship applies to litres of biomedia.
Alfagrog 45 to 100 depending on particle size
Ceramic Rings 8
Lava Rock 8
Plastic Foam 2.5

It is clear from the above that alfagrog is good

This has been said by a few guys, I would keep all the all pipes in the filter 110mm, the trouble by far out ways the extra expense.

neil h wrote:

Chamber 2 fed at the base by 3x 50mm drains from the settlement chamber

Hi Neil

Please remember that this is just my feelings on the filtration and that is what I would considder doing in this case.

I think cost wise there wont be too much in it, just a much tydier system for me, specially at the front door. You could place some plants in your waterfall to take care of nitrates.

Try also to do your piping such that you have some water returning to the pond to create a current for your fish as well as circulation. (anticlockwise remember)

Let us just waite and see what Chris has to say. After all he knows best about this.

Hi niel h
I would place 50mm bottom drains for ease of cleaning in each of the filter chambers. You couple them all into one manifold including the water flow back to the pond and you can operate this with one pump by using a valve placement in each line.