Hi all,

I am quite new to koi and would like to find out a few things:

Are leaf skimmers connected to the bottom drain or pump? Are fish not sucked into the leaf skimmer? Do you add a mesh or something?

How do protein skimmers work and their purpose?

I have a settlement chamber next to my pond. Both my bottom drain pipe and skimmer runs into this chamber. In between the 'inlets' and output to my pump I have a Matala sheet so keep the big 'badies' on the one side. On the pump pipe I use a Matala pre-filter of higher density to try and keep most of the smaller debri out before it reach my pump. Once a week I 'vacuum' the primary side of the chamber (uses less water than draining the chamber. Simple job. Switch pump off and take sheet out to clean. In the meantime everything settles and after cleaning sheet you can vacuum chamber)
I use a 'drain box' from builder’s warehouse as a leaf skimmer. About R45. The holes are big enough to catch the leafs and water flow seems to be slow enough not sucking fish in. Only problem is that it tends to suck food in before it is eaten. I have spotted an area in my pond to add food that takes longer before it reaches the leaf catcher.
Some people connect the bottom drain and skimmer via the same pipe to the pump and rely on the pump basket to catch the large leaves.
I don’t use a protein skimmer because I believe that you won’t have protein on water once properties settle. When I was in SA last month I had protein on water after adding 90kg of salt after then I fitted my new filter media. About a week later the foam went away.
My believe is not to interfere with nature. Most things will settle in time but this does not mean that you must sit back with a beer and relax. VERY important to check water parameters and be on the look out for any problems with fish. To do it in the proper way might not always be easy but then again it is a great hobby and cleaning the pond, giving medicine and and and should be a pleasure not a pain where ever.
You can view the setup under 'All your questions about filtration answered' and I think the sub heading is ' probleme met my 30000L dam' or something like that

Hi cam0

You always have seperate lines for all suction lines. If you connect the skimmer line to the bottom drain line, chances are that your bottom drain is not going to work and that the majority of water is going to be sucked from the skimmer.

1.If you suck directly from the skimmer and bottom drain you will have to have 2 lines leading to the pump with ball valves on each as to control the flow. Put the ball valves as close as you can to the pump as to make it easier for yourself down the road.

2.if you suck from a settlement chamber (where your bottom drain is suppose to be connected to) you can add a gravity fed skimmer into the settlement chamber as long as the settlement chamber is next to the pond. Then you suck only from the one line (settlement chamber)

3.My personal favourite is a mixture of both; take the bottom drain line to the settlment chamber. Then to take the settlement chamber suction line directly to the pump and to have the skimmer line also directly connected to the pump, with ball valves on each. That way you can control the suction.

Remember to check what size your suction line is of your pump and then increase the suction lines to the pump with one size. So if the pump has a suction size of 40mm use 50mm piping to the skimmer and settlement chamber.

Wayne

Thanks for the replies.

I am currently expanding my current pond from 3000 litres to roughly 9000 litres.

It is currently 3 X 1 X 1 and i'm going to change it to 3 X 2 X 1.5.

The pond currently does not have a bottom drain and it working through a 8000l/h submersible pump which goes through a 8watt uv light into a 25 litre ultrazap pressure filter (with some sponge thing for mechanical filtration and about half of it filled with plastic bioballs) and then back through a venturi in the pond.

Would you recommend I go external pump/sand filter for the 9000 litre or could I get away with installing a bottom drain to a settlement chamber where the submersible pump will sit pumping the water through the uv light and 25l pressure filter?

Thanks,
Cameron

Since you are going to make your pond wider and deeper; why not fitting a drain and skimmer at the same time. Will give you less hassles in the long run and the bottom should stay clean and leaves will the caught by skimmer before they sink. The 8000L/h flow rate will give a turn over rate of just over an hour which should be good on that size pond.
Only concern is that your UV will be too small for the bigger pond, and the flow rate to fast. Some people believe in Sand filters and I use a 2bag filter on my 4000L pond. Water is crystal clear but since I don’t have a proper pre-filter it clogs up very fast and has to backwash it twice a week and every 3months I have to take gravel out to clean. Must admit I have plenty small leaves falling into pond 24/7.
My larger pond is far less of a problem since I use 2 x drains, skimmer, 3 x 55W UV’s. Had plenty green water in beginning but it all cleared in a few days since the UV’s. Remember to replace the UV tube every 10 – 12 months. I also tapped the power going to my UV on/off switch from the output of my pump's switch. By doing it this way the UV's will switch off whenever I turn the pump off. Doing it this way will protect the tubes from burning out when no water flow is present.

Specs on Ultra Zap UV’s

8W Pond Capacity= 8000L with 2400L/h max flow
15W Pond Capacity=15000L with 3600L/h max flow
30W Pond Capacity=30000L with 8400L/h max flow
55W Pond Capacity=55000L with 18000L/h max flow

Hi,

The settlement chamber should act as mechanical filtration correct?

I was thinking of then changing the bio media into shells or some other form which has a larger surface area.

My problem currently lies with my pressure filter getting really dirty as it is acting as mechanical as well and I would prefer it to be completely biological.

I had the same problem with my small pond. Everything ended up in my sand filter but that is now I learned. I use Matala sheets in my large pond now and seem to be work well but expensive. Wayne uses Kaldness with a big surface area that seems to work very well with little effort to clean. You can visit the Happy Koi website. About R800 for 50L. It is always good to keep the big stuff away from your Bio filter with some sort of mechanical filtering. I have spent a lot of money on Matala but it seems to work fine till now. You get different density sheets that will act as mechanical filter and later on as Bio media and I have 4 x 1000L filter chambers in a 30000L pond but I had my reasons building a filter of that size and one is because my pond is located in an ugly part of the garden, so the filters acts as a barrier at the same time. Try to fit a proper mechanical filter before the bio stage. This can be sheets, shading cloth or any thing preferred. I had shading cloth in my chambers but I had a top-in and top-out filter system so most things bypassed the filter. Breeding nest for all sorts of badies and the nets stinks like hell. Modified my chambers to be an up flow system now. All sheets are under water with a gap of about 30cm at the bottom in each chamber. Water flow is equal in all chambers, and no channeling around any part of the sheets. Installed it about a month ago and no problems yet. Will see in the long run but I try my best to keep big bits in settlement chamber and clean it once a week. Hopefully the chambers will stay clean with little effort.
Submersible pumps tend to get clogged in a blink of an eye and a pain to clean. I prefer to use something that is above ground for easy maintenance

Hi CamO

This is propably the most complete and detailed website about pond construction. http://www.koicymru.co.uk/construct.htm I found that it explained everything.

If i can just give you some guidelines..

1. If you use a pressure sysem then your mechanical is after the pump and the bio filtration after the mechanical. A sand filter is only a mechanical filter.

2. If you use a gravity system your mechanical is before the pump and the bio logical is between the mechanical and the pump.

3. Depending on how powerfull your pump is you can have a mixture of both with mecanical infront of the pump, biological after the mechanical and before the pump, swimmong pool sand filter after the pump (acts as a polisher)

Thanks for your replies guys. Really appreciate it.

Ok so after a bit more research on that site you recommended and among other i've decided to try my luck at a DIY trickle filter.

The design will come from the following diagram I found on the web relating to DIY trickle filters:



Do you think this filter will be effective? How many litres should the trickle filtre container be to accomodate a 9000 litre pond? I was thinking of using my 25 litre ultrazap filter in series with the trickle filter as the pressure will be available from the pool pump.

I will be changing my setup to a gravity fed system using a skimmer and bottom drain. One question here: You say the pump must be after the mechanical and biological filtration, so does the skimmer bypass both filtrations and connect straight to the pump where the biological filter connects? i.e. 2 into 1.

Another question is where should the UV lie?

Here is a schematic of how I want to setup my system:



Any input will be appreciated.

You have to connect the drain / skimmer to your settlement chamber to ‘catch’ all the big stuff you want to get rid off. If you bypass it everything will end up in the pump and the liquidized stuff will be returned to the pond.

You say that you will be using a gravity fed system; does this mean that your new wet / dry filter will be below water level as well? If that is the case, you can connect the pump on the output of your system. Just remember to fit motor above water level. If you mount it below the water surface you will flood it when you open the leaf basket for cleaning, or when you have a leaking pipe. If only your drain / skimmer is gravity fed and new filter above ground level you need to place the pump before the filter to be able to draw water from drain / skimmer.

I will fit the UV’s after the filter. Mine is fitted between pre-filter and filter chambers. This is still a concern to me since it might clog up in time. This also prevents the UV to operate at it's best since some water will be ‘hiding’ behind the solid pieces and light will be unable to reach all areas. Just remember not to exceed the Maximum flow rate of the UV. If you are going to use the swimming pool pump the flow rate will be huge, so you need to split the pipes that only a small portion of water flows via the UV.

What sort of matting are you going to use in filter?

You will need about 25L of Bio Balls. They specify it to be enough for a 12000L pond, but keep in mind that the maximum flow rate for bio balls (25L) will only be between 6000 and 7500L per hour.

A 750 Watt swimming pool motor will have a flow rate in the region of 15000 – 20000 L per hour. This means that your turn around time of water in the pond will be around 2 times an hour which does not sound bad, but the material you plan to use, including the UV won’t handle the fast flow.

It is fun to build your own filter system but you might consider ready made filters designed for your size pond. They come complete with UV, Filter media and the correct pump size.

Hopefully this info will be handy but remember that I am no expert. I had a few problems of my own and made many silly mistakes that cost me a lot of wasted hours when I built my pond.

Thanks for the insight.

How can one decrease the flow rates through the filter systems and UV while using a swimming pool pump?

You just got me thinking now, wont the wet/dry filter flood if it is next to the settlement chamber if they both under the water line?

Maybe everything except the settlement chamber should be above the water level line so that they don't flood? But then I need to pump the water out of the settlement chamber somehow.

Now I am really puzzled.

Yes it can flood if filter clogs up, so it will be wise to have an overflow system back into your pond. Bear this in mind for each chamber. This will prevent you from draining the pond while you not at home. Also important is not to make the drain pipe in the chamber to short. Water in pond can not fall below the height of this pipe, so you can not drain pond by accident. The filter should not be below waterline, but rather at the same height. Your filter media must be places below waterline. Pack it tight to prevent channeling around it.

If you place the filter on the ground it will be easier to clean but then you need to fit the pump before the filter system. You can fit a low density filter matting in the drain / skimmer chamber to prevent big solid entering your pump. I see the recommended flow rate for the UV and Bio Balls are about the same. You can always fit a t-piece on the output of your pump (before going to filter) and redirect it via a pipe back into the pond. Fit a valve on the pipe going to the filter. This way you can control the water flow and you can close the valve whenever you clean the filter. All water will now be directed to the pond and you still have circulation while working

Here is a revised version of the design.

This should eliminate the fast water flow issue and ensure all water going through the filters is clean of debris?



There should be enough pressure after the sand filter to flow back to the pond and through the filtration systems hey?

CamO asked me to upload his new design and for people to comment