After answering some questions through PM, I'm continuing the topic here, so others can benefit as well!
Thank you for your reply !
What do you think about this design : ( https://www.koivrienden.com/phpBB/viewt ... 40#p286840
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The subject is in Dutch, I can only understand something from the picture...I think the dimension is similar to mine, but I will have two bottom drains.
For which those valves in the first chamber (the middle valves on the T-pieces) ? How such type of filter is cleaned ?
The sewer pipe on me is higher than the bottom of the my filter.
What is the recommendation for the filter material in this topic on koivrienden ?
This guy has some very nice drawings indeed. I think it is well thought out for the most part. The members there have some comments on the design, I will tell you more about that in a second. He also has this very specialised idea for a plant filter that can be moved, but I don't think you want to use that idea? The guys on the forum are saying it's a bad idea anyway.
Other than the plant filter it's a very solid concept drawing.
His idea is to use one bottom drain, one side drain and one skimmer. He says the filter will be 4 chambers, the first chamber has the Crielsieve as you can see, the other 3 chambers would be filled with Japanese matting.
The other members advise him to add another bottom drain, and to make the pond bigger.
He wanted to use 75mm pipe on his skimmer line to limit the flow through the skimmer, but they advise against this and say to use 110mm.
Another thing they say, is to remove the dividing walls he uses all over the filter. The one next to the Crielsieve is not going to help, and the other dividing walls in the rest of the chambers will just limit flow.
Also, 3 chambers full of Japanese matting will limit flow too much as well.
According to them it's better to start with the Crielsieve chamber, make the second chamber a static bed filter to filter out even finer particles (optional), third chamber should be a moving bed filter and the last chamber could then be filled with Japanese matting.
I agree with this by the way, this is very similar to what I'm going to use myself.
You asked about the middle valves on the T-pieces in the first chamber. To be honest I was not sure about these myself. I think these are used to clean the bottom drains and pipes. This way you can keep the filters undisturbed, and keep the normal water level in the filter (by adding a bit of pipe at the top of the inlets in the first chamber). I am not 100% sure, but I think this is the reason. personally I would not bother to build this as I think you can just clean the bottom drains by closing them at the first chamber, emptying the first chamber, and then letting it fill back up when you open the bottom drains again.
So I think this is just a very neat way of doing it without having to empty the first filter chamber. But considering the cost of these valves, I would not use this.
An important tip from me though: If you look at that drawing you can see that each filter chamber has its own drain with a pipe going all the way to the start of the filter, where they each have their own gate valve.
Doing it like this is a bad idea. As you can see these valves are the only thing that close off the filter drains. If they start leaking, they immediately leak into the filter pit, and the pond will lose water.
At this point in the filter, the best way to do this would be to use another ball valve after these four gate valves.
Gate valves are much cheaper to buy than ball valves. But the problem is that they WILL leak after some time. When you're just closing between the pond and the filter, this is no problem as the leak is always small. But in this scenario it will slowly empty the pond if you're unlucky. Adding another ball valve after these gate valves is a good way to ensure that it won't leak.
What I mean by that is, you should connect these four drains to one pipe, and place the ball valve on that pipe.
About your sewer pipe:
If your sewer is higher than the bottom of your filter, then you should not connect to it, you won't be able to empty the filter in that case.
I'm thinking about this as well. Normally you would have a filter pit (like the one in the topic) where you can empty your filter. In this pit you place a pump that can handle the dirty filter water and pump it out. Connecting directly to your sewer is ideal but not always possible.
Wow !! You helped me a lot with this answer and now is much more clear to me !!
In my case i have this kind of wall skimmer (http://www.koi-spirit.de/teichbaumateri ... m/a-10337/
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About dividing walls you suggest that i only build one concrete dividing walls between chambers ?
Static bed filter is chamber fill with for example helix without moving air - Is that correct ?
Can i use this for connect each chamber to the drain pipe - http://www.koi-spirit.de/pvc-fittinge-z ... m/a-10109/
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And last question is can i use normal 110 mm sewer pipe for all connecting in pond and filter or i must use some kind of special pipes and can i glue all PVC pipe and fitings with ragular Henkel Tangit glue?
Of course, You can switch this conversation into the topic, I hope this might be of help to other beginners.
You could maybe modify that skimmer in a similar way as Gino did.
You can see that here at the end of the first post (part one):
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He had a skimmer with a 160mm opening (outside diameter) which had to become 110mm (inside).
In your case, the opening is much too small. But looking at it it seems like the skimmer could also be 160mm (outside diameter) before it has the small outlet.
If it is 160mm, maybe you could just use a saw and take the end off. After that do the same thing that Gino did in the topic above and you will have a 110mm skimmer.
I think it is common to have to alter these skimmers, depending on which ones you order.
I would not use the extra dividing walls that you see in those drawings. I have an idea for the filter bays, which I will also use. Marc gave me this idea, I will make a drawing of it later as it's a very nice design.
Yes, a static bed is pretty much just like a moving bed filter but without the Air supply to rotate and aerate the media. The difference in function is that a static bed will also function as a fine filter.
I don't think it's necessary when using a Crielsieve, as the particles that can move through are really tiny. It's more of an extra measure, depending on how clear you want your water to be as well of course.
If you build your chambers out of concrete blocks, you normally build the drain into the floor or wall of the chamber. The part you're showing is a transit used on liners or plastic containers. If you build your chambers out of concrete you will not need these. I'm no expert on concrete filter bays though. So if you want to know what the best way to build the drains is, I will have to check with Marc.
You can connect your drains all to one pipe with a ball valve at the end. This doesn't have to be 110mm. I think this will be overkill and ball valves become much more expensive as you go bigger. I think 75mm should be more than enough. I have 50mm drains on my current filter and those are 250L barrels I think.
Personally I would still give each chamber a gate valve so you can drain them individually.
The type of PVC used is a heavily debated topic. If you want to be absolutely safe, use pressure PVC pipe from the bottom drain until your filter connection. Since this piping is under your pond with the most weight above it. Also, if that piping breaks, cracks and leaks, you will not be able to easily get to it and repair it.
For everything else I would personally just use normal PVC. Be very careful and make sure all your pipes fit the socks, bends and valves you will use.
Any glue made to glue PVC should be fine (any of the known brands for sure).