Building a HUGE Pond Filter - Part 4 - Moving Bed / Fluidized Media Chamber

Hello, welcome back to the fourth part of this mega filter build. Under here last time we concentrated on the brush chamber. There's a little bit more work to do to that, so I'll run through that at the start of this video but in this video we're going to be concentrating on the moving bed part, so I'm hoping to get the feed in done, the bottom drain done and the feed out done and when that work's done, I think we'll be ready to put the media in the moving bed part Or I might just wait until it's actually full of water and then add the media in. I don't know. At the very least, at the end of this video, I shall show you what I'll be using for the moving bed media. So let's get a start with this video by taking a step back and revisiting the brush chamber. Okay, I think it's time to seal this in properly now. This is the input into our brush chamber. I want to seal it in because I want to put this brush chamber to bed. I want it totally done. Don't want to come back to it So that is going to go in there and it's going to be kept in with our solvent cement. The very very smelly stuff. So basically all we're doing is just putting a decent amount on about two and a half inches of it, maybe six to seven centimetres. That's roughly how much goes into the fitting. I always like to put a little bit on the end as well just to make sure that when it slides up to that little stopper it absolutely sticks. So there we go, the whole lot is glistening, that means there's plenty of glue on. So now we just line that up, shove it in, give it a quick 90 degree turn, just to make sure that all the glue is distributed right around the joint, and then we just leave it. And if we try and move that now, after about 10 to 15 seconds, it will be absolutely stuck. I'm not going to try, because I don't want to upset the joint, but believe me, that will be stuck. That is a permanent joint. Now there is a slight gap around the outside of here, that won't matter because our pipe is pushed right through the side of here into our fitting. So there's no possible way the water can leak out of there. So our input here, which is through the rubber 90 degree bend, is going to be fitted on here We're here tomorrow. I did say this would be absolutely solid. It is. I don't want to take any chances though because this bend will be putting some force on it, pulling it this way. That needs to be absolutely one million percent set before that goes back on. Okay then, so on the last episode we were concentrating on this brush chamber. We've got the five outlets put in. Today we're gonna put the two inch pipe coming out, an elbow, And then a two inch pipe down into our moving bed chamber and in the moving bed chamber, which is that one, we need some sort of outlet to bring it through into the next chamber. We also need another bottom drain in there. Remember all these tanks will have bottom drains for easy cleaning. So the first thing I need to do is cut some suitable bits of two inch pipe. It'll be coming out from our brush chamber. to about here 90 degree bend and boom dropping water into the moving bed and i'm also going to increase the amount of oxygen that gets dragged in there as well so i've got five outlets i need five bits of pipe i'm gonna cut those with the chop saw fit them and then i'll get back to you okay there's our outlets on and if you're thinking they look a bit wonky Then you're exactly right, because they do. Because of the nature of this tank, the sides aren't perfectly straight. It kind of warps a little bit, you know? But what I'm going to do is attach a piece of wood from here along to that post, underneath these things to keep them up, and one across the top to keep them down. So in effect, as long as the piece of wood that goes underneath them and above them is level, it'll sandwich them in and keep them all perfectly level. And I'm not actually going to glue these ones in place. Although this is a solvent fitting, and actually you could just use push fit fittings if you want it to go all push fit. I like solvent because it tends to be slightly bigger diameter compared to the push fit ones. But you could just go push fit if you want. The reason I'm doing it this way without gluing it is because it gives me the option to tilt the outlet so I can alter. Where the water goes, so if I want these two pointing this way, in order to create a little bit of a vortex here, point the last two the other way, create one that way, and then have our middle one coming down here to create one going this way, it'll create a really chaotic motion. What I don't want is all of these just to be pointing straight down, and the water just to be cycling like that. All the way around, because the media isn't going to bump into each other. It's not going to create that hostile environment that really supports the active bacteria. Okay, so we're halfway through the inlets for the moving bed. But this is what we're going to have as the downcomer. So that's going to come straight down from our 90 degree. But we're going to supercharge it a little bit. We've got some pieces of aquatic hose here. I think it's 16mm, so that's about 5 eighths of an inch. I've cut an angle at one end and I've cut the other end off straight and I'll show you why I've done that. Now here's one I've got completed. Right, so near the bottom of this pipe our water is going to be moving exceptionally fast. So I've drilled a hole in here and a hole in here, stuck the pipe in and fastened it up here. So when the water is coming down here extremely fast it's going to drag extra air in through these two pipes, mix it with the water and put it into our moving bed. Hopefully you can see that that's looking down the pipe. You can see the angled bit is exposing quite a large contact surface area for our pipes so when the water hits that it's going to drag maximum air down the sides mixing it with the water spitting it out the bottom. And creating these is a pretty simple process. About three and a half inches up from the bottom we're just going to drill a hole which is bigger than the actual size of the pipe to allow for it going in on an angle. One there and one there. Feed our pipe in, strap it on up the top and that is our Venturi turbocharger unit ready to go. That just needs to stick through into there about an inch so that when we fasten that up there we're not restricting the flow the flow of water should still fly down there but just drag air with it that's it i really should have cable ties securing this but unfortunately i've ran out of cable ties and i can't find any more so the tape will have to do for the time being ideally that does want to be cable tied or as you guys in the US would be zip tied there you go so i've got two done i'll get another three done fit them and then we'll take a look and see what it looks like Okay, there's all our venturis in place and if you're wondering why I haven't taped it across the bottom here, you know why it kind of comes out, that's because I want to try and maintain the full diameter of the pipe as it goes into here. If I nip that in, it's going to cause a reduction in the diameter of the pipe which is going to reduce the amount of air that can get drawn in, so that's why it looks like it does. And hopefully, That extra air going in there will drive the moving bed very very well and that air won't be pumped in by an air pump it'll be dragged in through here and dragged in through our little turbo units. Okay that's our bottom drain in just ready to permanently fix just take that off for time being and we'll concentrate on the inside of there now. Now there's our bottom drain right near the bottom there and because we're going to have small moving bed media in here We can't just have a bare two inch bottom drain. We have to fit some sort of straining mechanism. Okay so what I'm going to do to prevent the problem of all of that moving bed media just disappearing down the drain pipe when I open the bottom drain is that that is going to be our bottom drain inside the moving bed module. And if you're wondering how in the hell the water is going to actually get out of there, well I haven't cut the slits in it yet. If you haven't got a chop saw, or any sort of useful saw, just to go down and put loads of slits in all the way around here to let the water into the middle of the pipe, just drill loads of holes. As long as the holes that you drill are smaller than the size of whatever the moving bed media you're using is, it will not go down here and it won't disappear down your drain. So I'll get all these straight bits cut with a load of slits, because they're not glued in. And in fact these bits will never be glued in. There's no need for these bits to be permanently glued, there's going to be no pressure, no water wants to be held in here really, so they can just go in loose. That'll just slot into the back end of our bottom drain and all the water will go through all the slits down the drain when we open the tap. One thing I am going to do before I actually pull this thing apart is just mark where the joints are, the permanent marker. Because I don't want to be cutting slits where I don't need to. I could just eye it up, I suppose it goes in there about an inch and a half. But at least I've got a line to work from. I know that anything between these two lines is fair game to cut slits into. Okay then, that is our drain pipe. You can see the slits cut all over it to make it extremely accessible for the water, but not accessible for our moving bed media. And in this particular section, there's not going to be any bigger muck than that. Because we've got the vortex units and we've got the brushes before it gets to here. So cutting holes in that size is fine. So that's it laid out there in the bottom. It's roughly in the middle of the container as well. Didn't actually measure anything, it just worked out that way. Worked out pretty well. So now we'll need outlets here and possibly here, which will also not let any moving bed media out. Okay, so as far as the outlet from the moving bed into our static bed chamber goes, we're going to be using these again. These are our four inch connectors and we're going to be going with the longer screws again as well because these containers are actually thicker than I thought they were. They're really thick. These little screws that come with these fittings. aren't long enough so just like we did with the brush chamber we're going to go with the 40 mil screws they get a really good hold they pull the two bits together and the sealant really sticks it now we're going to have two outlets on this particular chamber and the reason i'm going for two is because i want a piece of four inch pipe to go out bend around and then come back to the other outlet so we've got a really big catchment area for the water and instead of using solid pipe I'm going to be using that which is a really hard rigid perforated pipe that goes in there. We'll stick a solvent bend on there, another piece of perforated pipe, another bend, another piece of perforated pipe back to the other outlet. So we'll have a lot of good water movement through all of this stuff. The moving bed media won't stick to this at all, it'll just move all the way around it and it'll ensure that the water flows out nice and slow but with a good volume to our next chamber. and then in the next chamber we'll have an elbow and we'll point the water down so it comes out the top of this one and down so the water travels as far as it possibly can in each part of our filter that ensures a good dwell time whether it's on moving bed media static media or whether it's in that end container where i'm going to have showers i'm also going to have static media in there the water wants to spend as much time as possible In this filter, there's no point building this huge thing and then just whipping the water through it because it's not going to have time to get acted upon. And this moving bed chamber that we're doing is going to be a really, really highly oxygenated zone. But the water that comes out of it... doesn't really want to be too oxygenated because it's going to go into the static media so we want a mix of aerobic and anaerobic bacteria in the static media so we're constantly speeding the flow up slowing it down directing it to places so it spends a long time in gets deoxygenated then gets re-oxygenated somehow it's quite a complex process but i'm trying to give the information out to you to make it as easy as possible to implement And also to replicate as well, because remember I said in the last video that there's no point me spending tens of thousands of pounds and putting the world's best filter in here if it can't be replicated by anybody watching the video. I really hope that all of these processes that I'm doing in this series of videos can be replicated, so they should be useful. Okay, let's get this roughly cut to size. I think I'll more or less glue it in position. And then I think it might be time to whip some of these containers out to give me access to drill the holes to fit these. Okay, it got a little bit too dark, so I couldn't really film or finish off the moving bed part of the filter. But I'm back, and that is what I've made for the outlet. Remember I was explaining that that was going to go on the side of the tank. This goes on the inside. So we've got a good area to draw water through to move into our next chamber. Now I did use the solvent glue on here and it didn't stick very well so as well as the glue I also used the aquatic silicon and I've actually siliconed all these joints in. As you can see it's absolutely solid. So now all that remains is to fit this on the inside of our moving bed chamber. But that's going to involve dragging these containers out to give me a little bit more space to work. That will hopefully let a little bit more light in. And then as we're working from the back forward, hopefully the successive videos will get lighter. Because I don't have a light under here and I've been working pretty much in darkness for the last few videos. Okay, so this is the outside of our moving bed chamber. I don't really want to be working in there because it doesn't matter which side I drill the holes from. So basically I'm looking to drill a four inch hole the size of that off cut in here and in here to match up with that and that. Okay I've just roughly marked that then I can put the fitting that I'm going to be using on there using the pen line as a guide is the bit that I need to cut out and it should match up with that which it does perfectly. Now, I just eyed this up. It doesn't need to be perfectly level, and that's because, ultimately, the level that this settles to will be dictated by the outlet in, not the next tank, but the next tank after that. As long as I get that right, the water will be up here. Moving bed media will be flowing all the way around the outlet very, very well, and everything will be okay. So, I know the base is level. The tank, therefore, is level. The mark is roughly an inch below here. And about an inch below here, so it's going to be pretty much level. Mark that one, and now I need to cut it out. And if you remember from one of the previous videos, I don't have a 4 inch hole saw, which would do a beautiful job. So I'm just going to use a hand drill, with a drill bit about that size in. I don't know, what's that, 3 eighths of an inch? A quarter of an inch, I don't know. Basically, I'm going to drill through and then use this to cut the hole out. It is not going to be perfect, but it doesn't have to be. That's one side done. I'll do the other side and then we'll put our fittings on here. Okay, so now to fit our outlet on the inside of this tank, I've taken the back plate off here. I'm going to put a bit of pipe in here and slot that through the hole. Therefore, I know that that is in the right position. I'm going to put the screws back in here to mark the inside and then I'm going to drill little holes where the screws go and that'll allow me to fix this plate on the outside and get the screw holes in the right place. As long as I've got little holes to let me know where to drill the screws through, I can position this, put the screws through and it should marry up with these to secure it. Remember we're not looking to actually fix this thing permanently this way we're just marking it so we know where to drill the holes and then we take them out and that'll leave little marks on the inside of here we'll drill holes through and then we can get our plate on the outside with the screws in the right place. I can't see where I've marked it on the inside of here around the bottom but we have got one two three four holes drilled Really, a couple of holes would be any amount to enable us to get the outer plate on properly, so that's not bad. As long as we've got a few drilled, we can make it work. Okay, that's going to work out good. If you remember from the video previous to this, where we were doing the brush chamber, we had a 4-inch inlet going into there, and we used exactly the same fitting there. We had to step up the size of the screws, so I've thrown away the screws that came with these fittings. I'm actually using ones which are sherardized, which means that they're not going to rust, and they are 5 by 40, so they're 40mm long and 5mm wide. It doesn't really need to be that long, but I like the thickness of them because it really gets a good hold, you know, in those fittings. They may stick through the fitting a little bit. Stick out the back, but they're not going to be anywhere where I'm going to be in and catching them on my arms. So I don't care about that. If you put these fittings anywhere else and they are sticking through and you are worried about catching yourself on them because they are damn sharp, just get a grinder and grind the ends off. Okay, so that's going to work well. Now all we need to do is put some silicone on the inner flange inside of here. Put this plate back on, screw them together, PFFFT! Silicone, stick everything up, waterproof it on the inside and that will just about be this module done. Okay, no need to be neat, just slap it on all over the place. As long as it creates a waterproof gasket, it's all good. Now I'm actually pressing this flange on the inside against the wall of this tank, so that when I screw that in, I know that the screw's pulling everything together. Right, we'll just bring the camera in, I'll let you see what it's like on the inside. Now I haven't done anything to neaten this up, as you can tell it's still very wet, but that has created a hell of a gasket around there. And you see what I'm saying about the screws? They're sticking through quite a lot, it's not going to be anywhere where I'm going to catch it, but that can be taken off with a grinder. Now I've just whipped the pipes out that I used as a guide to get me through the hole to line it up properly and you can see that as I've screwed these screws in and drawn everything together the silicon has actually come through and it's totally sealed it up front and back basically it only needs to be sealed from one way because we've got a piece of solid pipe going through here our fitting goes through the tank so there's no possible way the water can get out of That is, unless it comes out of a little pipe and goes through into our next container. Okay, so that's our moving bed chamber pretty much finished, apart from the actual media that's going to go in it. We've got our drain in the bottom there, which is all perforated, so we don't lose any moving bed media when we drain it out. We've got our outlet, which again is a perforated pipe. solidly fixed in through the sides there and that is going to ensure that we get water through here in huge volumes without any media escaping into anywhere else. We've got the inlets coming in. Oh actually I was saying this is just about finished. It isn't finished. I still need to put the wood underneath these pipes and above the pipes to sandwich it in and level them all up so they're all nice and level. But apart from that little bit of wood this module is finished. Right I'm going to get these two containers pushed back because it's looking like it's going to rain and then we'll talk about moving bed media. Right I'm going to show you three different types of moving bed media but before I do that I'll just explain the benefits of a moving bed. Basically it involves using plastic media that is either air driven or water driven. Most of the time well 99.9% of the time it's air driven so you'd have a container with an inlet and an outlet An air source in the bottom, which might be a perforated pipe, it might be an air stone, it might be an air plate. Basically something to produce a lot of air that rises upwards through the media, through the water, causing it to have really chaotic motion, all the bits banging together. What that does, it creates a very hostile environment for bacteria. Bacteria doesn't really like to grow on plastic anyway. You know, as a static media, plastic is pretty much useless. But, as a moving bed, plastic media can be very, very good. Because of that hostile environment, only the fittest, strongest bacteria can actually colonise it. And although it can take six months to properly colonise with aerobic bacteria in that environment, once you keep that filter running, so there's water going through it all the time, and there's ammonia and nitrite for the bacteria to consume, it'll do an incredible job of that side of the cycle. Now I'll just quickly mention what a cycle is because a lot of people still don't understand what a full cycle is. Most people will look online, they'll look at the nitrogen cycle for a pond or for an aquarium and they'll see that bacteria converts ammonia to nitrite, nitrite to nitrate, nitrates build up in the water, they get taken up by plants or they get reduced by water changes. That is only half the cycle. There is another side to the cycle, which is anaerobic bacteria. In a moving bed it isn't possible to grow anaerobic bacteria because it's such an aerated environment. Plastic's not the best media to colonize anything with so it's only aerobic bacteria that colonizes it. So this moving bed filter that we're putting in is to strip out the ammonia and the nitrite from the water. The end product of that will be nitrate and that is what What we're going to try and work on in the next few containers. because they'll be filled with a static different sort of media which i'll cover in a future video so now hopefully you understand the benefits and also the drawbacks of using a moving bed filter they're good as part of a filter system but if you expect a moving bed to do the whole cycle then you're going to be sorely disappointed and a lot of the videos on YouTube that have moving bed filters in sumps or in little aquarium diy moving beds they tend not to explain the the pros and cons of the media so hopefully that has given you a little bit of information all right so the first media is the one That anybody who's looked into moving beds will be familiar with, K1 moving bed media. That has been out for many years. It was initially developed for sewage and water treatment plants in Denmark, if I remember rightly. And they produced it in a range of sizes and different shapes and so on. Now eventually, the co-keepers in the UK worked out that you could use a moving bed filter in a koi pond to reduce the ammonia and nitrite and really keep the water healthy as far as those two pollutants go. Now unfortunately that really great discovery didn't progress beyond that until very very recently so even now you get filter systems that cost thousands. And basically there is the mechanical filter followed by a biological filter, and that biological filter is a moving bed. So you might not have any ammonia or nitrite, but you have sky-high nitrates, which affects the fish's growth, it affects the digestion, it affects the oxygen content in the blood, it affects the nervous system. So you've got to do water change, water change, water change, water change to bring that nitrate down. Now that's frustrating because I've met loads of manufacturers and I've tried to explain that the nitrate needs to be worked on as well and they're just not interested. Basically their filters, which can cost thousands, don't do a better job than a DIY sort of moving bed filter in a 45 gallon room. That's the harsh truth of it. So you get these guys with really fancy filters And the water is no better than the guys who've just knocked something together in the back garden. It's a really funny situation that only that first half of the cycle is concentrated on. Anyway, I'm rambling now. Sorry about that. That's the K1. A few years ago, K1 Micro was developed. And that is a lot smaller. There you go. K1. K1 Micro. It's much smaller. And that was actually developed in response to the mad craze that went through YouTube of people making DIY moving bed filters in their aquariums. And if you want to know who started that, you're looking at them. Although my videos aren't the most popular, some channels that basically stole the idea and put it out as their own have got millions of views on their moving bed videos. Again, that just makes me laugh. The idea is out there. It would have been nice if they'd given me credit for it. People tend not to do that nowadays, so that's two types of moving bed media, both from the same manufacturer, one of which, the K1, is commonly used in moving bed filters in koi ponds. A lot of people, including the manufacturers of these big moving bed filters, don't consider using the K1 micro in it, but you can get a hell of a lot more media in there. And as far as surface area per litre goes, the K1 Micro has got about 40% more surface area per litre. But there's another sort of media from a different manufacturer that also has about 40% more surface area than standard K1. This one is called Helix 13, and this one's from Oase. There you go. As you can see, that one is a lot more intricate. So that does build up a lot of muck on the inside of there, on the protected surface area. And as I mentioned, this one also has approximately 40% more surface area than standard K1 per litre. So what I'm going to ask the guys who own these Nexus filters is, why in the hell are you using K1 when you could boost the biological activity in your filter by 40% purely by changing the media? That makes perfect sense to me. Change the media, boost the filter, increase the filtering capacity of your filter. It's something to think about. But I'm not going to use any of them, not because they're no good, but because my filter is going to be driven by aerated water falling down into the media. If I use small media like that, as the water's coming down, it'll probably just have a very localised effect. So I'm going to go with something bigger, from the same people who make the Helix 13 in Denmark. And I've actually bought two 200 litre sacks of this stuff. It's basically a bigger version of the Helix 13, that's it there. As far as I can remember, it's called Helix 17, and the 13 and 17 relate to how long it is. So this one's 17mm, the Helix 13 is 13mm. It'll basically do exactly the same job, but because it's bigger... I'm hoping that the water will hit it harder move it further and therefore give me a better turnover. So that's what I'm going to be using in my moving bed and if you want to use something similar to that I'll put the link to it in the video description if it's still available. And that stuff is what's used in a lot of the treatment plants in northern Europe so that's why I'm using it in here it's more like an industrial thing for really big moving beds you know. Not quite sure how much will fit in there, but I would imagine 400 litres will make quite a nice soup of media. By the time the water comes out of this huge filter system with all these various parts, I want the water that goes back to the pond to have no ammonia, no nitrite and no nitrate. That's quite a big ask of this filter because I'm going to be pumping a lot of water through it. There's a lot of fish in my pond. I feed them quite heavily. So, I'm going to need it to be working very, very efficiently to ensure that the water that goes back to the pond is good. And if I can get good water quality in my stupid-sized pond, surely you guys could do a scaled-down version of various parts of this and also get really good quality water in your pond. Hopefully, cheaply, because the last thing you want to do is waste. Thousands of pounds on filters, like I've just mentioned before, when you could do it in a DIY way and get better results. Right, so I am rambling quite badly. I should really plan what I'm going to say, but hopefully you've found something I've said there useful. If you have, give it a thumbs up, share this video wherever you want. And in the next episode, we're going to be concentrating on these two containers, which will be a static bed filled with a hell of a lot of media. Thanks for watching. See you next time.