Ed's filter's K1 conversion

[eds]

Thanks for all your advice and after all your help I hope these pictures and writing may help anyone converting their blockwork filter to K1. You can see more stuff on it's old configuration on [url=http://mauricecox.proboards54.com/index.cgi ... hread=1078]this thread[/url].

This is the brush chamber before it's conversion to Static K1.
[img]http://i128.photobucket.com/albums/p169/eds ... 0_2088.jpg[/img]
Rather than block the 1.5" drain I'm going to add a vertical partition with 10cm by 4mm slots at the base.

To make it easy to alter and modify in the future I'm not securing the dividers in but fixing channels to the walls that the 5mm Black Acrylic simply slots into. The channels are 10mm end capping for polycarbonate panels and the large flange at the end allows me to easily secure them to the concrete walls via screws and plugs, all sealed with Gold Label.

Here are the two deep channels secured in,
[img]http://i128.photobucket.com/albums/p169/eds ... 0_2089.jpg[/img]

And a view from above showing one of the channels,
[img]http://i128.photobucket.com/albums/p169/eds ... 0_2090.jpg[/img]

After they were secure the 5mm Acrylic was cut to size and tested that the base was a close enough fit to the floor of the chamber so no K1 could slip through! All good so far so I cut 4mm slots with a circular saw 10cm long at 2cm intervals. This gives me 25 slots with a total area of 1000mm2, larger than the 4" pipe feeding the filter.

Here's the sheet in place with it's white protective film still on; it looks far smarter in glossy black...
[img]http://i128.photobucket.com/albums/p169/eds ... 0_2092.jpg[/img]

Next I sorted the air pipe from 15mm Speedfit pipe. I have branched the pipe to feed both the fluidised area and the static and used ball valves to control them. With the pipe clips fitted this is all held securely so far without needing any clips below the water level.
[img]http://i128.photobucket.com/albums/p169/eds ... 0_2093.jpg[/img]

The one big problem I had was with the divider to seperate the static and fluidised sections. This is currently a concrete wall with a 7cm height of water above it. This meant I can't use slots 2cm apart as I wouldn't have enough gaps so I tried to use slots 1cm apart. Unfortunately these were too delicate when sawing and simply snapped off. So I ended up going with 8mm drilled holes. I've done 5 rows of them packed as close together as I dare.

Here it is drying as I has to use two sections and glue them together as I hadn't bought enough acrylic to do another single piece.
[img]http://i128.photobucket.com/albums/p169/eds ... 0_2094.jpg[/img]

However all these holes were still not enough once the K1 was in and blocking half. At the minute I've simply cable tied a filter brush to keep the K1 from blocking the holes and this is working well.
[img]http://i128.photobucket.com/albums/p169/eds ... 0_2095.jpg[/img]

I'm now thinking how best to fix this permanently. I'm thinking of adding a slotted sheet at an angle lower down or a kind of box arrangement to up the surface area, but haven't decided yet. I'm also kind of hoping that once the next chamber is fluidised the current from 60l of air may actually puch the static K1 away from the divider slightly, but I doubt I can be that lucky!!!

I'll be finishing it once I feel a bit better!

[kayoss]

Hi Ed

Have you tried putting a sheet of matting on top of the static K1 to hold it down?
That's what I've done on my DIY eazy and it works well - just lift the sheet off before you aerate the K1 to clean it, rinse it off before you put it back (using a hose is OK as it's not providing biological filtration) and all your pond water will flow up through the full depth of the static K1 layer to give maximum mechanical filtration!

Cheers

[Gazza]

Hi Ed,

Once you start the modifying game thats it your be out there tweaking it hear and there

Looking good mate and you will defiantly see the difference not just in the water but in how easy it is to clean which normally means its a job you wont mind doing so will keep on top of it

Is it possible to remove the small wall or even gut a section out in the middle just leaving some end bits so you could then install a full hight filter grid in and drill as many holes as you would like.I know its more work but it could solve the problem and give you a better flow

[Davej]

Hi Ed

Am I right that at the moment if the static K1 clogs the exit holes the water level will rise and you will get K1 everywhere?

Dave

[eds]

Hi Ed

Am I right that at the moment if the static K1 clogs the exit holes the water level will rise and you will get K1 everywhere?

Dave

The two vertical pieces of acrylic continue way above the very highest point the water and K1 can get to. So the K1 is pretty securely kept in this section. There's about a 3" clearance above the normal water height.

Gazza I know what you mean, I'll be tinkering until it's right. I did think about getting the angle grinder out and taking 4" off that wall but was hoping I could get away without it.

Bob, I don't want to cap off the K1 as it means I'll have to get my hands wet when cleaning it!!! Seriously the idea is that this filter is as easy to maintain as possible so I'm not the only one that can clean it! I also think the matting itself will clog and then need extra cleaning.

I think a box section where the brush is now might be an answer. I was thinking about getting some square section downpipes and cutting/drilling that then glueing it to the current divider. That will allow a larger areas to strain the K1 and might solve the problem.

[Davej]

Hi Ed

Agree greater surface area of the K1 area is the key. Must say that I would be putting some form of lid on the K1 chamber of drilled plate, on the basis that an overflow of some kind is always useful and experience is that if it can happen, it will, and we all like to go on holiday at some stage relaxed that things are fail safe!!

Regards

Dave

[eds]

Hi Ed

Agree greater surface area of the K1 area is the key. Must say that I would be putting some form of lid on the K1 chamber of drilled plate, on the basis that an overflow of some kind is always useful and experience is that if it can happen, it will, and we all like to go on holiday at some stage relaxed that things are fail safe!!

Regards

Dave

I understand what you're saying about playing safe and when leaving things unattended, but it's a gravity fed filter and for the water and K1 to get that high the water would have oveflowed the main pond by about an inch! The filter walls are an inch higher than the pond walls! K1 can't climb out of the water can it?!!!

[Jon W]

Hi Ed

It can actually! When static K1 starts to become clogged with debris I've noticed that it starts to clump and lift up above the water level. It's never done it to the extent that it has exited the filter sides because the sides of the filter extend another 4 inches above the waterline.

Cheers

Jon W

[Davej]

Hi Ed

Glad to hear there will not be an overflow problem!!

How are you going to block off the static K1 chamber when boiling it to avoid contaminating the Bio stage? Slot in plate or can you drop the level down below the exit slot level?

Regards

Dave

[eds]

Hi Ed

Glad to hear there will not be an overflow problem!!

How are you going to block off the static K1 chamber when boiling it to avoid contaminating the Bio stage? Slot in plate or can you drop the level down below the exit slot level?

Regards

Dave

All I do to block off the static section is to drop the water slightly and then the two sections are separate. This section is working well now with the brush in place and while I want a permanent solution it'll do for now. Turning on the air for 5 minutes is certainly easier than cleaning brushes!

[Davej]

Hi Ed,

Excellent, I couldn't tell from the photo if you had room to drop the level sufficiently ..

How much K1 have you in there and is it trapping much?

Regards

Dave

[eds]

I set to doing the fluidised section of the filter today.

First I removed the original flocor media and media grids. I was amazed how much detritus there was in the corners, under and around the grid and in some of the flocor media. If you still have this don't assume and good swirl around every time you clean the filter will keep it clean as I did this to mine every week and have a sloped base to the chamber and it was still shocking.

Once the media was removed and the chamber cleaned I set to work. First I was going to cut slots in some 2" pipe and use that to cover the pump intakes, but then I found a large water lily basket that had lots of small holes just the right size to keep K1 out, so I used that! I've secured it by cable tying it to the current strainers.
[img]http://i128.photobucket.com/albums/p169/eds ... 0_2096.jpg[/img]

To block the drainage holes I used 20cm lengths of 1.5" pipe slotted into the 1,5" bends in the concrete base and fitted red caps to them to block the top. I've cut 4mm slots into these pipes.

Then I had my first error. I decided to drill 2mm holes 3cm apart along the 1.8m of speedfit pipe that would go along the bottom but on trying it the air all came out near the end and not all along evenly! After a few choice expletives I removed that and drilled 1.5mm holes 5cm apart. Refit the new pipe and zip tie it to the drainage pipes.
[img]http://i128.photobucket.com/albums/p169/eds ... 0_2097.jpg[/img]

The result, a nice even boiling in the chamber.
[img]http://i128.photobucket.com/albums/p169/eds ... 0_2098.jpg[/img]

However once I added the K1 I noticed a major issue. As the flow goes from right to left on the above picture so does all the K1. It all clumps around the strainer to the pumps and is a solid mass that the air bubbles can't move and fluidise. I'm not really sure how to solve this. It's a long narrow chamber and the flow along it is obviously pretty quick with about 2,500gph flowing through it.

I reckon there are a few options:
1. Re-arrange the air pipe so it's a number of pipes running across the chamber rather than along it to get the K1 to flow around against the flow. Not sure this will solve the problem though.
2. Put series of dividers in to keep the K1 in several sections, each of which will boil around hopefully more successfully. If I do this I'll probably leave the section near the pump intakes clear of K1 as the build up of some static K1 there then spreads down the chamber as more media gets stuck together.
3. Spread out the pump intakes further up the chamber using 2" elbows and strainer fitted to the ends. This would then spread out where the water's being removed and reduce the flow down the chamber.

Any advice would be appreciated guys.

[eds]

Hi Ed,

Excellent, I couldn't tell from the photo if you had room to drop the level sufficiently ..

How much K1 have you in there and is it trapping much?

Regards

Dave

Cheers Dave,

I've cleaned it three times today now I've set up the air pump!!! It's trapping lots of debris and there's only about 20l in there. I added just enough to cover the exit holes as I figured why add more?! It's certainly better than brushes, trppaing lots more and so much easier to clean.

[Davej]

Hi Ed,

Good to see the progress.

Have to tried concentrating the air in the fluidised section at the outlet end? Try throwing in a big airstone there to help push the K1 against the current.

Otherwise would think it is down to increasing the surface area of the strainer to minimise suction, can you get a 4" elbow in there with a drilled/slotted section of 4" pipe?

Regards

Dave

[Gazza]

Hi Ed,

Yes its surprising what you can find when removing old media from filters

One of the problems with long chambers is if you are drawing from one end you can get a build up of K1 at that end,i wonder if you did set up some smaller chambers withing it sectioned off if this would work better with smaller air rings in them.

What size air pump are you using and how much K1