Blitzkragz' 12ft 375g rimless peninsula with rotary drum filter build

[MaddyP]

Following! Love the idea of a self-cleaning roller mat...

 

[dantimdad]

I think it's a great concept, but, $3500 for a prefilter? I will do maintenance.

 

[blitzkragz]

I think it's a great concept, but, $3500 for a prefilter? I will do maintenance.

For sure, they're not cheap. It depends on the person on their tradeoff threshold between personal maintenance time requirements and cost.

The model I got is the smallest one made, and rated for a whopping 6000gph. I am sure if a manufacturer were to make one half the size for your typical max gph of a synergy overflow of 2500gph, it could come down to half the price. Maybe they will take notice of this build and wisen up to a potential new market. But let's be the first to try this out and see if it actually works for a reef tank!

 

[Mortie31]

So let's talk about RDF's.

RDF's started becoming popular around 10 years ago in the koi hobby. They are about as close to zero maintenance mechanical filtration as you can get, and can handle massive amounts of flow (although you can have much lower flow than their ratings). Water flows into a screen-wrapped drum, and when the water level rises because of detritus, a float switch kicks in, the drum is rotated, and a spraybar cleans the drum by spraying the waste on the screen to a waste drain.

There are a few hurdles I think have prevented anyone from trying this in a saltwater aquarium:

1.) their large size
2.) noise
3.) need to be plumbed to a waste drain
4.) their high cost
5.) possible effects on salinity
6.) metal parts

But I am adamant on making a concerted effort into working around the above if it means no long term maintenance with filter socks. Since this is a fish room install, problems 1, 2, and 3 aren't an issue. I am fine with 4. 5 is a "let's see what happens". 6 will take some custom work.

Currently there are two main RDF brands you can buy in the US. There is Profidrum and Red Label. I contacted Profidrum and got confirmation that their filters can and have been used in saltwater with a "salt seal kit". The problem I have with Profidrum is they are mostly made of 316 stainless steel (the drum, the screen, the tray, etc are all steel). There would be a lot of steel being completely submerged in salt water, and my understanding is that even 316 stainless will corrode over time if submerged.

Then there is Red Label. Red Label RDF's are mainly made of Polypropylene, with relatively few metal parts, and their filter screen is nylon. A couple issues with their smallest model is that the high pressure pump sits in the filter itself (meant for koi ponds, it uses the filtered pond water for the spraybar). Another is the few metal parts in it are not 316 stainless.

I decided to go with Red Label, and take on the project of adapting it for saltwater use, which I think in the long run will be better than having a mostly steel filter. It shipped out today from seasideaquatics.com. My plan is to disassemble it when it arrives, and send the metal parts to a machine shop and have them duplicated in titanium. Some things like standard screws I might be able to get titanium versions on Amazon. It should be pretty straightforward to modify it so that the spraypump sits in an external tub filled with RO, and then something like a Tunze Osmolator to fill it up after a spray cycle.

Here are some pictures of the filter I have coming:

Here is a video of one, kicking off its cleaning cycle at the end:

You should go the whole hog and get a Koi pond bubble bead filter as well, as for the roller filter these work great in the Koi world, salt spray could be an potential issue, hope you have a good lid..

 

[blitzkragz]

You should go the whole hog and get a Koi pond bubble bead filter as well, as for the roller filter these work great in the Koi world, salt spray could be an potential issue, hope you have a good lid..

Bead filters are a bit less popular than they used to be. They require maintenance to flush them, and a lot of extra energy for the head pressure to force water through them. An RDF will filter 70 microns with massive flow with no maintenance and can be gravity fed. A bead filter will however filter super fine particles. But as long as I am getting the same or better than filter socks, I'm happy!

The actual spray part will be reverse osmosis water, not salt water. Almost all of the sprayed water passes through the screen and out to waste.

There will be some overspray, which is where we will test to see how it affects salinity. As long as the amount of overspray during the day is always less than the evaporation on the tank for that day, there will be no affect on salinity. In fact the RDF will act as kind of an assistant to the Osmolator.

If the overspray is more than evap, we will have to find ways around that.

Also there will be small amounts of salt exiting the system from saltwater sticking to the drum each spray cycle. It would be interesting to know if that is a significant enough amount to affect salinity, or if like a 10% monthly water change would make it irrelevant.

The unit does come with a lid, but we will see how good it is and how things work out!

 

[xaflatoonx]

amazing build - following - i love the dimensions.

 

[Mortie31]

Bead filters are a bit less popular than they used to be. They require maintenance to flush them, and a lot of extra energy for the head pressure to force water through them. An RDF will filter 70 microns with massive flow with no maintenance and can be gravity fed. A bead filter will however filter super fine particles. But as long as I am getting the same or better than filter socks, I'm happy!

The actual spray part will be reverse osmosis water, not salt water. Almost all of the sprayed water passes through the screen and out to waste.

There will be some overspray, which is where we will test to see how it affects salinity. As long as the amount of overspray during the day is always less than the evaporation on the tank for that day, there will be no affect on salinity. In fact the RDF will act as kind of an assistant to the Osmolator.

If the overspray is more than evap, we will have to find ways around that.

Also there will be small amounts of salt exiting the system from saltwater sticking to the drum each spray cycle. It would be interesting to know if that is a significant enough amount to affect salinity, or if like a 10% monthly water change would make it irrelevant.

The unit does come with a lid, but we will see how good it is and how things work out!

Sounds excellent, I didn’t realise the spraying was done with RO water, I used to have an old version on my koi pond and it worked really well, I now use K1, I personally love my 2 bead filters and would love to see how one performed in salt water, maybe if I win the lottery, I’ll be following along, good to see some innovation.

 

[vetteguy53081]

What a way to plan and envision. This will be a winner.
Love the home..... almost forgot subject was tank

 

[Joel B in FL]

This is an extremely interesting concept. I look forward to seeing you implement it.

 

[JoannaLola]

Looks amazing !!
Love the aquascape already!

 

[McPuff]

It's hard to tell from the video... when the self cleaning cycle is underway, where does the particulate matter go? Looks like it would simply be sprayed back into input water "tank", waiting to go through the barrel filter again. I'll see if I can find some more information on it. Intriguing for sure.

 

[blitzkragz]

It's hard to tell from the video... when the self cleaning cycle is underway, where does the particulate matter go? Looks like it would simply be sprayed back into input water "tank", waiting to go through the barrel filter again. I'll see if I can find some more information on it. Intriguing for sure.

When the drum rotates, it brings the particulate matter sticking to it to the top of the filter, where it is sprayed down into a waste tray, and the waste tray is plumbed to drain. I.e. it goes to "the sewer", the same place water your in your slop sink would go. Or you could even just aim the waste tray at the slop sink.

In that video around 0:10 it shows 3 pipes. The one in the top middle is the waste tray drain. The two on the lower sides are water coming from the display tank. Then on the other side of the filter are two more pipes for clean water to return to the display tank.

 

[McPuff]

When the drum rotates, it brings the particulate matter sticking to it to the top of the filter, where it is sprayed down into a waste tray, and the waste tray is plumbed to drain. I.e. it goes to "the sewer", the same place water your in your slop sink would go. Or you could even just aim the waste tray at the slop sink.

In that video around 0:10 it shows 3 pipes. The one in the top middle is the waste tray drain. The two on the lower sides are water coming from the display tank. Then on the other side of the filter are two more pipes for clean water to return to the display tank.

I understand the first part... the sediment that is forced through the filter screen gets sent to the sewer. But what happens to the larger pieces of debris that just get blown off the barrel? They go back down into the holding tank, waiting to get stuck to the drum again, don't they? That was my main question. I assume you'd need to manual remove this once in a while. Not really applicable for reef but for pond I imagine it would need to be fairly often.

As for the second part of your answer, how is water directed to the 3 drain pipes? Is the trough just "floating" in the middle of the drum to remove the waste water (i.e., the rinse cycle) and the other two remove the water that would fall through the barrel and beneath the trough? Trying to visualize it and this seems logical to me. Thanks!

 

[i_declare_bankruptcy]

Wow! Folllowing! This is crazy!

 

[Ultra Aquatics]

Definitely following this. I love builds that push limits and try new things like this! Great job!

 

[blitzkragz]

I understand the first part... the sediment that is forced through the filter screen gets sent to the sewer. But what happens to the larger pieces of debris that just get blown off the barrel? They go back down into the holding tank, waiting to get stuck to the drum again, don't they? That was my main question. I assume you'd need to manual remove this once in a while. Not really applicable for reef but for pond I imagine it would need to be fairly often.

As for the second part of your answer, how is water directed to the 3 drain pipes? Is the trough just "floating" in the middle of the drum to remove the waste water (i.e., the rinse cycle) and the other two remove the water that would fall through the barrel and beneath the trough? Trying to visualize it and this seems logical to me. Thanks!

Think of the screen drum as a giant filter sock turned on its side. There is no sediment being forced through the filter screen. The sediment is trapped inside of the screen drum. One end of the drum is completely closed. The other end is where "dirty" water comes in. The water has to pass through the screen of the drum to continue on its way. What is left behind inside of the drum is the sediment. Then the drum rotates, and that sediment sticking to the inside of the drum is lifted up and out of the water, into the air, and sprayed down into the tray and exits the system.

It should be able to handle even larger pieces of debris like oak leaves up to an extent (even though not really applicable to a reef tank). But a massive influx of larger permanently floating things like acorns or sticks might have to be dealt with. You can see big chunks of stuff in that video coming out of the chute.

There is another kind of relatively obscure filter, that if I were going to build an outdoor pond under trees I would choose over an RDF, in German they call it "endlosbandfilter". That gives you the benefits of an RDF, but it can handle massive amounts of leaves. Its basically a conveyor belt, the belt being a screen that gets sprayed off. Even more expensive than an RDF, and not necessary here.

There is only 1 drain pipe, not 3 (the top middle is the drain) . The other 2 pipes below it are incoming water (needing to be filtered) from display tank. Then there are 2 more pipes on the other side of the filter for the cleaned water that has passed through the filter to exit and go back to display tank. So a total of 5 pipes. Yes, the trough is just "floating" in the top middle of the drum, where it is in the air.

 

[McPuff]

Think of the screen drum as a giant spinning filter sock. There is no sediment being forced through the filter screen. The sediment is trapped inside of the screen drum. One end of the drum is completely closed. The other end is where "dirty" water comes in. The water has to pass through the screen of the drum to continue on its way. What is left behind inside of the drum is the sediment. Then the drum rotates, and that sediment sticking to the inside of the drum is lifted up and out of the water, into the air, and sprayed down into the tray and exits the system.

Ok, now I feel dumb... it is the opposite of what I was thinking. After reading this description I totally understand and now it appears totally logical. Good golly. Thanks! :0)

 

[blitzkragz]

Exciting news, the tank should arrive next week! A lot of work has been done on various fronts of the build over the last several weeks. I had a an engineer spec the floor, he said there was no danger of the tank ending up in the basement but I might want to add some reinforcement to prevent any sagging. So I had "real" welder come and weld a steel I-beam from an existing post to an existing I-beam directly under the tank.

I have the steel frame for the stand welded up. Making sure such a large structure was perfectly flat and square was going to be difficult, and I don't have a large BuildPro table, so I got some "Monster Squares" from fireballtool.com that did the trick.

The stand will be faced with Ikea Ringhult gloss white cabinet doors, which will match our kitchen. You could call me obsessed with Ringhult, I just love the way it stays clean and looks great. I spaced the steel bars out so that standard 24" wide Ringhult doors can be affixed in those intervals.


I also ordered a bunch of titanium hardware to replace the 304 stainless on the RDF. So far I have the necessary screws/bolts/washers from alliedtitanium.com. I ordered a custom sized titanium plate from onlinemetals.com. And finally there are a couple tricky custom axles that I am going to machine on a lathe myself out of Derlin. More on that later.

 

[blitzkragz]

White Kessil a360x's, whaaat? Throwing caution into the wind and likely voiding the warranty on the Kessils to get the look I want. The plastic outer housing is easy enough to remove for painting, but requires snipping the power cable.

Which works out, as I planned on cutting the standard cables anyway. I really wanted them to have a minimalist profile. The outer coating of the standard black 18awg 300v power connectors they come with would prevent that because they add a ton of bulk, so I am rewiring them with normal 18awg 300v wire without the outer coating so everything will fit inside 3/4" aluminum tubing.

Shout out to Kessil though -- I accidentally dropped one of the power bricks (not a light, they were fine, just the black box) into a bucket of water and it fried it. I asked Kessil if i could buy another, but they sent one out for free!

 

[Anirban]

White Kessil a360x's, whaaat? Throwing caution into the wind and likely voiding the warranty on the Kessils to get the look I want. The plastic outer housing is easy enough to remove for painting, but requires snipping the power cable.

Which works out, as I planned on cutting the standard cables anyway. I really wanted them to have a minimalist profile. The outer coating of the standard black 18awg 300v power connectors they come with would prevent that because they add a ton of bulk, so I am rewiring them with standard 18awg 300v wire without the outer coating so everything will fit inside 3/4" aluminum tubing.

Shout out to Kessil though -- I accidentally dropped one of the power bricks (not a light, they were fine, just the black box) into a bucket of water and it fried it. I asked Kessil if i could buy another, but they sent one out for free!

They are looking great