Controllable deep sand beds - a discussion thread

[Mortie31]

Now the question is, do you think I should replace the siporax with sand, in my reactor? I’ve read that potentially siporax leeches Silcate in low oxygen environments and am a bit concerned about it long term. If I did swap it out for sand what grain size would you recommend? The reactor has a volume of 13L

 

[Sallstrom]

Now the question is, do you think I should replace the siporax with sand, in my reactor? I’ve read that potentially siporax leeches Silcate in low oxygen environments and am a bit concerned about it long term. If I did swap it out for sand what grain size would you recommend? The reactor has a volume of 13L

We've had that experience and I know @Lasse also saw a large increase of silica, so I know two people that will say change to coral gravel

I would go for 10-15mm in your filter, same as a calcium reactor.

 

[Sense of nature]

same concept as a reverse UG filter ... mostly

 

[Dr. Dendrostein]

same concept as a reverse UG filter ... mostly

The flow very, very slow.

 

[Scrubber_steve]

Dymico's claim is that it replaces a calcium reactor (yes) & a protein skimmer. In regards to the skimmer what do they mean exactly?
Are they refering to a skimmers (indirect & weak) function as a method of inorganic nutrient control? Or a skimmers (poor) function as a method of DOC removal?
A Dymico system does not employ any method of direct DOC removal, & also claims water changes are unnecessary.
Perhaps Lasse & Sallstrom could shed some light on what happens with DOC in a system such as Dymico?

 

[Mortie31]

I decide to swap the siporax out I was starting to see more diatoms so silicate levels may of been rising. Filled the filter with coarse coral gravel and rock rubble.
.

A close up of the various inlets and outlets I added to the lid of the filter.... a probe holder, one for tank water in and DOC and bacteria.

I seeded with bacteria and some NOPOx

 

[Mortie31]

Following setting up this coral sand and rock rubble recirculating reactor last Thursday, dosing 8ml/ day of NOPOx and a through water drop rate of 1/Sec, over the weekend the redox plummeted as did the nitrate levels, it is already zero, 20 in my tank, however I think I’ve reduced the redox to far as I can smell hydrogen sulphide so increasing water flow and keeping an eye on it.

 

[Dr. Dendrostein]

It's alive, it's alive

 

[Dr. Dendrostein]

Following setting up this coral sand and rock rubble recirculating reactor last Thursday, dosing 8ml/ day of NOPOx and a through water drop rate of 1/Sec, over the weekend the redox plummeted as did the nitrate levels, it is already zero, 20 in my tank, however I think I’ve reduced the redox to far as I can smell hydrogen sulphide so increasing water flow and keeping an eye on it.

Was sand and rock, seeded already ? Curious

 

[Mortie31]

Was sand and rock, seeded already ? Curious

No it wasn’t, it was dry, but I gave it a head start with a good dose of BR7 bacteria and NOPO, and it really caught me unawares as it took over a week for the redox to drop to -200mv when I was using sipromax.

 

[Mortie31]

I’m not sure of the science behind this, why would the coarse sand and rubble start so quickly, as compared to sipromax? other denitrators use sulphide, however I want this to be a DOC fuelled, anaerobic filter, so going to flush it through until the redox is -150mv and try to hold it there, I might also have to reduce the amount of DOC I’m adding.

 

[Dr. Dendrostein]

@Sallstrom, here small dymico copy. Very small , if it works 75-200 gallon tank?

 

[Dennis Cartier]

@Jomama that is a cool little Dymico style filter. I love it. Where did you see it?

I have been working on one as well, though stalled at the moment, but am still planning to finish it and use it on my 560 G DT that I have underway. The outside bottom pipes (with the 45 degree bends) will be replaced with straight through ones as I can't get a pipe cleaner to pass the bend. The bends where added when I realized that the spacing was wrong on the outside bottom holes and the pipes should be positioned further outboard. Oh well, less optimal positioning but maintainable trumps optimal positioning, but unmaintainable.

This will be siliconed into a 75 gallon tank and gives 6" at each end for circulation and return pumps. The media bed section is 36" in length. This is, as far as I can tell, close to the same dimensions as the Dymico 2000 series filter.

Dennis

 

[Sallstrom]

@Sallstrom, here small dymico copy. Very small , if it works 75-200 gallon tank?

@Jomama that is a cool little Dymico style filter. I love it. Where did you see it?

I have been working on one as well, though stalled at the moment, but am still planning to finish it and use it on my 560 G DT that I have underway. The outside bottom pipes (with the 45 degree bends) will be replaced with straight through ones as I can't get a pipe cleaner to pass the bend. The bends where added when I realized that the spacing was wrong on the outside bottom holes and the pipes should be positioned further outboard. Oh well, less optimal positioning but maintainable trumps optimal positioning, but unmaintainable.

This will be siliconed into a 75 gallon tank and gives 6" at each end for circulation and return pumps. The media bed section is 36" in length. This is, as far as I can tell, close to the same dimensions as the Dymico 2000 series filter.

Dennis

Nice!
I glad that there are more than me looking into building their own version of this type of filter! I did a lot of research about this but it was 2-3 years ago, so I don't remember that well all the ideas. I'll try to find some old notes.
I don't know what size is enough for a certain volume.

/ David

 

[Dennis Cartier]

Nice!
I glad that there are more than me looking into building their own version of this type of filter! I did a lot of research about this but it was 2-3 years ago, so I don't remember that well all the ideas. I'll try to find some old notes.
I don't know what size is enough for a certain volume.

There are a couple of Dymico style filter users on here. The best tank that I have seen using a DIY version is @Squamosa so far.

The guidelines that Dymico state in their manual is, a filter volume of 10%+ of the tank volume. So looking at the filter I have partially complete, it mounts in a 75 G aquarium with a 6" compartment at each end. So this gives the central media compartment a volume of 75G/5' * 4' = 60 G. So this filter should be about perfect for my 560 G DT.

Dennis

 

[Sallstrom]

@Jomama that is a cool little Dymico style filter. I love it. Where did you see it?

I have been working on one as well, though stalled at the moment, but am still planning to finish it and use it on my 560 G DT that I have underway. The outside bottom pipes (with the 45 degree bends) will be replaced with straight through ones as I can't get a pipe cleaner to pass the bend. The bends where added when I realized that the spacing was wrong on the outside bottom holes and the pipes should be positioned further outboard. Oh well, less optimal positioning but maintainable trumps optimal positioning, but unmaintainable.

This will be siliconed into a 75 gallon tank and gives 6" at each end for circulation and return pumps. The media bed section is 36" in length. This is, as far as I can tell, close to the same dimensions as the Dymico 2000 series filter.

Dennis

Whould you like to share your idea of how the water flow will be in this filter? Will it be a closed water compartment in one end? Great build!

 

[Sallstrom]

Dymico's claim is that it replaces a calcium reactor (yes) & a protein skimmer. In regards to the skimmer what do they mean exactly?
Are they refering to a skimmers (indirect & weak) function as a method of inorganic nutrient control? Or a skimmers (poor) function as a method of DOC removal?
A Dymico system does not employ any method of direct DOC removal, & also claims water changes are unnecessary.
Perhaps Lasse & Sallstrom could shed some light on what happens with DOC in a system such as Dymico?

Sorry, thought I had this thread on my watch list but it wasn't. So I've missed some posts!

I think DyMiCo added a skimmer to their systems, or at least I've seen a system with both somewhere online the last year. Not the best reference, I know Perhaps we can find someone here on R2R with a bought DyMiCo filter?
So I think some of their claims in the beginning were a bit exaggerated. Like many outher systems like Jaubert etc But still good ideas which could be included in a life support system.

/ David

 

[Sallstrom]

Following setting up this coral sand and rock rubble recirculating reactor last Thursday, dosing 8ml/ day of NOPOx and a through water drop rate of 1/Sec, over the weekend the redox plummeted as did the nitrate levels, it is already zero, 20 in my tank, however I think I’ve reduced the redox to far as I can smell hydrogen sulphide so increasing water flow and keeping an eye on it.

Great work!

Any news? Does it work well so far? Do you get a lot of bacteria out from the filter or not?

 

[Dennis Cartier]

Whould you like to share your idea of how the water flow will be in this filter? Will it be a closed water compartment in one end? Great build!

Sure, this module will be siliconed into a 75 G tank (60" x 18" x 21"), so this will provide 3 compartments inside the 75 G tank. One of the end compartments (6" x 18" x 21") will have a circulation pump (Sicce 2.5/3.0). The 2 outside bottom pipes will be open to this compartment and be the return from the filter bed. The 2 top pipes will be the output of the circulation pump and will be the feed to the filter bed. The bottom centre pipe will be plugged in this compartment.

The return section will be at the other end of the 75G and will be the same size as the section housing the circulation pump (6" x 18" x 21"). The bottom centre pipe will be the return from the filter bed and the other 4 pipes will be plugged at this end. The return pump will be pulling from the compartment, rather than directly from the pipe. I plan on putting a standpipe of the pipe feeding this compartment to help regulate the flow (and allow use of level sensors). I am thinking that a couple of level sensors in this compartment will form the foundation of a filter cycle. If the filter was only driven by an overflow from the DT, then this may not be needed, but I plan on still having a sump, so this filter will be too high to be purely overflow driven. A 3rd pump will be required in the sump to feed unfiltered water to the filter.

The planned filtration cycle will go something like this.

1. The return pump will activate and drain the return compartment until the level sensor triggers.
2. The feed pump in the sump will activate and fill the filter bed compartment. This will overflow through the stand pipe in the return compartment, triggering the high level sensor, which will disable the feed pump.

The time it takes to drain and fill the return compartment will be measured and tracked to help determine when the pumps and plumbing require maintenance. As the return compartment will hold the next batch of filtered water that will be returned on the next cycle, it will be a convenient place to measure parameters such as ORP and/or Oxygen level. An air stone and/or skimmer pump could be also placed here that can be activated to re-oxygenate the return water and/or adjust CO2 levels (if CO2 were to be used in the filter bed). I am also planning on investigating the possibility of placing an air stone in the circulation compartment that could be activated to help limit the lower end of the ORP range of the filter. The circulation compartment will also hold an ORP sensor as it will monitor the ORP of the filter bed.

Because my filter is designed to be operated in 'batch' style operation, my plan is to target n cycles per hour, with an expected maximum of 15 cycles per hour. The fixed cycle size forced by the level sensors and return pipe height, will also help to calculate the daily flow through the filter. Nitrate too low? Reduce the cycles per hour and control the filter efficiency using the air stone in the circulation compartment. This should also be a good way to prevent Hydrogen Sulphide production as well without having to resort to dosing of nitrate ( which seems counter productive).

Dennis

 

[Mortie31]

Great work!

Any news? Does it work well so far? Do you get a lot of bacteria out from the filter or not?

It’s been running a couple of weeks now, I’ve had to adjust the water flow to keep the ORP in the -100 to -250 range if I let it drop to low you get hydrogen sulphide, had it running at -150mv ish for 8 days now and 1 drop every 2 seconds output and just measured nitrates leaving the reactor and they are at 2ppm salifert, so still not completely converting to nitrogen, but nearly there, all being well another week or so and I’ll be at zero. I can see what I assume is nitrogen forming at the top of the cylinder so I have to vent this. I need to make a small adjustment to the outlet tube so this is pushed out moving forward. I’m not seeing any bacteria coming out of the filter as it’s running now, but if I lower the Orp I get a white snot like substance and can smell hydrogen sulphide but this is not what I want, which may be bacteria but I don’t know, I’m trying to avoid this and create nitrogen gas..