RDSB/REFIGIUM nitrate reducer?

[jason the filter freak]

Ok I need some judgement and constructive critism and ideas and comments related to my design not art work!

 

I need to reduce nitrates, I have no money for a Nitraban reactor, and have no place for a hang on refigum, and I'm not about to pour vodka or sugar in my tank. So here my idea, ask me any questions and I'll try to describe my convolution as best as possible. The olny place I have room is under my tank, and I have very little at that, it's a 55 gallon.

 

 

Let me know

[davelin315]

I added some comments to the gallery, but just found this one.

 

The baffles over the sand bed/going through the sand bed are puzzling me. The purpose of baffles is to disperse the water flow, remove air bubbles, or to isolate one area and keep other areas' water level constant. The way you have it drawn, your sand bed is divided by the baffles into 3 areas. Since a refugium is typically lower flow, I'd suggest that you dispense with the baffles completely or have all of them at the right side of your refugium before the tank return. Is this also a sump for you, by the way? If this is your entire sump, you have no room for equipment in there. Consider what you want to put into the sump besides the refugium, isolate the refugium from the rest of the tank, and then figure out how you want to put your baffles in. Since your return area is on the right, if you isolate that with a baffle you'll keep the water level constant in all areas to the left and therefore know when you need to top off (or you can add an auto top off there).

[dbartco]

As long as the baffles are not there to "force" the water through the sandbed, seems fine. Nitrate reduction should work more by osmosis, and not flow.

[jason the filter freak]

Thanks so much for replying! The olny reason i had the baffles (the would be drilled like swiss cheese) drawn in there was to keep the refigium contents in place... I plan to have fairly fast water flow moving though the bed. I already have a sump with bio balls that will run my tank just fine. I need to get rid of my nitrates, while conserving space and budgets. Any more ideas.... comments?

[davelin315]

I think you're being counterproductive with bioballs and a DSB. Ditch the bioballs and go with the sandbed only.

 

Also, with high flow, you'll reduce the effectiveness of the refugium portion of your tank. The more contact time, the better. A traditional refugium is to serve as a refuge for small critters, so high flow will reduce their numbers in there. Adding macroalgae as a denitrator will also be less effective (from what I've come to understand) in a high flow area.

[jason the filter freak]

Ok I'm glad I'm getting feed back... I'll put a smaller pump and a sponge prefilter over the intake for the pump to help slow down water flow... As for the bio balls, I still need those to cut my amonia and nitrites right? I mean I spend more than $160 on the bio ball sump, and it's also the olny place I can add a protien skimmer to the system. I think having the baffels will also help slow down the water flow.

 

Any more suggestions?

[phisigs79]

If you have live rock IMO you wasted $160 on that sump. you dont need bioballs. Correct me if i am wrong but werent bioballs for fish only tanks without live rock? As for the swiss cheese baffles, macro will clog these holes eventully and you will over flow it. I say dont do this dsb idea in your sump, add two baflles way below the tank (that overflow over the edge instead of the swiss cheese idea), make a compartment for macro and one for skimmer/heaters and your done. As long as you have a good skimmer and dont overfload your tank with fish, you will be ok.

[Guest Lles]

Why not just use a RDSB? Otherwise known as a deep sand bed in a bucket. Take a 5 gallon bucket, fill with 12-18 inches of sand. Pipe in overflow from your tank in one end, and have the outflow into your sump from the other. If you have the room, it's a pretty cheap and effective way to cut down on nitrates. Only tricks i've learned is to 1. Keep the flow in the bucket moving pretty good as you dont' want alot of detrius to settle inside nad 2. always keep the RDSB covered from light.

[davelin315]

Just remove the bio-balls and continue to use the sump. If it's a traditional trickle filter with a drip plate it'll serve as a great place for gas exchange as the water is obviously going to be very agitated in there. I used to have a couple of Oceanic trickle filters and removed the media from them. I then filled these compartments with live rock rubble so that it all remained submerged in the water and eventually grew an outstanding sediment filter because of all of the sponges that grew in between the rubble. This way you can also use your skimmer compartment in there and you could even, if you're able to depending on your sump design, use this as a refugium or DSB area. Post a picture of your existing sump and go from there.

 

Also, as I think was suggested by Chris, don't overthink this. Simplicity is the best way to go. You're overcomplicating this by trying to do a bunch of things. Figure out what you want to do and then think of the easiest way to do it. Reminds me of trying to build my own trickle filter in college - kind of a build a better mousetrap thing. I had multiple baffles and each baffle held bioballs that were receiving new water that was supposed to be aerated. My final contraption was a mess, didn't work very well, and ended up cracking for some unknown reason and leaking a bunch of water through to the basement apartment of the house I lived in.

[phisigs79]

Why not do a RDSB? I think the issue here isnt a sand bed but more of a skimmer issue than anything. Cheap skimmer = nitrate problems. I have been there before and a better skimmer and fine sand (2 inches i might add) fixed my problem.

[jason the filter freak]

OK, whe I get the money I scrap the bio alls and pur inplcae the LR, should I treat it like bio balls and have water trickling over it....? Ohter wise whats the best way to raise the waterlevel in the sump?

 

Next it looks like I'll just build a seerate RSDB and refugium.... Nooo idea how i'll do this with the amout of space I have, but I'll manage.

 

Any other recomendations?

 

Well and build that 5 foot down draft skimmer I've been looking at.

[davelin315]

OK, whe I get the money I scrap the bio alls and pur inplcae the LR, should I treat it like bio balls and have water trickling over it....? Ohter wise whats the best way to raise the waterlevel in the sump?

 

No, keep it submerged under water. You don't want it be all aerobic (with oxygen) respiration, you want it to be a mixture. If you have water trickling over it, you'll probably lose a lot of the anaerobic respiration that goes on inside rock and also will probably not have as effective a filter as far as LR is concerned.

 

Next it looks like I'll just build a seerate RSDB and refugium.... Nooo idea how i'll do this with the amout of space I have, but I'll manage.

 

Check out the size of a RDSB. Again, there's some literature out there on the minimum size you need for it to be effective (I thought it was something in the neighborhood of 12"x30" or some random figure like that). If you've got room, I used to have a 60 gallon rubbermaid stock tank that I poured a bunch of sand in and had mangroves growing in. It was an awesome set up for a refugium and DSB, but it was also large and was part of a huge system in my basement.

 

As far as a refugium, you really don't need anything very large. Heck, if you add LR in place of bioballs that itself would be refugium as it will harbor microfauna without large predators.

 

Any other recomendations?

 

Use the 55 as your sump, but section it off. I've got a 150 gallon that I bought with my tank that I can take pictures of so you can see what the sump configuration is. It's got room in the middle for a DSB/refugium, although I'm thinking that that's where I'll put my skimmer instead. It's got baffles on either end so you can see what the ideal configuration is (not exact, but for your purposes).

[xCGx]

Why not do a RDSB? I think the issue here isnt a sand bed but more of a skimmer issue than anything. Cheap skimmer = nitrate problems. I have been there before and a better skimmer and fine sand (2 inches i might add) fixed my problem.

 

 

I have a euroreef and a two inch sand bed...I wasn't able to reduce my nitrates until I added the RDSB.

RDSB=0 trates so far.

[phisigs79]

I have a euroreef and a two inch sand bed...I wasn't able to reduce my nitrates until I added the RDSB.

RDSB=0 trates so far.

 

 

DID YOU FEED ALOT OR HAVE ALOT OF FISH?

[xCGx]

Neither...and tons of live rock. I also use RO water for both water changes and top off. At first I didn't for top off and my tap has a modrate level of nitrates. I think it was a cobination of things, like using RO water, macro algae and good water flow. I know that denitrification (sp?) doesn't happen unless the sand is deep enough so I would contribute the RDSB for the lower trates.

[traveller7]

I use a 20gal rubbermaid brute sitting in my 100gal rubbermaid stock tank filled with 160lbs of aragonite sand in a remote DSB config. Wiped out a nasty hair algae issue within 45 days.

 

fwiw: tank is 315gals, lots of fish, low amount of live rock by reef standards, lots of overfeeding of fish and anemones, and bare bottom.

[jason the filter freak]

OK LET ME CLARIFY .... I have a complete and utter lack of space, dorm sized room I have olny the space under my 55 gallon wich is about 44 inches, and already 21 inches of that is taken up by a sump.

 

Here's a pic the member who formerly owed this tank took, note, in my case it sits about 4 inches off the wall.

Edited August 24, 2006 by jason the filter freak

[Rascal]

I am having a little trouble visualizing your set up, but if you are planning on having 2 separate containers (1 sump and 1 refugium) each being fed by its own overflow pipe from your tank and each returning to the tank with its own pump, I would definitely NOT recommend that. Recipe for a flood if you ask me. Don't know if that is what you had in mind or not but I thought I'd mention it just in case.

 

If you are going to have a separate sump and dsb/refugium, I would recommend just having the latter feed into the return area of your sump with it's own overflow/drain. You wouldn't even need to add anything to your existing tank. Just tee off the overflow that now goes into the sump and then put a ball or gate valve on the pipe leading to the DSB/fuge to get the desired flow. This way you will not have to worry about creating a sand storm, etc. . .

 

Another option would be to scrap the existing sump and just get or build as big a container as will fit under your tank, then divide it up with baffles. A couple of ways to do this. You could have 3 compartments - 1 to receive the overflow from your tank, break up bubbles, and perhaps place a skimmer and/or any other filtration you choose to use; the 2nd to act as your DSB/Fuge; and then a 3rd to feed the return pump. Another (and IMO better) way would be to have 2 compartments, and basically set it up the way I described above for 2 separate containers. 1 compartment would act as your sump - containing all filtration and the return, and the 2nd would be your DSB/Fuge. So some of the overflow water would go directly to your sump, and some would go to the Fuge and then overflow into the sump area. Again, just tee off your overflow and fiddle with it until you get the right flow balance between how much goes through the fuge and how much straight into the sump.

 

Finally, I heartily agree with the recommendations above re: Bio Balls (Nitrate factory - ditch them); relying on live rock for your biological filtration (I assume you already have enough in your tank, but more in the sump and/or fuge couldn't hurt), getting a good skimmer; and the utility of adding some sort of DSB for nitrate reduction. IME it may take a few weeks to see the results, but once it kicks in it does a great job of reducing nitrates.

 

One last comment re: cost. Don't underestimate the cost of setting up an effective DSB/Fuge. Done right, the sand is not cheap (at least not any I could find!) and you will need quite a bit of it. IMO you would also benefit from populating with some critters (nassarius snails, brittle stars, kits like those from IPSF or GARF).

 

Hope this helps.

[jason the filter freak]

A DSB was suposed to be a cheap alternative, i think I'll have to draw water from my sum, and then loop back into my sump. Live rock is expensive as H-E-double hocky sticks, thowign out the bio balls, is not an option for me. At least not yet, I will however when i have the money for alot of extra LR. My fuge area is gowing smaller with every suggestion that people make, but I have some ideas... speaking of which where is a good place to get the substrate for a refigium?

[phisigs79]

IMO Do it right or dont do it at all. Why dont you wait until you get some money then buy a skimmer, live rock and DSB and be done with this.

[jason the filter freak]

I'll get the skimmer asap, and the DSB mod looks pretty cheap, a 5 gallon bucket with a lid, a return line, and some sand looks pretty cheap.

[davelin315]

I'll get the skimmer asap, and the DSB mod looks pretty cheap, a 5 gallon bucket with a lid, a return line, and some sand looks pretty cheap.

 

Not true. Aragonite sand is more expensive than your general run of the mill sand and it's harder and harder to come by cheap (no more Southdown/Old Kastle anywhere to be found). You could of course use other types of sand such as aragonite from the hardware store (concrete section), but again, it's harder and harder to find it. You could also use silica sand, but there's lots of debate on it, some swear by it and the amount of microfauna it supports, others think it kills microfauna. I'm not educated enough in its use to say one way or the other.

 

Also, again (I know, I'm beating a dead horse), check out what the minimum size for a DSB is. I don't think that a 5 gallon bucket will give you what you need. Plus, a sandbed without the proper inhabitants will simply bond together into a solid mass, defeating the purpose.

[YBeNormal]

Also, again (I know, I'm beating a dead horse), check out what the minimum size for a DSB is. I don't think that a 5 gallon bucket will give you what you need. Plus, a sandbed without the proper inhabitants will simply bond together into a solid mass, defeating the purpose.

 

Excerpt from a post by Anthony Calfo in this MEGA thread titled "DSB in a bucket for nitrate control" at RC:

it is a modest strategy and dependant on bioload of course. But so cheap to employ, and easy to remove if you don't like it.

 

My LFS finally tried this with a 55 gall tank full (nearly to the top) of sand with a good stream of water traversing the length of the tank. It was staggering how fast it reduced nitrates on a nearly 2K gallon system.

 

A 5 gallon bucket with a 60lb bag of sand filling it can do similar/remarkable work on say a 90-120 gallon tank. A larger plastic garbage can (kitchen size... 20 gall or so) with a couple hundred lbs of sand, etc.

 

The goal here is denitrification and buffering (if using aragonite).

 

There are not many other benefits... and not many risks either. Unlit and with a strong stream of water over it, its a fairly brainless application Cover it and keep it dark... there is little to maintenance to speak of for it. You can imagine that with the good water flow (key) or even mechanically prefiltered water... there is no way for this to practically become a nutrient sink, as the small fast volume of water cruising over it do not allow the settling/sinking of much solid matter over time.

[xCGx]

I have a 90 bowfront so my tank is the same length as yours but is bowed therefore I don't have the room on the ends because it is narrower. I had to place a 20 gallon high right in the middle of the stand which takes up 24 inches of space. I was able to squeeze a 5 gallon bucket in there.

 

 

 

the pic is larger in my gallery.

[jason the filter freak]

EDIT: NEW DESIGN