is there any advantage (besides cost) to using a RDsb in a bucket rather than a 20g fuge style setup with cheato and a 6"dsb? whats the real difference in action?

Well from the first few pages of this thread, the purpose of having it in a bucket (covered with no light) is to prevent algae growth within the RDSB. If you were to have a normal DSB in a fuge with chaeto, you would need to have a light on it which would cause algae growth. Furthermore, by having it in a bucket, you can easily take it offline, switch it out for a new RDSB after a few years, place it virtually anywhere you have room for it, etc..

looking at the big picture though,a DSB is a DSB, and the results will essentially be the same: (with some variation due to flow, bioload, size, etc.) lower nitrates.
I chose to go your route steve, and I have a 29 gallon fuge which I partitioned off in the middle, with a 12" deep sand bed on one side, and chaeto growing in the other. the water has to flow over the DSB to exit the fuge, and I keep a piece of opaque acrylic over the sand bed portion to minimize algae build up in that section. my DSB is 15" x 11.5" by 12" deep. this is actuallly a larger surface area than a bucket would provide, which is one advantage over the bucket.

Steve, after I posted in your other thread on this topic I thought I would add my set up to this forum for others to see/comment on.

[IMG]http://i35.photobucket.com/albums/d166/mille239/DSB.jpg[/IMG]

Ok, so I'm considering doing this with my new barebottom 50G tank in combination with a 20G sump/fuge filled with Chaetomorpha with a fairly light fish load. My question, what's the minimum flow you could use with a 5G bucket mostly full of sand? Could you use an aqualifter, which I believe maxes out at 5gph? I was thinking just drawing in water from the refugium (where the flow is low and most detritus will have already settled). I ask because I have one lying around and if I have to buy a pump for the DSB it goes down the list of priorities (other priorities being things like lights).

I'm not sure what the minimum is, but the problem is keeping the sand bed clean.

How are people going about this?

I'm thinking of plumbing two phosban reactors to the rdsb, a carbon one before, and a phosphate absorbing media afterwards.

Since the phosphate media needs about 80gph, I think plumbing it with a 150gph pump or so will do the trick.

I'm also thinking of doing a closed loop in the RDSB so that nothing collects on the sand. Maybe a MJ1200. It'll basically recirculate the water, while the actual water flow through is very low.

I am going to have to wait on my little experiment. There is a 7.5 foot Christmas tree standing in my way now. Yes it was a wife intervention that has caused a delay. However I thought of a different container in case anyone is interested. Our diaper pail is hard plastic and two of the sides are flat so a normal bulkhead should work. I think they are about $10 at the store too.

An aqualifter is insufficent. I use an Eheim 1250 (312 gph) and it is perfect. I too used a container with flat sides although there are ways around that problem even with a bucket.

However I use a chaeto refugium connected to a remote deep sand bed. I don't think you want to combine them as keeping the sand clean is problematical.

I just made a RDSB! I basically took a square 4 gallon bucket with lid I bought from usplastics.com, and drilled two holes on opposite sides. I found insert fitting bulkheads at my LFS today at 3/4", and a reducer. So I got all of that and I will be hooking up some pump that has a 1/2" outlet to it and dumping it out back into the tank, or maybe I'll hook it up inline with another phosphate reactor.

I first drilled the holes for the 3/4" Bulkheads, then I took a dremel with a grinder and grinded flat the "ribs" that went where the bulkhead was. Once that was done, I just had to do some vinyl tubing for the intake. I need 1/2" vinyl tubing and some 3/4" to finish it off tomorrow. I'll probably hook it up to a MJ900 that I have to digup somewhere. This will start reducing my nitrates soon!

[img]http://farm3.static.flickr.com/2034/2092298047_8414ce25cc.jpg[/img]

[img]http://farm3.static.flickr.com/2158/2093076372_3db5892725.jpg[/img]

[img]http://farm3.static.flickr.com/2133/2093076610_84b6d421bc.jpg[/img]

[img]http://farm3.static.flickr.com/2148/2092297443_6493c63b9c.jpg[/img]


I'm currently chemical dosing my tank for it to cycle. I dose 8ppm of ammonia daily. Ammonia is falling to undetectable rates within a day now, nitrites within 2 days, nitrates are currently off the charts (>50ppm lol).

I've been cycling this way since October with all dead dry rock (no seeding of any kind except Marineland Bio-Spira once in November).

I'll let you guys know how it brings my levels down.

[QUOTE][i]<a href=showthread.php?s=&postid=11271076#post11271076 target=_blank>Originally posted</a> by morbid0000 [/i]
[B]100gal reef
6gal glass carboy filled 3/4 with sand [tubing through rubber plug, carboy in a black bag to block light] and fed by maxijet 1200
Running since 01/05 with no sand changes
Initial nitrates 80
Current nitrates 40
RDSB output nitrates 0
I love this thing. [/B][/QUOTE]

These are the posts that I like to see, but I must be missing something in your design. What is the through put rate? Is it 300 GPH from your 1200 Maxijet?

What I don't understand is, how can your nitrate drop 40 ppm with such a fast flow through?

If 40 ppm water can pass through/over 5 gallons of sand at a rate of 300 GPH (3 times the volume of your tank per hour in this case), then how does it climb back up to 40 ppm so quickly? If this were true, one could assume your nitrate would escalate up into the hundreds if you took the filter off-line.

Ok so I have read quite a bit of this thread, I currently have a 5G hex tank setup as a mini fuge on my system. I plan to upgrade and this tank was going to be removed but now I plan to use it as a RDSB. I have quite a bit of CaribSea Aragamax Sugar-Sized Reef Sand in my display tank, when I move this tank to the new upgraded tank I plan to use a larger sand bed in the display (sugar size sand is such a pain with high flow). I am assuming I can rinse this sand and then use it for the RDSB?

Sugar sized sand is ideal for RDSB, at least 5 inches in depth, preferably with good flow and no light. I pass 300 GPH over mine with 3 inches of water.

[QUOTE][i]<a href=showthread.php?s=&postid=11349608#post11349608 target=_blank>Originally posted</a> by snorvich [/i]
[B]Sugar sized sand is ideal for RDSB, at least 5 inches in depth, preferably with good flow and no light. I pass 300 GPH over mine with 3 inches of water. [/B][/QUOTE]

Yeah its great for everything except my display tank :) So is it ok to use live sand or should I rinse it first?

I rinsed mine. Remember you don't want things growing in there other than denitrification bacteria. They will grow on their own.

[QUOTE][i]<a href=showthread.php?s=&postid=11349707#post11349707 target=_blank>Originally posted</a> by snorvich [/i]
[B]I rinsed mine. Remember you don't want things growing in there other than denitrification bacteria. They will grow on their own. [/B][/QUOTE]

Perfect so this modification will only cost me time :)

Yes, that is right. Remember, only about 3 inches of water and the rest sand. Pass about 300 gph or thereabouts over it. If possible keep it as dark as possible so nothing grows.

While rinsing the sand costs only effort, in my case, I had a LOT of sand as I have two 14 gallon RDSB and I was pretty tired at the end.

[QUOTE][i]<a href=showthread.php?s=&postid=11349809#post11349809 target=_blank>Originally posted</a> by snorvich [/i]
[B]Yes, that is right. Remember, only about 3 inches of water and the rest sand. Pass about 300 gph or thereabouts over it. If possible keep it as dark as possible so nothing grows.

While rinsing the sand costs only effort, in my case, I had a LOT of sand as I have two 14 gallon RDSB and I was pretty tired at the end. [/B][/QUOTE]

Did you wash sugar sized sand? If you havent tried that its good training for bar tendering in Dublin......

It is good training for a sore back and hot shower. Yes, I washed 10 bags of sugar sand.

[QUOTE]What I don't understand is, how can your nitrate drop 40 ppm with such a fast flow through?[/QUOTE]

I was thinking the same thing.

The number just don't add up here.

I think this remote DSD stuff is all a bit a pipe dream

[QUOTE][i]<a href=showthread.php?s=&postid=11352675#post11352675 target=_blank>Originally posted</a> by waynem [/i]
[B]I think this remote DSD stuff is all a bit a pipe dream [/B][/QUOTE]

do you think that DSB's are a pipe dream too or just if they are installed remotely?

No just the "remote" as a way to dramatically reduce nitrate.

I am not say they will not work, just not as well as most people seem to hope they will. It's no golden bullet.

As part of a overall system package it would be of some help (IMO) when used in conjunction with other methods such as a fudge.

I had DSB in my last tank, this time I don't have one. I do however have a sulphate nitrate filter. That works really really well, takes time to setup and can be fiddly, but the results are good and easy to see with a test kit (at the return) and after a few months on the tank I have readings of 0 down from 20

[QUOTE] [B]waynem[/B] As part of a overall system package it would be of some help (IMO) when used in conjunction with other methods such as a fudge.[/QUOTE]

Well there has been some stir on these boards about dosing sugar to reduce nitrates, but I don't know if I'd go so far as to put fudge in my tank. :p

[QUOTE][i]<a href=showthread.php?s=&postid=11353646#post11353646 target=_blank>Originally posted</a> by waynem [/i]
[B]No just the "remote" as a way to dramatically reduce nitrate.

I am not say they will not work, just not as well as most people seem to hope they will. It's no golden bullet.

As part of a overall system package it would be of some help (IMO) when used in conjunction with other methods such as a fudge.

[/B][/QUOTE]
i agree completely and i think if we go back to the start of the thread this is definitely explained.


this is not a 5G miracle and the amount of denitrification is directly related to the size of the sand bed. this only works in conjunction with proper reef keeping techniques and cannot eliminate any of the normal methods used in this hobby. ( ie. running a skimmer, having LR, running a fuge ( though i really do like fudge :) ) with macro, proper maintenance and cleanliness, maintaining a reasonable bio-load, good feeding techniques etc...... )

I'm having a hard time reading through so many pages so I'll seek the advice of anyone still following this thread. 30 cube with a 10 gal sump/fuge. I like the idea of making the rdsb removable and I want to shove it somewhere in the sump. What's the minimum size container I should use? This is all in the planning stage right now. I was thinking about making something out of black acrylic or a cookie dough tub.

I'm kind of in the same situation jayson, still planning out my system. It seems to me that vertical depth is very important, I would try for at least 10" deep. The other dimensions are more variable but bigger is better of course. As an out of the blue estimate, perhaps 6x6x12" minimum? That's about 2 gallons. I'm trying to find a good container for mine like the square bucket Kinetic is using, so far I just have a 5G round paint bucket. Anyone else have some size suggestions?

Well, the minimum depth is 5 inches but remember that if you use argonite sugar sand over time it will dissolve and keep your PH up (a side benefit). I personally have a 14 gallon square canister that is 12 by 12 inches with almost 20 inches of sand.

Reading the entire thread is worthwhile. But if you think it will not work, don't do it.

There are no silver bullets in this hobby. I personally believe in good skimming, remote deep sand bed, ozone through a reactor not a skimmer, and carbon for removal of any residual ozone. There are a variety of refugium types (remote deep sand bed is one, algae filter is another, but there are more.

Thhere is value in reading and understanding why these techniques are effective; there is no free lunch and fudge is rarely provided although I do have a weakness for it. If you understand why something is purported to work, you can make an intelligent choice. If you simply dismiss it, it for sure will not work for you.