First post, setting up my new 90. RDSB question.

[tsprice82]

Hello WAMAS,

 

I recently joined after keeping a 75 gallon reef tank for a little more than one year. Lots of great information and discussion here on your site. I just bought a 90 gallon from another WAMAS member that I am now getting ready to set up.

 

I have a new skimmer on its way and new T5 6x54w fixture. I also bought a overflow kit from glass-holes.com and drilled my 90, it was super easy. I'm also going to drill my 75 and use it for a sump.

 

My question is this, I want to do a RDSB in a Rubbermaid tub, has anyone used one long enough to say that it really works? What flow rate is best? Anthony Calfo seems to say that it should be as high a rate as possible without washing the sand. What do you all think?

 

Thanks so much.

[Origami]

Hello WAMAS,

 

I recently joined after keeping a 75 gallon reef tank for a little more than one year. Lots of great information and discussion here on your site. I just bought a 90 gallon from another WAMAS member that I am now getting ready to set up.

 

I have a new skimmer on its way and new T5 6x54w fixture. I also bought a overflow kit from glass-holes.com and drilled my 90, it was super easy. I'm also going to drill my 75 and use it for a sump.

 

My question is this, I want to do a RDSB in a Rubbermaid tub, has anyone used one long enough to say that it really works? What flow rate is best? Anthony Calfo seems to say that it should be as high a rate as possible without washing the sand. What do you all think?

 

Thanks so much.

 

Hi Todd. I'm not sure that it needs to be "as high as possible." Though thee flow across the RDSB should be high enough to keep detritus in suspension and from settling out on the sand surface.

 

I'm a believer that RDSB's work. They do take a little time to reach their full potential as bacteria populate the deepest parts of the bed, but the science behind them seems to be solid.

Edited January 6, 2009 by Origami2547

[lanman]

Hi Todd. I'm not sure that it needs to be "as high as possible." Though thee flow across the RDSB should be high enough to keep detritus in suspension and from settling out on the sand surface.

 

I'm a believer that RDSB's work. They do take a little time to reach their full potential as bacteria populate the deepest parts of the bed, but the science behind them seems to be solid.

 

How long?? Mine has been up a couple of months now - and no measurable change, really. MIGHT be a little better; but not definitive yet.

 

bob

[Origami]

How long?? Mine has been up a couple of months now - and no measurable change, really. MIGHT be a little better; but not definitive yet.

 

bob

 

It's the cat litter, Bob.

 

Calfo says that you should see results in about a month or so. You're beyond that already.

 

When you started your RDSB implementation, Bob, I may have mentioned that I thought that maybe your bucket was a bit small for your system. You've got a really large system, and the bucket that you used seemed like it may have been undersized for the volume of water that you were processing as I recall. For example, I've read (http://reefcentral.com/forums/showthread.php?s=&threadid=595109) that for systems of 100 gallons or so, you could get away with about 60# of sand in a 5 gallon bucket, but that for larger systems you'd need something a larger. For now, in my system (which is still recovering from my recent tank upgrade), I've got around 100# of sand, 9 inches deep in my 'fuge with a surface area of about 288 square inches, and probably over 400# total in the system. My nitrates are at zero, but I don't know if it's because of the sand bed since I'm now skimming rather heavily and have macro algae growing, and probably have something on the order of 350# of live rock in my system overall. I can say that, for now, I'm not dosing carbon sources anymore as there doesn't seem to be the need any longer.

 

Still, it seems that you should have seen *some* reduction in nitrates, doesn't it?

Edited January 6, 2009 by Origami2547

[zygote2k]

I have a 40g DT, a 30g refugium, and a 24g rubbermaid sump with about 6" of aragamax. I placed a piece of eggcrate on top of the sand to support the return pump to the DT. The DT drains into the 'fuge, which drains into the sump/DSB. Before installing the DSB, I had 20 ppm nitrate and within a month, I had and still have zero. The return never stirs up the sand in the sump and I've noticed many types of worm tracks on the surface. The sump is covered and dark inside too.

[Larry Grenier]

Semi-hijacking

 

Does the RDSB need to be in the dark? Can it be the lower level of a macro-fuge or even under the rack of a frag tank?

[zygote2k]

I'm not an expert on DSB tech, but I think it's fine in the light or dark as long as excess detritus and algae don't clog the surface levels.

[Origami]

Semi-hijacking

 

Does the RDSB need to be in the dark? Can it be the lower level of a macro-fuge or even under the rack of a frag tank?

 

It is not necessary that it be kept in the dark. Darkness is a convenience that some use with their RDSB to stem the growth of algae, cyano or other photosynthetic nuisance forms. While DSB is short for Deep Sand Bed, RDSB can either stand for Remote Deep Sand Bed or Remote Deep Sand Bucket. The difference is in the implementation. The bucket implementation typically is nothing more than a deep container filled with a bunch of sand with a means to get water in and out. It can be either open or sealed, open to light or kept dark. You generally don't have macroalgae in the bucket implementation.

 

It is perfectly acceptable to keep a deep sand bed in a 'fuge. Mine is in a 20-high where the bottom half is sand and the upper half is macroalgae. You do want to keep the detritus from accumulating, and in my case (where flow really doesn't do the trick because of the macroalgae), I have a few crabs and such in the fuge to keep things clean.

Edited January 6, 2009 by Origami2547

[zoozilla]

It is not necessary that it be kept in the dark. Darkness is a convenience that some use with their RDSB to stem the growth of algae, cyano or other photosynthetic nuisance forms. While DSB is short for Deep Sand Bed, RDSB can either stand for Remote Deep Sand Bed or Remote Deep Sand Bucket. The difference is in the implementation. The bucket implementation typically is nothing more than a deep container filled with a bunch of sand with a means to get water in and out. It can be either open or sealed, open to light or kept dark. You generally don't have macroalgae in the bucket implementation.

 

It is perfectly acceptable to keep a deep sand bed in a 'fuge. Mine is in a 20-high where the bottom half is sand and the upper half is macroalgae. You do want to keep the detritus from accumulating, and in my case (where flow really doesn't do the trick because of the macroalgae), I have a few crabs and such in the fuge to keep things clean.

 

+1

[Grav]

I'm not huge on the RDSB or DSB theory. I've found that growing macro in that RDSB space provides more nitrate reduction than a RDSB can. However I do think they help, and certainly do no harm. My one warning is not to use a rubbermaid tub. If you are good at drilling glass anyway, get a cheap even used glass tank and use that.... they are far better at holding water for far longer.

 

How much $ would you need to save to make dumping the contents of your aquarium on the floor worth while?

[Origami]

I'm not huge on the RDSB or DSB theory. I've found that growing macro in that RDSB space provides more nitrate reduction than a RDSB can. However I do think they help, and certainly do no harm. My one warning is not to use a rubbermaid tub. If you are good at drilling glass anyway, get a cheap even used glass tank and use that.... they are far better at holding water for far longer.

 

How much $ would you need to save to make dumping the contents of your aquarium on the floor worth while?

 

Great point, Garrett. Consumer grade tubs like you find at Lowes are pretty flexible and are known to stretch and occasionally split under the prolonged pressure in sump applications. That could put a whole lot of water on the floor if it were to fail. That's the beauty of the standard 5-gallon bucket: It's cheap and durable. You can't use a flat bulkhead though on it's curved surfaces, but you can use uniseals instead. In Bob's (lanman's) case, I think that he used a large, empty "Fresh Step" kitty litter bucket which is rectangular.

 

As for the macro - DSB comparison, one advantage of the RDSB is that it's maintenance free - set it and forget it and uses virtually no power at all (except for a pump). A fuge with macro does take some maintenance and has lighting requirements. A side benefit of macro, however, are the pods that can possibly feed your tank and, if your tangs will eat it, give you a free and natural food source for the bigger critters you keep.

 

My thinking is that my macroalgae require both nutrients and light to grow. Consequently, it's the stuff that's closer to the surface lighting that's doing most of the growing (for implementations that are lit at the surface, that is) and, thus, capturing nutrients. The stuff deeper down is probably not growing that much, but is being forced down deeper into the water column by the growth from above. If that assessment is accurate, the macro that's down deep is really not doing much at all to help with nutrient uptake. After all, if it's not growing, it's not much of a nutrient sink. The added depth does give you a longer time between harvests though. In my situation, I'm using a 20-high which is, in my opinion, does not allow much light penetration once the macro on the surface grows thick. That's why I decided to turn the bottom half into a sand bed (using my live sand from my old 90) and to use the upper half for macro.

 

I tested for nitrates again last night (prompted by this thread) and got a reading of zero using two test kits. I can't say for sure if it's because I'm skimming more heavily now with a much larger skimmer, because I have over doubled my macroalgae, or if it's because I have a nice, remote deep sand bed, since I've changed so much in my system in the last several months. But, I'm very pleased with the zero reading that I'm getting and keeping without dosing carbon sources.

Edited January 6, 2009 by Origami2547